JP2002066739A - Power source control method and power source unit for arc working - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a minimum output current at a light load in a conventional device using a resonance reactor inverter type. SOLUTION: In a power source control method and power source unit for arc working, a saturable reactor resonance tank is connected in between an inverter circuit and a main transformer. In this method and device, a control wire-wound current of a saturable reactor is controlled within a low output current range wherein an output current setting value is small, and the output current is controlled within a high output current range wherein the output current setting value is large by switching the control of the control wire-wound current of the saturable reactor to the control of an inverter frequency f.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply circuit, which converts an output of a DC power supply circuit into a high frequency AC pulse voltage by an inverter circuit, and then converts the output to a voltage suitable for arc machining by a main transformer. The present invention relates to an arc processing power supply control method for converting a pulse voltage into a direct current and using it for arc welding, cutting, heating, and the like, and an improvement in a power supply device.

[0002]

2. Description of the Related Art FIG. 10 shows a resonance reactor inverter I.
The power supply device connection diagram of the power supply device for arc processing of the prior art using NVF is shown. In FIG. 10, a primary rectifier circuit 2 for rectifying the output of a three-phase AC commercial power supply 1 and converting it to DC power
And a smoothing capacitor 3 for smoothing the power converted to DC by the primary rectifier circuit 2 to form a DC power supply circuit DCP.

The switching elements 4 to 7 connected in a bridge form an inverter circuit INV, and the switching elements 4 and 5 and the switching elements 6 and 7 forming opposite sides form a pair, respectively. The switching element drive signals Tra to Trd output from the output switching element drive circuit 22 cause the two switching elements forming a pair to alternately repeat conduction and cutoff to convert the DC power of the primary rectifier circuit 2 to a high-frequency AC pulse voltage. Convert.

The diodes 8 to 11 are connected in parallel to the switching elements 4 to 7 with opposite polarities, respectively.
A reverse voltage is prevented from being applied to the switching elements 4 to 7, and when the switching elements 4 to 7 shift from the conductive state to the cutoff state, they are accumulated in the resonance capacitor 12, the resonance reactor 13, and the main transformer 14. The energy thus obtained is bypassed to the smoothing capacitor 3.

[0005] Switching elements 4 to 7, diode 8
To 11, the resonance capacitor 12 and the resonance reactor 13
Thus, a resonant reactor inverter INVF that converts the output of the smoothing capacitor 3 into a high-frequency substantially sinusoidal alternating current is formed.

[0006] The main transformer 14 converts the output voltage of the resonance reactor inverter INVF into a voltage suitable for arc machining by the main transformer 14. The secondary rectifier circuit 15 rectifies the output of the main transformer 14 and converts it into DC power, and supplies the non-consumable electrode 17 and the workpiece 18 through a DC reactor 16.
To supply.

The output current detector 19 outputs an output current detection signal If. The comparison operation circuit 20 performs a comparison operation between the output current setting signal Ir of the output current setting unit 21 and the output current detection signal If of the output current detector 19 to obtain a comparison operation signal Δ
The value of I = Ir−If is output.

The variable frequency output switching element drive circuit 22 is responsive to the value of the comparison operation signal ΔI from the comparison operation circuit 20 for the frequency of the high-frequency AC pulse voltage output from the inverter circuit INV (hereinafter referred to as the inverter frequency).
f to control the switching element drive signals Tra to T
rd is supplied to the switching elements 4 and 5 or the switching elements 6 and 7 alternately.

FIG. 11 is a timing chart of the switching element drive signal output from the variable frequency output switching element drive circuit 22. Switching element drive signals Tra and T input to switching elements 4 and 5 shown in FIG.
rb and the switching element drive signals Trc and Trd input to the switching elements 6 and 7 have a Pulse Frequency that modulates the pulse frequency with a constant pulse width.
Modulation control (hereinafter referred to as PFM control) is shown.

The variable frequency output switching element driving circuit 22 includes an output current detection signal If and an output current setting signal Ir.
And the comparison operation signal ΔI increases, the inverter current f of the switching element drive signals Tra to Trd shown in FIGS. 11A to 11D is reduced to control the output current Io. Then, when the comparison operation signal ΔI becomes small, the inverter frequency f of the switching element drive signals Tra to Trd shown in FIGS. 11E to 11H is increased to increase or decrease the output current Io.

Normally, when a switching element drive signal is applied to a switching element, the time required for the switching element to change from the cut-off state to the conduction state is shorter than the time required for the switching element to change from the conduction state to the cut-off state. Switching elements 4 and 6 transiently when width
An arm short-circuit occurs in which the switch and the switching elements 5 and 7 become conductive at the same time, and an arm short-circuit current flows through the switching element. In order to prevent this, the variable frequency output switching element drive circuit 22 has a slight pause period between the ON and OFF timings of the opposing drive signals.

FIG. 12 shows a reactor resonance tank LCF formed by a resonance capacitor 12 and a resonance reactor 13.
FIG. 4 is a diagram showing a relationship between the impedance value Z of the inverter and the inverter frequency f. The capacitance of the resonance capacitor 12 is C, the inductance of the resonance reactor 13 is L, the resistance of the wiring of the reactor resonance tank LCF, the resonance capacitor 1
2 and the resistance of the resonant reactor 13 are neglected.
The impedance value Z of the reactor resonance tank LCF is
Z = | 2πfL−1 / 2πfC |

The resonance reactor inverter INVF includes:
There is a resonance frequency fr inherent to the circuit, and this resonance frequency f
r is calculated from the equation fr = 1 / (2π√LC). From the above equation, when the inverter frequency f approaches the resonance frequency fr, the impedance value Z of the reactor resonance tank LCF becomes the lowest, and the output current of the primary rectifier circuit 2 and the smoothing capacitor 3 is applied to the primary winding of the main transformer 14. The maximum output power Io is obtained on the secondary side.

When the inverter frequency f approaches the resonance frequency fr shown in FIG. 12, an excessive current flows through the reactor resonance tank LCF and the switching element is destroyed. The frequency fs is set to a value slightly higher than the resonance frequency fr. The maximum output current Io is obtained at the minimum inverter frequency fs. When the inverter frequency f is increased or decreased from the minimum inverter frequency fs, the impedance value Z of the reactor resonance tank LCF increases or decreases. The voltage applied to the primary winding decreases and the output current Io is controlled. Therefore, the output current Io is controlled by increasing or decreasing the inverter frequency f from the set minimum inverter frequency fs to the maximum inverter frequency fh whose upper limit is limited by the characteristics of the switching element used.

[0015]

In a conventional apparatus using a resonant reactor inverter INVF shown in FIG.
When the minimum inverter frequency fs is lowered, the main transformer 14 and the DC reactor 16 become large.
I want to set s higher. On the other hand, if the inverter frequency becomes high, it becomes impossible to respond (follow) due to the characteristics of the switching element used, so that the maximum inverter frequency fh that can be set is limited. Therefore, in order to output the minimum output current at the time of light load, the reactance value X of the resonance reactor 13 must be increased to increase or decrease the impedance value Z of the reactor resonance tank LCF. In order to increase the impedance value Z, the impedance value Z can be increased or decreased by increasing the reactor value X by increasing the minimum inverter frequency fs. However, if the minimum inverter frequency fs is increased, the inverter frequency f
Becomes narrower, and it becomes impossible to control the output current Io up to a light load range of the power supply device. Therefore, to supply a light load output current of the power supply device, there is a method of increasing or decreasing the number of turns of the secondary winding of the main transformer 14, but this leads to an increase in the size of the entire device and an increase in cost.

[0016]

The invention of the method of claim 1 at the time of filing is the invention according to the first embodiment, wherein the saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is provided. 3 is a power supply control method for controlling the output current Io by increasing or decreasing the impedance value of the saturable reactor resonance tank LCR as shown in FIG. 3, and as shown in FIG. Inverter circuit INV
And outputs the switching element drive signals Tra to Trd, converts the output of the DC power supply circuit DCP into a high frequency AC pulse voltage by an inverter circuit INV including the switching elements 4 to 7, and converts the high frequency AC pulse voltage by the main transformer 14. In the arc machining power supply control method for converting to a voltage suitable for arc machining, a switching element drive signal Tra to Trd having a predetermined fixed inverter frequency fa with the same pulse width is output to the switching elements 4 to 7 and a direct current is output. The output of the power supply circuit DCP is converted into a high-frequency AC pulse voltage, and a saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is connected between the inverter circuit INV and the main transformer 14. , The saturable reactor 26
This is a method for controlling the output current Io by increasing or decreasing the control winding current Ic and increasing or decreasing the inductance value L of the main winding to increase or decrease the impedance value Z of the saturable reactor resonance tank LCR.

The invention of claim 2 at the time of filing is the invention according to the first embodiment which embodies the method of claim 1 at the time of filing, wherein the output current setting signal Ir and the output current detection signal I
f and the control winding current I of the saturable reactor 26 in accordance with the value of the comparison operation signal ΔI = Ir−If
The output current I is increased or decreased by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR.
1 is a power control method for controlling a switching element drive signal Tra to Trd to an inverter circuit INV including switching elements 4 to 7 to output an output of a DC power supply circuit DCP as shown in FIG. In the arc machining power supply control method of converting the high-frequency AC pulse voltage into a voltage suitable for arc machining by the main transformer 14 by converting the high-frequency AC pulse voltage into the high-frequency AC pulse voltage by the inverter circuit INV composed of 4 to 7, the same pulse width is used. The switching element driving signals Tra to Trd having a predetermined fixed inverter frequency fa are output to the switching elements 4 to 7, and the output of the DC power supply circuit DCP is converted into a high-frequency AC pulse voltage.
V and the main transformer 14, a saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is connected, and the output current setting signal I
The control winding current Ic of the saturable reactor 26 is increased / decreased and the inductance value L of the main winding is increased / decreased in accordance with the value of a comparison operation signal ΔI = Ir−If obtained by comparing r with the output current detection signal If. Saturable reactor resonance tank L
This is a power supply control method for arc machining in which the output current Io is controlled by increasing or decreasing the impedance value Z of CR.

The invention of claim 3 at the time of filing is the invention according to the first embodiment which embodies the invention of claim 1 at the filing time or the method of claim 2 at the filing time. Instead of the switching element drive signals Tra to Trd having the determined fixed inverter frequency fa, a predetermined first fixed inverter frequency fa with the same pulse width and a second fixed frequency higher than the first fixed inverter frequency fa. FIG. 1 shows a power supply control method for controlling an output current Io by increasing or decreasing the impedance value Z of a saturable reactor resonance tank LCR using switching element drive signals Tra to Trd switched to an inverter frequency fb. As described above, the switching element drive signals Tra to Trd are supplied to the inverter circuit INV including the switching elements 4 to 7. Then, the output of the DC power supply circuit DCP is converted into a high-frequency AC pulse voltage by the inverter circuit INV including the switching elements 4 to 7, and the high-frequency AC pulse voltage is converted by the main transformer 14 into a voltage suitable for arc machining. In the arc machining power supply control method, a switching element drive signal is switched by switching between a first fixed inverter frequency fa predetermined with the same pulse width and a second fixed inverter frequency fb higher than the first fixed inverter frequency fa. Tra to Trd are output to the switching elements 4 to 7, and the DC power supply circuit DC
The output of P is converted into a high-frequency AC pulse voltage, and a saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is connected between the inverter circuit INV and the main transformer 14, and Arc processing power supply control for controlling the output current Io by increasing or decreasing the control winding current Ic of the saturable reactor 26 and increasing or decreasing the inductance value L of the main winding to increase or decrease the impedance value Z of the saturable reactor resonance tank LCR. Is the way.

The invention of the method of claim 4 at the time of filing is described in the second embodiment.
As shown in FIG. 5, in the low output current range, the frequency (inverter frequency) f of the high-frequency AC pulse voltage converted by the inverter circuit INV is increased or decreased to change the impedance value of the saturable reactor resonance tank LCR. The output current Io is controlled by increasing or decreasing Z, and in the high output current range, the inductance value L of the saturable reactor main winding Lm is increased or decreased to increase or decrease the impedance value Z of the saturable reactor resonance tank LCR. A power supply control method for controlling Io,
As shown in FIG. 4, a switching element drive signal Tr is supplied to an inverter circuit INV composed of switching elements 4 to 7.
a to Trd, and outputs the output of the DC power supply circuit DCP to the inverter circuit IN including the switching elements 4 to 7.
V, a high frequency AC pulse voltage is converted into a high frequency AC pulse voltage, and the high frequency AC pulse voltage is converted into a voltage suitable for arc processing by the main transformer 14. A saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is connected therebetween, and a frequency (inverter frequency) f of a high-frequency AC pulse voltage converted by the inverter circuit INV in a predetermined low output current range. The output current Io is controlled by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR, and in the high output current range exceeding the predetermined low output current range, the inductance of the saturable reactor main winding Lm is controlled. By increasing or decreasing the value L, the saturable reactor It is arc machining power supply control method for controlling an output current Io by increasing or decreasing the impedance value Z of the LCR.

The invention of the method according to claim 5 at the time of filing is the invention according to the second embodiment which embodies the invention of the method according to claim 4 at the time of filing, and as shown in FIG. The switching element drive signals Tra to Trd are output to an inverter circuit INV composed of
The output of P is converted into a high-frequency AC pulse voltage by an inverter circuit INV including switching elements 4 to 7,
In the arc machining power supply control method for converting the high frequency AC pulse voltage into a voltage suitable for arc machining by the main transformer, a resonance capacitor 12 and a saturable reactor 26 are provided between the inverter circuit INV and the main transformer. Saturable reactor resonance tank L formed by
An inverter / reactor switching output current set value Irt for switching from control of the frequency (inverter frequency) f of the high-frequency AC pulse voltage to control of the control winding current Ic of the saturable reactor 26 by connecting a CR to the output current setting signal When Ir is the minimum output current set value Ir1, the control winding current Ic of the saturable reactor 26 is set to the minimum control winding current Ic1, and the inverter frequency f is set to the maximum inverter frequency fh. The current setting signal Ir is changed from the minimum output current setting value Ir1 to the inverter
Until the reactor switching output current set value Irt, the control winding current Ic is maintained at the minimum control winding current Ic1, and the inverter frequency f is increased or decreased according to the increase or decrease of the output current setting signal Ir.
Is increased or decreased in the range from the maximum inverter frequency fh to the minimum inverter frequency fs, so that the output current Io
Further, while the output current setting signal Ir is between the inverter / reactor switching output current setting value Irt and the maximum output current setting value Ir3, the inverter frequency f is maintained at the minimum inverter frequency fs and the output current setting signal Ir is maintained. The control winding current Ic of the saturable reactor 26 is increased or decreased from the minimum control winding current Ic1 to the maximum control winding current Ic2 in accordance with the increase or decrease of Ir, and the inductance value L of the saturable reactor main winding Lm is increased or decreased. This is a power supply control method for arc machining in which the output current Io is controlled by increasing or decreasing the impedance value Z of the resonance tank LCR.

The invention of claim 6 at the time of filing is the invention according to the second embodiment which embodies the invention of claim 5 at the time of filing, and as shown in FIG. An arc machining power supply control method for converting an output into a high-frequency AC pulse voltage by an inverter circuit INV including switching elements 4 to 7 and converting the high-frequency AC pulse voltage into a voltage suitable for arc machining by the main transformer 14, A saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is connected between the inverter circuit INV and the main transformer 14, so that the set value of the output current setting signal Ir increases and the AC pulse voltage frequency (inverter frequency) f
Of the inverter / reactor switching output current Irt when switching from the control of the saturable reactor 26 to the control of the control winding current Ic of the saturable reactor 26, and the output current setting signal Ir
Is the minimum output current set value Ir1, the control winding current Ic of the saturable reactor 26 is set to the minimum control winding current Ic1, the inductance value L of the saturable reactor main winding Lm is maximized, and the inverter By setting the frequency f to the maximum inverter frequency fh, the impedance value Z of the saturable reactor resonance tank LCR is maximized, and then the output current setting signal Ir is changed from the minimum output current set value Ir1 to the inverter / reactor switching output. Until the current setting value Irt, the control winding current Ic is maintained at the minimum control winding current Ic1, and the output current setting signal Ir
The output current Io is controlled by increasing / decreasing the inverter frequency f in the range from the maximum inverter frequency fh to the minimum inverter frequency fs according to the increase / decrease in the impedance value Z of the saturable reactor resonance tank LCR. While the signal Ir is between the inverter / reactor switching output current setting value Irt and the maximum output current setting value Ir3, the output current setting signal Ir is maintained while maintaining the inverter frequency f at the minimum inverter frequency fs.
Control winding current I of the saturable reactor 26 according to the
c is changed from the minimum control winding current Ic1 to the maximum control winding current Ic.
This is a power supply control method for arc processing in which the output current Io is controlled by increasing or decreasing the inductance value L of the saturable reactor main winding Lm by increasing or decreasing the impedance value Z to 2 and increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR.

The invention of claim 7 at the time of filing is the invention according to the second embodiment which embodies the invention of claim 6 at the time of filing, and as shown in FIG. An arc machining power supply control method for converting an output into a high-frequency AC pulse voltage by an inverter circuit INV including switching elements 4 to 7 and converting the high-frequency AC pulse voltage into a voltage suitable for arc machining by the main transformer 14, The saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is connected between the inverter circuit INV and the main transformer 14, and the set value of the output current setting signal Ir increases to increase In the output current range, the control winding current Ic of the saturable reactor 26 is controlled by controlling the frequency (inverter frequency) f of the high-frequency AC pulse voltage. An inverter / reactor switching output current set value Irt for switching to control is predetermined, and when the output current setting signal Ir is smaller than the inverter / reactor switching output current set value Irt (Ir <Irt), the minimum control winding is set. The current Ic1 is supplied to the saturable reactor 26 to maintain the control winding current Ic at the minimum control winding current Ic1, to maximize the inductance value L of the saturable reactor main winding Lm, and to set the output current setting signal Ir Operation signal ΔI obtained by comparing the output current detection signal If with the output current detection signal If
= Ir−If, the switching element driving signals Tra to Trd in a range from a predetermined maximum inverter frequency fh to a minimum inverter frequency fs are supplied to the switching elements 4 to 7 in accordance with the value of Ir−If, and the saturable reactor resonance tank LCR is supplied. The output current Io is controlled by increasing / decreasing the impedance value Z of the inverter, and then is larger than the inverter / reactor switching output current set value Irt (Ir> I
rt), the switching element drive signals Tra to Trd having the minimum inverter frequency fs are supplied to the switching elements 4 to 7 to maintain the inverter frequency f at the minimum inverter frequency fs and the comparison operation signal ΔI =
According to the value of Ir-If, a control winding current Ic in a range from a predetermined minimum control winding current Ic1 to a maximum control winding current Ic2 is supplied to the saturable reactor 26, and the saturable reactor main winding is controlled. This is a power control method for arc machining in which the output current Io is controlled by increasing or decreasing the inductance value L of Lm to increase or decrease the impedance value Z of the saturable reactor resonance tank LCR.

The invention of claim 8 at the time of filing is the invention according to the second embodiment which embodies the invention of claim 7 at the time of filing, and as shown in FIG. An arc machining power supply control method for converting an output into a high-frequency AC pulse voltage by an inverter circuit INV including switching elements 4 to 7 and converting the high-frequency AC pulse voltage into a voltage suitable for arc machining by the main transformer 14, The saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is connected between the inverter circuit INV and the main transformer 14, and the set value of the output current setting signal Ir increases to increase In the output current range, the control winding current Ic of the saturable reactor 26 is controlled by controlling the frequency (inverter frequency) f of the high-frequency AC pulse voltage. Defines the inverter reactor switching output current setting value Irt when switching to control in advance, when the output current setting signal Ir exceeds the inverter reactor switching output current setting value Irt, the inverter frequency f
, Outputs an inverter / reactor switching reference signal It for switching the control to the control of the control winding current Ic of the saturable reactor 26, compares the output current setting signal Ir with the inverter / reactor switching reference signal It, and outputs the output current. When the setting signal Ir is smaller than the inverter / reactor switching reference signal It (Ir <It), the inverter / reactor switching signal St becomes low, and the minimum control winding current Ic1 is supplied to the saturable reactor 26. To maintain the control winding current Ic at the minimum control winding current Ic1,
A comparison operation signal ΔI = Ir−I obtained by maximizing the inductance value L of the saturable reactor main winding Lm and comparing the output current setting signal Ir with the output current detection signal If.
In accordance with the value of f, a predetermined maximum inverter frequency fh
The switching element drive signals Tra to Trd in a range from the minimum inverter frequency fs to the switching element 4
Through 7 to saturable reactor resonance tank LCR
The output current Io is controlled by increasing or decreasing the impedance value Z of the inverter. When the output current setting signal Ir becomes larger than the inverter / reactor switching reference signal It (Ir> Irt), the inverter / reactor switching is performed. The signal St becomes High, and the switching element drive signals Tra to Trd of the minimum inverter frequency fs
To the switching elements 4 to 7 to maintain the inverter frequency f at the minimum inverter frequency fs,
In accordance with the value of the comparison operation signal ΔI = Ir−If, a predetermined minimum control winding current Ic1 to a maximum control winding current Ic1 are determined.
By passing a control winding current Ic in the range up to c2 to the saturable reactor 26 to increase or decrease the inductance value L of the saturable reactor main winding Lm and increase or decrease the impedance value Z of the saturable reactor resonance tank LCR. This is a power supply control method for arc machining for controlling the output current Io.

The invention of the method of claim 9 at the time of filing is described in the third embodiment.
5, contrary to FIG. 5 described above, as shown in FIG. 7, in a low output current range, the inductance value L of the saturable reactor main winding Lm is increased or decreased to reduce the saturable reactor resonance tank LCR. The output current Io is controlled by increasing / decreasing the impedance value Z. In the high output current range, the frequency of the high-frequency AC pulse voltage (inverter frequency)
The output current I is increased or decreased by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR.
6 is a power supply control method for controlling a switching element drive signal Tra to Trd to an inverter circuit INV including switching elements 4 to 7 to output an output of a DC power supply circuit DCP as shown in FIG. An arc machining power supply control method for converting a high-frequency AC pulse voltage into a voltage suitable for arc machining with the main transformer 14 by converting the high-frequency AC pulse voltage into a voltage suitable for arc machining with the inverter circuit INV comprising 4 to 7; A saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is connected between the main transformer 14 and the main transformer 14, and an inductance value of the saturable reactor main winding Lm in a predetermined low output current range. L to increase or decrease the impedance of the saturable reactor resonance tank LCR. Controlling the output current Io by increasing or decreasing the dance value Z, the advance in the high output current range exceeding the low output current range that defines the inverter circuit INV
This is a power control method for arc machining in which the output current Io is controlled by increasing or decreasing the frequency (inverter frequency) f of the high-frequency AC pulse voltage to be converted by changing the impedance value Z of the saturable reactor resonance tank LCR.

The invention of the method of claim 10 at the time of filing is an invention according to a third embodiment that embodies the method of the invention of claim 9 at the time of filing, and is shown in FIG. like,
In the low output current range, the output current Io is controlled by increasing or decreasing the inductance value L of the saturable reactor main winding Lm and increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR. An arc machining power supply control method for controlling an output current Io by increasing or decreasing an impedance value Z of a saturable reactor resonance tank LCR by increasing or decreasing a voltage frequency (inverter frequency) f, as shown in FIG. The switching element drive signals Tra to Trd are output to the inverter circuit INV including the switching elements 4 to 7, and the output of the DC power supply circuit DCP is converted into the high frequency AC pulse voltage by the inverter circuit INV including the switching elements 4 to 7, High-frequency AC pulse voltage to main transformer 14 In the arc machining power supply control method for converting to a voltage suitable for arc machining, a saturable reactor resonance tank formed by the resonance capacitor 12 and the saturable reactor 26 between the inverter circuit INV and the main transformer 14 is provided. The reactor / inverter switching output current set value I for switching the control of the frequency (inverter frequency) f of the high-frequency AC pulse voltage to the control of the control winding current Ic of the saturable reactor 26 by connecting an LCR.
When the output current setting signal Ir for which rv is predetermined is the minimum output current setting value Ir1, the control winding current Ic of the saturable reactor 26 is set to the minimum control winding current Ic1, and the inverter frequency f is set to the maximum inverter frequency. fh. Then, while the output current setting signal Ir is between the minimum output current setting value Ir1 and the reactor-inverter switching output current setting value Irv, the inverter frequency f is maintained at the maximum inverter frequency fh. Current setting signal I
r, the control winding current Ic of the saturable reactor 26 is changed from the minimum control winding current Ic1 to the maximum control winding current Ic.
The output current Io is controlled by increasing / decreasing the output current to c2.
During the period from the inverter switching output current setting value Irv to the maximum output current setting value Ir3, the control winding current Ic is maintained at the maximum control winding current Ic2, and the inverter frequency f is increased according to the increase and decrease of the output current setting signal Ir. This is a power supply control method for arc machining in which the output current Io is controlled by increasing or decreasing the frequency from a frequency fh to a minimum inverter frequency.

The invention of claim 11 at the time of filing is the invention according to the third embodiment which embodies the invention of claim 10 at the time of filing, and as shown in FIG.
The switching element drive signals Tra to Trd are output to the inverter circuit INV including the switching elements 4 to 7, and the output of the DC power supply circuit DCP is converted into a high-frequency AC pulse voltage by the inverter circuit INV including the switching elements 4 to 7. In the arc machining power supply control method for converting a voltage into a voltage suitable for arc machining by the main transformer 14, a resonance capacitor 12 and a saturable reactor 26 are formed between the inverter circuit INV and the main transformer 14. A saturable reactor resonance tank LCR is connected, and a reactor-inverter switching output current set value Irv for switching from control of the control winding current Ic of the saturable reactor 26 to control of the frequency (inverter frequency) f of the high-frequency AC pulse voltage is set in advance. And the output current setting signal Ir When the small output current setting value Ir1,
The control winding current Ic of the saturable reactor 26 is set to the minimum control winding current Ic1 to maximize the inductance value L of the saturable reactor main winding Lm, and the inverter frequency f is set to the maximum inverter frequency fh. To maximize the impedance value Z of the saturable reactor resonance tank LCR, and then output current setting signal Ir
Is maintained between the minimum output current setting value Ir1 and the reactor / inverter switching output current setting value Irv, the inverter frequency f is maintained at the maximum inverter frequency fh, and the saturable reactor 26 is increased or decreased according to the increase or decrease of the output current setting signal Ir.
The output current Io is controlled by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR by increasing or decreasing the control winding current Ic from the minimum control winding current Ic1 to the maximum control winding current Ic2. When the setting signal Ir is between the reactor / inverter switching output current setting value Irv and the maximum output current setting value Ir3,
By maintaining the control winding current Ic at the maximum control winding current Ic2 and increasing or decreasing the inverter frequency f in the range from the maximum inverter frequency fh to the minimum inverter frequency fs according to the increase or decrease of the output current setting signal Ir, a saturable reactor resonance tank is provided. This is a power supply control method for arc machining in which the output current Io is controlled by increasing or decreasing the impedance value Z of the LCR.

The invention of claim 12 at the time of filing is the invention according to the third embodiment which embodies the invention of claim 11 at the time of filing, and as shown in FIG.
Is output to the inverter circuit INV including the switching elements 4 to 7 so that the switching element driving signals Tra to Tr
d, converting the high-frequency AC pulse voltage into a high-frequency AC pulse voltage, and converting the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14. A saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 is connected between the output current setting signal Ir and the saturable reactor in a high output current range. The reactor / inverter switching output current set value Irv for switching from the control of the control winding current Ic to the control of the frequency of the high-frequency AC pulse voltage (inverter frequency) f is determined in advance, and the output current setting signal Ir is When it is smaller than the switching output current set value Irv (Ir <Irv), the maximum inverter A switching element driving signal Tra to Trd frequency fh by energizing the switching elements 4 to 7, the maximum inverter frequency f inverter frequency f
h, and a comparison operation signal ΔI = Ir obtained by comparing the output current setting signal Ir with the output current detection signal If.
According to the value of -If, the control winding current Ic in the range from the minimum control winding current Ic1 to the maximum control winding current Ic2 is supplied to the saturable reactor 26, and the inductance value of the saturable reactor main winding Lm. The output current Io is controlled by increasing / decreasing L to increase / decrease the impedance value Z of the saturable reactor resonance tank LCR. Next, the output current setting signal Ir is larger than the reactor / inverter switching output current setting value Irv ( When Ir> Irv), the maximum control winding current Ic2 is supplied to the saturable reactor 26 to maintain the control winding current Ic at the maximum control winding current Ic2, and the inductance value L of the saturable reactor main winding Lm is reduced.
And the switching element drive signals Tra to Trd in the range from the predetermined maximum inverter frequency fh to the predetermined minimum inverter frequency fs are supplied to the switching elements 4 to 7 in accordance with the value of the comparison operation signal ΔI. A power supply control method for arc machining in which the output current Io is controlled by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR.

The invention of claim 13 at the time of filing is the invention according to the third embodiment which embodies the invention of the method of claim 12 at the time of filing, and as shown in FIG.
An arc machining power supply control method for converting the output of the above into a high-frequency AC pulse voltage by an inverter circuit INV comprising switching elements 4 to 7 and converting the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14, The inverter circuit INV and the main transformer 1
4 and the resonance capacitor 12 and the saturable reactor 2
6 and the saturable reactor resonance tank LC
By connecting R, the control value of the control winding current Ic of the saturable reactor 26 to the control of the frequency (inverter frequency) f of the high-frequency AC pulse voltage is controlled in the high output current range when the set value of the output current setting signal Ir increases. When the output current setting signal Ir exceeds the reactor / inverter switching output current setting value Irv, the control of the control winding current Ic of the saturable reactor 26 is performed. A reactor / inverter switching reference signal Iv for switching to the control of the frequency f is output, and the output current setting signal Ir is compared with the reactor / inverter switching reference signal Iv. When it is smaller than Iv (Ir <Iv), the reactor / inverter switching is performed. No. Sv is turned Low, the switching element driving signal of the maximum inverter frequency fh Tra
Through Trd to the switching elements 4 through 7 to maintain the inverter frequency f at the maximum inverter frequency fh, the output current setting signal Ir and the output current detection signal I
The control winding current Ic in the range from the predetermined minimum control winding current Ic1 to the maximum control winding current Ic2 is determined in accordance with the value of the comparison calculation signal ΔI = Ir−If obtained by comparing f with the saturable reactor 26. To control the output current Io by increasing or decreasing the inductance value L of the saturable reactor main winding Lm and increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR. Then, the output current setting signal Ir Is larger than the reactor-inverter switching reference signal Iv (Ir> Iv),
When the inverter switching signal Sv becomes High, the maximum control winding current Ic2 is supplied to the saturable reactor 26 to maintain the control winding current Ic at the maximum control winding current Ic2, and the saturable reactor main winding Lm The switching element drive signal Tr in a range from a predetermined maximum inverter frequency fh to a predetermined minimum inverter frequency fs in accordance with the value of the comparison operation signal ΔI while maximizing the inductance value L.
a through Trd are supplied to the switching elements 4 through 7,
This is a power supply control method for arc machining in which the output current Io is controlled by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR.

The method according to claim 14 at the time of filing is the invention according to the fourth embodiment. As shown in FIG. 8, the inverter circuit INV including the switching elements 4 to 7 supplies switching element drive signals Tra to Trd. And a saturable reactor resonance formed by the resonant capacitor 12 and the saturable reactor 26 connected between the inverter circuit INV for converting the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage and the main transformer 14. The inverter circuit INV including the tanks LCR and the switching elements 4 to 7 includes switching element drive signals Tra to Tr.
d, the output of the DC power supply circuit DCP is converted to a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is converted by the main transformer 14 into a voltage suitable for arc processing. Power circuit DCP
A resonance capacitor 1 is connected between an inverter circuit INV for converting the output of the inverter into a high-frequency AC pulse voltage and the main transformer 14.
2 and a saturable reactor resonance tank LCR formed by the saturable reactor 26 to increase and decrease the inductance value L of the saturable reactor main winding Lm,
When the output current Io suddenly changes, the inverter frequency f of the switching element drive signals Tra to Trd is changed.
To increase or decrease the impedance value Z of the saturable reactor resonance tank LCR to control the output current Io
Is a power supply control method for arc processing for controlling the power.

The invention of claim 15 at the time of filing is the invention according to the fourth embodiment which embodies the invention of claim 14 at the time of filing, and as shown in FIG.
The switching element drive signals Tra to Trd are output to the inverter circuit INV composed of the inverters 7 to 7 to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage. In the arc machining power supply control method for converting the voltage into a converted voltage, the saturable reactor resonance tank L formed by the resonance capacitor 12 and the saturable reactor 26 connected between the inverter circuit INV and the main transformer 14 is provided.
A comparison operation signal ΔI = Ir−I obtained by connecting the CR and comparing the output current setting signal Ir with the output current detection signal If.
The control winding current I of the saturable reactor 26 according to f
c is output to increase or decrease the inductance value L of the saturable reactor main winding Lm, and the comparison operation signal ΔI, which has been sequentially calculated, suddenly changes to a predetermined allowable fluctuation value ΔI.
y, the inverter frequency f of the switching element drive signals Tra to Trd is controlled in accordance with the value of the comparison operation signal ΔI, and the saturable reactor resonance tank LCR
Is a power supply control method for arc machining in which the output current Io is controlled by increasing or decreasing the impedance value Z of the power supply.

The invention of the method according to claim 16 at the time of filing is the invention according to the fourth embodiment which embodies the invention of the method according to claim 15 at the time of filing, and as shown in FIG.
The switching element drive signals Tra to Trd are output to the inverter circuit INV composed of the inverters 7 to 7 to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage. In the arc machining power supply control method for converting the voltage into a converted voltage, the saturable reactor resonance tank L formed by the resonance capacitor 12 and the saturable reactor 26 connected between the inverter circuit INV and the main transformer 14 is provided.
A comparison operation signal ΔI = Ir−I obtained by connecting the CR and comparing the output current setting signal Ir with the output current detection signal If.
The control winding current I of the saturable reactor 26 according to f
c is increased or decreased from a predetermined minimum control winding current Ic1 to a maximum control winding current Ic2 so that the saturable reactor main winding L
In addition to increasing and decreasing the inductance value L of m, when the comparison operation signal ΔI calculated successively changes rapidly and exceeds a predetermined allowable fluctuation value ΔIy, a predetermined fluctuation according to the value of the comparison operation signal ΔI Allowable upper limit inverter frequency f
By controlling the inverter frequency f of the switching element drive signals Tra to Trd in the range from k to the permissible lower limit inverter frequency ft, the saturable reactor resonance tank L
This is a power supply control method for arc machining in which the output current Io is controlled by increasing or decreasing the impedance value Z of CR.

The method invention of claim 17 at the time of application is based on claim 5 at the time of application, claim 6 at the time of application, claim 7 at the time of application, claim 8 at the time of application, claim 9 at the time of application, or claim 10 at the time of application.
Alternatively, the minimum control winding current Ic1 according to the invention of claim 11 at the time of filing, claim 12 at the time of filing, or claim 13 at the filing is a control winding current Ic that maximizes the inductance value L of the saturable reactor main winding Lm. The maximum control winding current Ic2 is the control winding current Ic that minimizes the inductance value L of the saturable reactor main winding Lm, and the minimum inverter frequency fs is that the inductance value L of the saturable reactor main winding Lm is constant. Saturable reactor resonance tank LC
Inverter circuit I that minimizes the impedance value Z of R
The frequency (inverter frequency) f of the high-frequency AC pulse voltage converted by the NV is saturable reactor resonance tank L when the maximum inverter frequency fh and the inductance value L of the saturable reactor main winding Lm are constant.
This is an arc machining power supply control method in which the frequency (inverter frequency) f of the high-frequency AC pulse voltage converted by the inverter circuit INV that maximizes the CR impedance value Z is:

The invention of the device of claim 18 at the time of filing is an invention of a device for implementing the power supply control method described in the first embodiment, and as shown in FIG. 1, an inverter circuit INV comprising switching elements 4 to 7 To output switching element drive signals Tra to Trd to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage, and convert the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14. Switching element drive signals Tra to Tr having a predetermined fixed inverter frequency fa with the same pulse width as the switching elements in the power supply device for
and a saturable reactor main winding Lm in accordance with the value of the control winding current Ic that energizes the saturable reactor control winding Lc.
Saturable reactor 26 for controlling the inductance value L of
And a saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 between the inverter circuit INV and the main transformer 14, and an output current Io to output an output current setting signal Ir. An output current setter 21, an output current detector 19 that detects an output current Io and outputs an output current detection signal If, and a comparison operation by comparing the output current setting signal Ir with the output current detection signal If A comparison operation circuit 20 for outputting a signal ΔI = Ir−If; and a variable current output for outputting a control winding current Ic for increasing or decreasing the inductance value L of the saturable reactor main winding Lm according to the value of the comparison operation signal ΔI. This is a power supply device for arc machining including a reactor control circuit 24.

The device invention of claim 19 at the time of filing is an invention of a device for implementing the power supply control method according to the second embodiment, and as shown in FIG. 4, an inverter circuit INV comprising switching elements 4 to 7. To output switching element drive signals Tra to Trd to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage, and convert the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14. In the power supply device, a saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 between the inverter circuit INV and the main transformer 14, and an output current Io
, An output current setting unit 21 that outputs an output current setting signal Ir, an output current detector 19 that detects an output current Io and outputs an output current detection signal If, and the output current setting signal Ir and the output A comparison operation circuit 20 that performs a comparison operation on the current detection signal If to output a comparison operation signal ΔI = Ir−If; and a frequency of the high-frequency AC pulse voltage (inverter frequency ) The inverter / reactor switching output current set value Irt for switching from the control of f to the control of the control winding current Ic of the saturable reactor 26 is determined in advance, and the output current setting signal Ir is set to the inverter / reactor switching output current set value Irt. Is smaller, the switching element drive signals Tra to Trd of the inverter frequency f are changed according to the value of the comparison operation signal ΔI. When the output current setting signal Ir is larger than the inverter / reactor switching output current setting value Irt, the switching element drive signal T of the minimum inverter frequency fs is output to the switching elements 4 to 7.
When the output current setting signal Ir is larger than the inverter / reactor switching output current setting value Irt, the switching element driving signals Tra to Trd having the minimum inverter frequency fs are output to the switching element 4.
When the output current setting signal Ir is smaller than the inverter / reactor switching output current setting value Irt, the saturable reactor control winding Lc is set in advance. A predetermined minimum control winding current Ic1 is output, and when the output current setting signal Ir is larger than the inverter / reactor switching output current setting value Irt, the control winding current Ic is determined according to the value of the comparison operation signal ΔI. And a constant / variable current output switching reactor control circuit 31 that outputs the same.

The invention of the device according to claim 20 at the time of filing is an embodiment of the device according to claim 19 at the time of filing, and as shown in FIG. Switching element drive signal Tra
In the arc machining power supply device that outputs Trd to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage and convert the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14, A saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 connected between the circuit INV and the main transformer 14, and an output current Io
, An output current setting unit 21 that outputs an output current setting signal Ir, an output current detector 19 that detects an output current Io and outputs an output current detection signal If, and the output current setting signal Ir and the output A comparison operation circuit 20 that performs a comparison operation on the current detection signal If to output a comparison operation signal ΔI = Ir−If; and a frequency of the high-frequency AC pulse voltage (inverter frequency ) The inverter / reactor switching output current set value Irt for switching from the control of f to the control of the control winding current Ic of the saturable reactor 26 is determined in advance, and the output current setting signal Ir is set to the inverter / reactor switching output current set value Irt. Exceeds the inverter frequency f, control is switched to control of the control winding current Ic of the saturable reactor 26. Inverter reactor switching reference signal setting circuit 30 for outputting a vector switching reference signal It
Is compared with the output current setting signal Ir and the inverter / reactor switching reference signal It.
When r becomes the inverter / reactor switching reference signal It, the inverter / reactor switching comparison circuit 29 for switching the inverter / reactor switching signal St from Low to High and the switching element drive signals Tra to Trd of the minimum inverter frequency fs are output. A minimum inverter frequency signal generation circuit FS for generating a signal of the minimum inverter frequency fs, and the comparison operation signal Δ when the inverter / reactor switching signal St is Low.
The switching element driving signals Tra to Trd of the inverter frequency f are changed according to the value of I to the switching elements 4 to 7.
And when the inverter / reactor switching signal St is High, the switching element drive of the inverter frequency f ranging from the predetermined maximum inverter frequency fh to the minimum inverter frequency fs in accordance with the value of the comparison operation signal ΔI. A constant / variable frequency output switching element driving circuit 28 for outputting signals Tra to Trd to the switching elements 4 to 7 and a minimum control winding current Ic1 for maximizing the inductance value L of the saturable reactor main winding Lm. A minimum control winding current generating circuit IC1 for outputting to the saturable reactor control winding Lc, and a minimum control winding current Ic1 for outputting when the inverter / reactor switching signal St is Low; When the signal St is High, according to the value of the comparison operation signal ΔI, Predetermined minimum control winding current Ic
A constant / variable current output switching reactor control circuit 31 that outputs a control winding current Ic in a range from 1 to a maximum control winding current Ic2 to a saturable reactor control winding Lc.

The invention of the device according to claim 21 at the time of filing is an embodiment of the device according to claim 20 at the time of filing, and as shown in FIG. Switching element drive signal Tra
In the arc machining power supply device for outputting Trd to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage and converting the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14, an inverter is provided. A saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 connected between the circuit INV and the main transformer 14, and an output for setting an output current Io and outputting an output current setting signal Ir The current setter 21 detects an output current Io and outputs an output current detection signal If
And an output current detector 19 that outputs the output current setting signal Ir and the output current detection signal If to output a comparison operation signal ΔI = Ir−If.
0, the set value of the output current setting signal Ir increases, and the frequency of the high-frequency AC pulse voltage (inverter frequency) f
Of the inverter / reactor switching output current Irt when switching from the control of the saturable reactor 26 to the control of the control winding current Ic of the saturable reactor 26, and the output current setting signal Ir
Is the inverter / reactor switching output current set value Ir
When t exceeds t, an inverter / reactor switching reference signal setting circuit 30 for outputting an inverter / reactor switching reference signal It for switching from control of the inverter frequency f to control of the control winding current Ic of the saturable reactor 26; Ir is compared with the inverter / reactor switching reference signal It. When the output current setting signal Ir becomes the inverter / reactor switching reference signal It, the inverter / reactor switching signal St is changed from low to high.
h / inverter / reactor switching comparison circuit 2
9, a NOT circuit 36 for outputting an inverter / reactor switching inversion signal Sth obtained by inverting the inverter / reactor switching signal St, and a signal having the minimum inverter frequency fs for outputting the switching element drive signals Tra to Trd having the minimum inverter frequency fs. And a minimum inverter frequency signal generating circuit FS for generating the inverter / reactor switching signal St when the inverter / reactor switching signal St is Low.
When the reactor switching signal St is Low, it goes to the L side and outputs the comparison operation signal ΔI.
An inverter frequency signal switching circuit SW1 that goes high when the reactor switching signal St is high and generates a signal with the minimum inverter frequency fs; and a value of the comparison operation signal ΔI when the inverter frequency signal switching circuit SW1 is low. The constant / variable frequency output switching switching element driving circuit 28 outputs switching element driving signals Tra to Trd having an inverter frequency f ranging from a predetermined maximum inverter frequency fh to a minimum inverter frequency fs to the switching elements 4 to 7 in response to And a minimum control winding current Ic1 for maximizing the inductance value L of the saturable reactor main winding Lm.
c, and the inverter / reactor switching signal S which goes to the H side when the inverter / reactor switching inversion signal Sth is High.
When t is High, the signal goes high to output the minimum control winding current Ic1, and when the inverter / reactor switching inversion signal Sth is low, the signal goes low to output the comparison operation signal ΔI. Control winding current switching circuit SW2
When the control winding current switching circuit SW2 is at the H side, the minimum control winding current Ic1 is changed to the saturable reactor control winding Lc.
And the control winding current switching circuit SW2 outputs L
The control winding current Ic in the range from the predetermined minimum control winding current Ic1 to the maximum control winding current Ic2 is output to the saturable reactor control winding Lc in accordance with the value of the comparison operation signal ΔI when the control operation is performed. This is a power supply device for arc machining comprising a constant / variable current output switching reactor control circuit 31.

The invention of the device according to claim 22 at the time of filing is an invention of a device for implementing the power supply control method according to the third embodiment, and as shown in FIG. 6, an inverter circuit INV comprising switching elements 4 to 7 as shown in FIG. To output switching element drive signals Tra to Trd to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage, and convert the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14. In the power supply device, a saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 between the inverter circuit INV and the main transformer 14, and an output current Io
, An output current setting unit 21 that outputs an output current setting signal Ir, an output current detector 19 that detects an output current Io and outputs an output current detection signal If, and the output current setting signal Ir and the output A comparison operation circuit 20 that performs a comparison operation on the current detection signal If to output a comparison operation signal ΔI = Ir−If; and a saturable reactor 26 in a high output current range when the set value of the output current setting signal Ir becomes large and becomes large. And the inverter-switching output current setting value Irv when switching from the control of the control winding current Ic to the control of the frequency (inverter frequency) f of the high-frequency AC pulse voltage is determined in advance. When the output current exceeds the set value Irv, the control of the control winding current Ic of the saturable reactor 26 is switched to the control of the inverter frequency f. A reactor / inverter switching reference signal setting circuit 33 for outputting a reactor / inverter switching reference signal Iv, and compares the reactor / inverter switching reference signal Iv with the output current setting signal Ir to output a reactor / inverter switching signal Sv. When the reactor / inverter switching signal Sv is Low, the reactor / inverter switching comparison circuit 32 outputs a switching element drive signal Tra having a predetermined maximum constant frequency fh.
To Trd are output to the switching elements 4 to 7, and when the reactor / inverter switching signal Sv is High, according to the value of the comparison operation signal ΔI = Ir−If,
A constant / variable frequency output switching element driving circuit for outputting switching element driving signals Tra to Trd having an inverter frequency f ranging from a predetermined maximum inverter frequency fh to a minimum inverter frequency fs to the switching elements 4 to 7; When the inverter switching signal Sv is Low, the comparison operation signal ΔI
The control winding current Ic corresponding to the value is output to the saturable reactor control winding Lc, and when the reactor-inverter switching signal Sv is High, the predetermined maximum control winding current Ic2 is changed to the saturable reactor control winding Lc. An arc machining power supply device including a constant / variable current output switching reactor control circuit 31 that outputs the current to Lc.

The invention according to claim 23 at the time of filing is an embodiment of the device according to claim 22 at the time of filing, and as shown in FIG. Switching element drive signal Tra
To Trd to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage, and convert the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14. The saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 connected between the inverter circuit INV and the main transformer 14 and the output current Io are set to output the output current setting signal Ir. And an output current detector 19 that detects an output current Io and outputs an output current detection signal If. The output current setting signal Ir and the output current detection signal If are compared and calculated. A comparison operation circuit 20 that outputs an operation signal ΔI = Ir−If; In the range, a reactor-inverter switching output current setting value Irv for switching from control of the control winding current Ic of the saturable reactor 26 to control of the frequency (inverter frequency) f of the high-frequency AC pulse voltage is predetermined, and the output current setting signal Ir Exceeds the reactor-inverter switching output current set value Irv, the reactor-inverter switching reference for outputting a reactor-inverter switching reference signal Iv for switching from control of the control winding current Ic of the saturable reactor 26 to control of the inverter frequency f. The signal setting circuit 33 compares the output current setting signal Ir with the reactor / inverter switching reference signal Iv,
When the output current setting signal Ir becomes the reactor / inverter switching reference signal Iv, the reactor / inverter switching signal Sv is switched from Low to High.
An inverter switching comparison circuit 32, a maximum inverter frequency signal generating circuit FH for generating a signal of the maximum inverter frequency fh for outputting the switching element driving signals Tra to Trd of the maximum inverter frequency fh, and the reactor inverter switching signal Sv When Low, the switching element drive signals Tra to Trd of the maximum inverter frequency fh are output to the switching elements 4 to 7, and the reactor / inverter switching signal Sv is set to High.
h, the switching element driving signals Tra to Trd having the inverter frequency f ranging from the predetermined maximum inverter frequency fh to the minimum inverter frequency fs are changed according to the value of the comparison operation signal ΔI = Ir−If. And the maximum control current Ic2 for minimizing the inductance value L of the saturable reactor main winding Lm to the saturable reactor control winding Lc. A maximum control winding current Ic2 to a predetermined maximum control winding current Ic2 according to the comparison operation signal ΔI value when the maximum control winding current generation circuit IC2 and the reactor / inverter switching signal Sv are Low. Is output to the saturable reactor control winding Lc. An arc machining power supply device including a constant / variable current output switching reactor control circuit 31 that outputs the maximum control winding current Ic2 when the torque / inverter switching signal Sv is High.

The invention of the device according to claim 24 at the time of filing is an embodiment of the device according to claim 23 at the time of filing, and as shown in FIG. Switching element drive signal Tra
To Trd to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage, and convert the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14. The saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 connected between the inverter circuit INV and the main transformer 14 and the output current Io are set to output the output current setting signal Ir. And an output current detector 19 that detects an output current Io and outputs an output current detection signal If. The output current setting signal Ir and the output current detection signal If are compared and calculated. A comparison operation circuit 20 that outputs an operation signal ΔI = Ir−If, and a saturable reset circuit that increases the set value of the output current setting signal Ir. The reactor-inverter switching output current setting value Irv for switching from control of the control winding current Ic of the reactor 26 to control of the frequency (inverter frequency) f of the high-frequency AC pulse voltage is determined in advance, and the output current setting signal Ir is set to the reactor current. When the inverter switching output current setting value Irv is exceeded, a reactor / inverter switching reference signal setting circuit 33 for outputting a reactor / inverter switching reference signal Iv for switching from control of the control winding current Ic of the saturable reactor 26 to control of the inverter frequency f.
And the output current setting signal Ir is compared with the reactor / inverter switching reference signal Iv.
When r becomes the reactor / inverter switching reference signal Iv, a reactor / inverter switching comparison circuit 32 that switches the reactor / inverter switching signal Sv from Low to High, and a reactor / inverter switching inversion signal Svh obtained by inverting the reactor / inverter switching signal Sv. A NOT circuit 37 for outputting, a maximum inverter frequency signal generating circuit FH for generating a signal of the maximum inverter frequency fh for outputting the switching element drive signals Tra to Trd of the maximum inverter frequency fh, and the reactor-inverter switching inversion signal Svh. Is high when is high
And an inverter frequency signal switching circuit SW1 that outputs a signal of the maximum inverter frequency fh, and outputs the comparison operation signal ΔI when the reactor-inverter switching inversion signal Svh is Low. When the frequency signal switching circuit SW1 is on the H side, the maximum inverter frequency fh is applied to the switching elements 4 to 7.
When the inverter frequency signal switching circuit SW1 is on the L side, a predetermined maximum inverter frequency fh to a minimum inverter frequency fs is determined according to the value of the comparison operation signal ΔI. The switching element drive signals Tra to Trd having the inverter frequency f in the range
Constant / variable frequency output switching switching element driving circuit 28 and the maximum control current Ic2 for minimizing the inductance value L of the saturable reactor main winding Lm to the saturable reactor control winding Lc. When the winding / current generating circuit IC2 and the reactor / inverter switching signal Sv are Low, the signal becomes the L side and the comparison operation signal ΔI
And a control winding current switching circuit SW2 that outputs the maximum control current Ic2 when the reactor-inverter switching signal Sv is High, and outputs a maximum control current Ic2. Receives the comparison operation signal ΔI and outputs a control winding current Ic in a range from a predetermined minimum control winding current Ic1 to a maximum control winding current Ic2 to the saturable reactor control winding Lc. When the control winding current switching circuit SW2 is on the H side, the maximum control winding current Ic2 is input and the constant / variable current output switching reactor control circuit 31 for minimizing the inductance value of the saturable reactor main winding Lm. It is a power supply device for arc processing provided.

The invention of the device according to claim 25 at the time of filing is an invention of a device for implementing the power supply control method according to the fourth embodiment. As shown in FIG. 8, the output of the DC power supply circuit DCP is changed to a high-frequency AC pulse. The saturable reactor Lm includes a saturable reactor resonant tank LCR formed by the resonant capacitor 12 and the saturable reactor 26 connected between the inverter circuit INV for converting to voltage and the main transformer 14.
Is maximized, and when the output current changes rapidly, the switching element drive signal T
An arc processing power supply device for controlling an output current Io by controlling an inverter frequency f of ra to Trd to increase or decrease an impedance value Z of a saturable reactor resonance tank LCR, comprising an inverter including switching elements 4 to 7 The switching element drive signals Tra to Trd are output to the circuit INV, the output of the DC power supply circuit DCP is converted into a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is converted by the main transformer 14 into a voltage suitable for arc machining. In the arc machining power supply device, a saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 connected between the inverter circuit INV and the main transformer 14 and an output current Io are set and output. An output current setting unit 21 that outputs a current setting signal Ir; An output current detector 19 that detects the force current Io and outputs an output current detection signal If, and compares the output current setting signal Ir with the output current detection signal If to calculate a comparison operation signal ΔI = Ir−If. A variable current output for outputting the control arithmetic circuit 20 for outputting the control winding current Ic of the saturable reactor 26 in accordance with the value of the comparison arithmetic signal ΔI to increase or decrease the inductance value L of the saturable reactor main winding Lm; A reactor control circuit 24, a load fluctuation detection calculation circuit 39 that outputs a load fluctuation detection signal Sf when the comparison operation signal ΔI that has been sequentially calculated suddenly changes and exceeds a predetermined fluctuation allowable value ΔIy, When the load change detection signal Sf is output, the comparison operation signal Δ
Switching element drive signals Tra to T according to the value of I
and a load dynamic switching element driving circuit 38 for controlling the inverter frequency f of the saturable reactor main winding Lm.
When the output current Io changes abruptly, the arc processing for controlling the output current Io by controlling the inverter frequency f of the switching element drive signals Tra to Trd to increase or decrease the impedance value Z of the saturable reactor resonance tank LCR. Power supply device.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention relates to the invention of the device of claim 24 at the time of filing, and as shown in FIG. To Trd to convert the output of the DC power supply circuit DCP into a high-frequency AC pulse voltage, and convert the high-frequency AC pulse voltage into a voltage suitable for arc processing by the main transformer 14. The saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 connected between the inverter circuit INV and the main transformer 14 and the output current Io are set to output the output current setting signal Ir. Output current setter 21 for detecting output current Io and output current detector 19 for detecting output current Io and outputting output current detection signal If A comparison operation circuit 20 that performs a comparison operation between the output current setting signal Ir and the output current detection signal If to output a comparison operation signal ΔI = Ir−If, and the set value of the output current setting signal Ir increases. The reactor-inverter switching output current setting value Irv for switching from control of the control winding current Ic of the saturable reactor 26 to control of the frequency (inverter frequency) f of the high-frequency AC pulse voltage is determined in advance. When the reactor / inverter switching output current setting value Irv is exceeded, the reactor for switching from control of the control winding current Ic of the saturable reactor 26 to control of the inverter frequency f is used.
Reactor / inverter switching reference signal setting circuit 33 for outputting inverter switching reference signal Iv, output current setting signal Ir and reactor / inverter switching reference signal Iv
When the output current setting signal Ir becomes the reactor / inverter switching reference signal Iv, the reactor / inverter switching comparison circuit 32 that switches the reactor / inverter switching signal Sv from Low to High, and the reactor / inverter switching signal Sv Inverted reactor
NOT circuit 3 that outputs inverter switching inversion signal Svh
7, a maximum inverter frequency signal generation circuit FH for generating a signal of the maximum inverter frequency fh for outputting the switching element drive signals Tra to Trd of the maximum inverter frequency fh, and when the reactor-inverter switching inversion signal Svh is High An inverter frequency signal switching circuit SW1 which outputs a signal of the maximum inverter frequency fh and outputs the comparison operation signal ΔI when the reactor-inverter switching inversion signal Svh is Low; When the inverter frequency signal switching circuit SW1 is at the H side, the switching element drive signals Tra to Trd of the maximum inverter frequency fh are output to the switching elements 4 to 7, and when the inverter frequency signal switching circuit SW1 is at the L side. According to the value of the comparison operation signal ΔI The switching element drive signals Tra to T having an inverter frequency f in a range from a predetermined maximum inverter frequency fh to a minimum inverter frequency fs.
A constant / variable frequency output switching element driving circuit 28 for outputting rd to the switching elements 4 to 7 and a maximum control current Ic2 for minimizing the inductance value L of the saturable reactor main winding Lm. Maximum control winding current generation circuit IC2 output to line Lc
When the reactor-inverter switching signal Sv is Low, the signal goes to the L side to output the comparison operation signal ΔI, and when the reactor-inverter switching signal Sv is High, H
And a control winding current switching circuit SW2 which outputs a maximum control current Ic2 when the control winding current switching circuit SW2 is on the L side. From the current Ic1 to the maximum control winding current Ic2
To the saturable reactor control winding Lc, and the control winding current switching circuit S
A power source for arc machining, comprising: a constant / variable current output switching reactor control circuit 31 that receives the maximum control winding current Ic2 when W2 is on the H side and minimizes the inductance value of the saturable reactor main winding Lm. Device.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A method and a power supply according to a first embodiment include a resonance capacitor 12 and a saturable reactor 2.
6 and the saturable reactor resonance tank LC
3, the output current Io is controlled by increasing or decreasing the inductance value L of the saturable reactor main winding Lm to increase or decrease the impedance value Z of the saturable reactor resonance tank LCR as shown in FIG. A power supply control method and a power supply device. Hereinafter, referring to the drawings, a saturable reactor 26 is used in place of the resonant reactor 13 of the conventional device, and a current value applied to the saturable reactor control winding Lc is controlled to control the saturable reactor main winding Lm. The method and the power supply according to the present invention for controlling the output current Io by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR by increasing or decreasing the inductance value L of the saturable reactor resonance tank LCR will be described.

FIG. 1 is a power supply unit connection diagram showing a first embodiment of a power supply unit for implementing the power supply control method for arc machining of the present invention. In FIG. 1, 1 to 21 perform the same operations as those of the conventional arc machining power supply device shown in FIG.

In FIG. 1, the constant frequency output switching element drive circuit 23 is provided with a start signal S of a start switch 27.
1 is input, the opposing first switching elements 4 and 5 and the opposing second switching elements 6 and 7
, A switching element drive signal Tr of one or more predetermined constant frequency inverter frequencies (hereinafter referred to as fixed inverter frequencies) fa, fb,.
a, Trb and switching element drive signals Trc, Tr
Supply d.

The constant frequency output switching element driving circuit 23 used in the present invention is a switching circuit in which the variable frequency output switching element driving circuit 23 of the prior art increases or decreases the inverter frequency f from the minimum inverter frequency fs to the maximum inverter frequency fh. While outputting the element drive signal, one or more predetermined constant frequency inverter frequencies fa, fb,... Having the same pulse width are output.
Is output.

The variable current output reactor control circuit 24
Comparison operation signal ΔI = Ir−If from comparison operation circuit 20
The control voltage is supplied to the saturable reactor 26 through the resistor 25 in response to The control winding current Ic is determined by the predetermined resistance value of the resistor 25 and the control voltage of the variable current output reactor control circuit 24.

When the control winding current Ic is input to the saturable reactor control winding Lc, the saturable reactor 26 has an inductance value L of the saturable reactor main winding Lm according to the value of the control winding current Ic. Can be controlled.

FIG. 2 is a diagram showing the inductance relationship of the saturable reactor main winding Lm. In FIG. 2, the control winding current Ic flowing through the saturable reactor control winding Lc is increased or decreased. When the control winding current Ic exceeds a predetermined minimum control winding current value Ic1, both legs of the core start magnetic saturation and the saturable reactor The inductance value L of the main winding Lm starts to decrease.

Further, as the control winding current Ic is increased or decreased, the inductance value L of the saturable reactor main winding Lm decreases in accordance with the increase or decrease of the control winding current Ic.
When the current exceeds the predetermined maximum control winding current value Ic2, both legs of the core are magnetically saturated, and the decrease in the inductance value L of the saturable reactor main winding Lm ends.

According to the present invention, as described above, the frequency of the switching element driving signal output from the constant frequency output switching element driving circuit 23 is one or a plurality of fixed inverter frequencies fa, fb,. By increasing or decreasing the current Ic from a predetermined minimum control winding current value Ic1 to a maximum control winding current value Ic2 and increasing or decreasing the inductance value L of the saturable reactor main winding Lm, the resonance capacitor 12 and the saturable reactor The output current Io of the arc machining power supply device is controlled by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR formed by 26.

FIG. 3 shows the impedance value Z and the control winding current Ic of the saturable reactor resonance tank LCR shown in FIG.
FIG. The horizontal axis is the inverter frequency f, and the vertical axis is the impedance value Z of the saturable reactor resonance tank LCR when the inverter frequency f is increased or decreased.
And the impedance value Z becomes minimum at the resonance frequency fr. A straight line parallel to the vertical axis represents an inverter frequency fa or f of a predetermined constant frequency having the same pulse width.
b, the control winding current I of the saturable reactor 26
The control range of the impedance value Z of the saturable reactor resonance tank LCR when c is increased or decreased from the minimum control winding current value Ic1 to the maximum control winding current value Ic2 is shown. When the control winding current Ic shown in FIG. 2 is a predetermined minimum control winding current value Ic1, the saturable reactor main winding Lm
Becomes maximum, and at this time, the impedance value Z of the saturable reactor resonance tank LCR shown in FIG. 3 also becomes maximum. As a result, the output current Io of the arc processing power supply device is minimized. Further, when the control winding current Ic is a predetermined maximum control winding current value Ic2, the inductance value L of the saturable reactor main winding Lm becomes minimum, and the impedance value Z of the saturable reactor resonance tank LVR shown in FIG. Is also minimized. As a result, the output current Io of the arc processing power supply device becomes maximum.

Since the two saturable reactor control windings Lc wound on both legs of the core of the saturable reactor 26 are connected in a direction in which the voltages cancel each other, the power output to the control winding current Ic is small. . Further, when a voltage is applied to the saturable reactor main winding Lm, a voltage proportional to the turn ratio between the saturable reactor main winding Lm and the saturable reactor control winding Lc is generated in the saturable reactor control winding Lc. However, since the voltages of the two saturable reactor control windings Lc wound on both legs of the core of the saturable reactor 26 are connected so as to cancel each other, an overvoltage may be applied to the variable current output reactor control circuit 24. There is no.

Next, referring to FIG. 3, the impedance value Z that can be adjusted by the reactor resonance tank LCF of the conventional power supply device described above with reference to FIG. 12 and the impedance value that can be adjusted by the saturable reactor resonance tank LCR used in the present invention. Compare with the impedance value Z. As shown in the prior art of FIG. 12, the dotted line shown in FIG. 12 indicates the impedance value adjustable by the saturable reactor resonance tank LCR when the inverter frequency f is increased or decreased from the minimum inverter frequency fs to the maximum inverter frequency fh. This indicates that the range is from Zs to Zh. On the other hand, the alternate long and short dash line indicates the inverter frequency fa having the same pulse width and the predetermined constant frequency in the first embodiment, and the control winding current Ic of the saturable reactor 26 is reduced to the minimum control winding current value Ic2. This indicates that the range of the impedance value that can be adjusted in the saturable reactor resonance tank LCR when it is increased or decreased from Za to Zb.

In the prior art, the reactor resonance tank LC
If the minimum inverter frequency fs is set too close to the resonance frequency fr in order to reduce the adjustable impedance value of F, the fluctuation of the impedance value Z becomes large and the fluctuation of the output current value Io becomes large. In addition, the maximum inverter frequency fh cannot be responded (followed) due to the characteristics of the switching element to be used, and the upper limit of the impedance value Z is limited, so that the output current Io cannot be reduced to a low current value. Therefore, in the related art, the adjustable impedance value range of the reactor resonance tank LCF is from Zs to Zh. On the other hand, according to the present invention, the inverter frequency fa of a predetermined constant frequency having the same pulse width to be used can be set to a frequency higher than the resonance frequency fr with a margin, and even if it is set lower than the maximum inverter frequency fh, The range of impedance values that can be adjusted in the saturable reactor resonance tank LCR when increasing or decreasing from the minimum control winding current value Ic1 to the maximum control winding current value Ic2 is from Za to Zb. Thus, as described above in the related art, the range of the adjustable impedance value of the reactor resonance tank LCF when the inverter frequency f is increased or decreased from the minimum inverter frequency fs to the maximum inverter frequency fh is from Zs to Zh. In comparison with the present invention, even if the inverter frequency fa of a predetermined constant frequency having the same pulse width to be used is set to a frequency higher than the resonance frequency fr or the minimum inverter frequency fs with a margin, the minimum control winding current value The range of the impedance value that can be adjusted in the saturable reactor resonance tank LCR when increasing or decreasing from Ic1 to the maximum control winding current value Ic2 is larger from Za to Zb.

When switching between the first fixed inverter frequency of the predetermined constant frequency inverter frequency fa having the same pulse width used in the present invention and the second fixed inverter frequency fb higher than the first fixed inverter frequency, The range of the impedance value that can be adjusted in the saturable reactor resonance tank LCR is changed from Zc to Zd, and the maximum output current value decreases, but the output current value at light load can be reduced.

[Second Embodiment] FIG. 4 is a power supply device connection diagram showing a second embodiment of a power supply device for implementing a power supply control method for arc machining. FIG. 5 is a relationship diagram for explaining the operation of the power supply device shown in FIG.

The method and the power supply of the second embodiment are shown in FIG.
As shown in the figure, the inverter circuit INV and the main transformer 1
4 and the resonance capacitor 12 and the saturable reactor 2
6 and the saturable reactor resonance tank LC
5, the impedance value Z of the saturable reactor resonance tank LCR is increased or decreased by increasing or decreasing the frequency (inverter frequency) f of the high-frequency AC pulse voltage converted by the inverter circuit INV in the low output current range as shown in FIG. To control the output current Io, and in a high output current range, increase or decrease the inductance value of the saturable reactor main winding Lm to thereby control the saturable reactor resonance tank LCR.
And a power supply device for controlling the output current Io by increasing or decreasing the impedance value Z of the power supply.

First, referring to FIG. 5, control of output current setting signal Ir, control winding current Ic applied to saturable reactor control winding Lc, inverter frequency f supplied to inverter circuit INV, and output current Io Will be described. In the second embodiment, an inverter / reactor switching output current setting value Ir when switching from control of the inverter frequency to control of the control winding current Ic of the saturable reactor 26 when the set value of the output current setting signal Ir becomes large.
When the output current setting signal Ir is the minimum output current setting value Ir1, the control winding current Ic of the saturable reactor 26 is set to the minimum control winding current Ic1 to set the saturable reactor main winding Lm. The inductance value L is maximized, and the inverter frequency f is changed to the maximum inverter frequency f.
h to maximize the impedance value Z of the saturable reactor resonance tank LCR,
The output current setting signal Ir is changed from the minimum output current setting value Ir1 to the inverter / reactor switching output current setting value Irt.
Up to the minimum control winding current Ic.
1, the inverter current f is increased or decreased in the range from the maximum inverter frequency fh to the minimum inverter frequency fs according to the output current setting signal Ir to increase or decrease the impedance value Z of the saturable reactor resonance tank LCR. Further, while the output current setting signal Ir is between the inverter / reactor switching output current setting value Irt and the maximum output current setting value Ir3, the inverter frequency f is maintained at the minimum inverter frequency fs and the output current setting signal Ir is maintained. The control winding current Ic of the saturable reactor 26 is reduced according to the increase / decrease of Ir.
Arc processing for controlling the output current Io by increasing or decreasing the inductance value L of the saturable reactor main winding Lm by increasing or decreasing from c1 to the maximum control winding current Ic2 and increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR. And a power supply device.

In the second embodiment, the minimum control winding current Ic1 is the control winding current Ic that maximizes the inductance value L of the saturable reactor main winding Lm, and the maximum control winding current Ic2 is the saturable reactor winding. A control winding current Ic that minimizes the inductance value L of the reactor main winding Lm,
The minimum inverter frequency fs is the saturable reactor main winding L
m is the frequency (inverter frequency) f of the high-frequency AC pulse voltage converted by the inverter circuit INV that minimizes the impedance value Z of the saturable reactor resonance tank LCR when the inductance value L of m is constant, and the maximum inverter frequency fh is Saturable reactor main winding Lm
Is the frequency (inverter frequency) f of the high-frequency AC pulse voltage converted by the inverter circuit INV that maximizes the impedance value Z of the saturable reactor resonance tank LCR when the inductance value L of the saturable reactor L is constant.

Hereinafter, the second embodiment will be described with reference to FIG. In the figure, the same reference numerals as those in FIG. 1 perform the same operations as those in FIG.

When the output current setting signal Ir exceeds a predetermined inverter / reactor switching output current setting value Irt, the inverter / reactor switching reference signal setting circuit 30 switches the saturable reactor 2 from the control of the inverter frequency f.
6. Inverter that switches to control of control winding current Ic
A reactor switching reference signal It is output. Inverter
The reactor switching comparison circuit 29 outputs the output current setting signal Ir
Is compared with inverter / reactor switching reference signal It to output inverter / reactor switching signal St.
The output current setting signal Ir is larger than the predetermined inverter / reactor switching output current setting value Irt shown in FIG.
When r> Irt), the inverter / reactor switching signal St is switched from Low to High.

First, control of the inverter frequency f of the constant / variable frequency output switching device driving circuit 28 will be described. The constant / variable frequency output switching switching element driving circuit 28 outputs a starting signal S of the starting switch 27.
1 while the switching element drive signal Tr is being input.
a to Trd are output to the inverter circuit INV. The minimum inverter frequency signal generation circuit FS generates a signal of the minimum inverter frequency fs for the constant / variable frequency output switching switching element drive circuit 28 to output the switching element drive signals Tra to Trd of the minimum inverter frequency fs. Inverter frequency signal switching circuit SW1
Goes low when the inverter / reactor switching signal St is low, outputs the comparison operation signal ΔI to the constant / variable frequency output switching switching element drive circuit 28, and outputs the inverter / reactor switching signal St to the high level.
At the time of h, it becomes H side, and outputs the signal of the minimum inverter frequency fs to the constant / variable frequency output switching device driving circuit 28.

With the above-described circuit, the constant / variable frequency output switching switching element drive circuit 28 causes the output current setting signal Ir to be smaller than the predetermined inverter / reactor switching output current setting value Irt shown in FIG. 5 (Ir <Irt). )
In the case of, the comparison operation signal ΔI is input from the inverter frequency signal switching circuit SW1, and the switching element driving in the range from the predetermined maximum inverter frequency fh to the minimum inverter frequency fs is determined according to the value of the comparison operation signal ΔI. When the output current setting signal Ir becomes larger than the inverter / reactor switching output current setting value Irt (Ir> Irt), the signal of the minimum inverter frequency fs is output from the inverter frequency signal switching circuit SW1. Input and the minimum inverter frequency fs
The switching element drive signals Tra to Trd are output.

Control winding current Ic of saturable reactor 26
Will be described. NOT circuit 36 outputs an inverter / reactor switching inversion signal Sth obtained by inverting inverter / reactor switching signal St. The constant / variable current output switching reactor control circuit 31 controls the control winding current I
c is output to the saturable reactor control winding Lc to increase or decrease the inductance value L of the saturable reactor main winding Lm. As shown in FIG. 5B, the minimum control winding current generation circuit IC1 uses a constant / variable current output switching reactor control circuit 31 to increase or decrease the impedance value Z of the saturable reactor resonance tank LCR. Line current Ic1
To the saturable reactor control winding Lc. The control winding current switching circuit SW2 goes to the H side when the inverter / reactor switching inversion signal Sth is High, and outputs the minimum control winding current Ic1 to the constant / variable current output switching reactor control circuit 31. When the inverter / reactor switching inversion signal Sth is Low, the signal goes to the L side, and the comparison operation signal ΔI is input to the constant / variable current output switching reactor control circuit 31.

With the above circuit, the constant / variable current output switching reactor control circuit 31 outputs the output current setting signal Ir.
Is smaller than the predetermined inverter / reactor switching output current set value Irt shown in FIG. 5 (Ir <Irt), the minimum control winding current Ic1 is input from the control winding current switching circuit SW2. The inductance value L of the saturated reactor main winding Lm is maximized to maximize the impedance value Z of the saturable reactor resonance tank LCR, and
When the output current setting value becomes larger than the inverter / reactor switching output current setting value Irt (Ir> Irt), the comparison operation signal ΔI is input from the control winding current switching circuit SW2, and is determined in advance according to the value of the comparison operation signal ΔI. The control winding current Ic in the range from the minimum control winding current Ic1 to the maximum control winding current Ic2 is output to the saturable reactor control winding Lc.

Next, the operation of the power supply according to the second embodiment shown in FIG. 4 will be described with reference to the relationship diagram of FIG. The second embodiment mainly performs control of the inductance value L of the saturable reactor main winding Lm, and when a low output current under light load is required, the inductance value L of the saturable reactor main winding Lm Is set to be maximum, the constant / variable frequency output switching switching element driving circuit 28 switches to the PFM method of controlling the inverter frequency f and outputs a small current.

FIG. 5A is a diagram showing the relationship between the control winding current Ic of the saturable reactor 26 and the output current setting signal Ir, and shows a saturable reactor main winding Lm with a predetermined minimum control winding current Ic1. Becomes maximum, and conversely, at a predetermined maximum control winding current Ic2, the inductance value L of the saturable reactor main winding Lm becomes minimum. The output current setting signal Ir is the minimum output current setting value Ir1
At this time, the control winding current Ic of the saturable reactor 26 is set to the minimum control winding current Ic1. Next, as shown in the range A, in the inverter frequency control range where the output current setting signal Ir is from the minimum output current setting value Ir1 to the inverter / reactor switching output current setting value Irt, the control winding current Ic is set to the minimum control winding current. The current is maintained at Ic1. Further, as shown in a range B, in the control winding current control range in which the output current setting signal Ir is from the inverter / reactor switching output current setting value Irt to the maximum output current setting value Ir3, the inverter frequency f is set to the minimum inverter frequency fs. And the control winding current Ic of the saturable reactor 26 is reduced to the minimum control winding current I in accordance with the increase or decrease of the output current setting signal Ir.
The current is increased or decreased from c1 to the maximum control winding current Ic2.

FIG. 5B shows a saturable reactor main winding L.
FIG. 4 is a diagram showing a relationship between the inductance value L of the output current setting signal Ir and the output current setting signal Ir.
Is maintained at the minimum control winding current Ic1, the inductance value L of the saturable reactor main winding Lm becomes the maximum. Further, as in the range B, in the control winding current control range, the minimum control winding current Ic1 to the maximum control winding current Ic
The inductance value L of the saturable reactor main winding Lm increases or decreases as the control winding current Ic in the range up to 2 increases or decreases.

FIG. 5C is a diagram showing the relationship between the inverter frequency f of the inverter circuit INV and the output current setting signal Ir. , The inverter frequency f is increased or decreased in the range from the maximum inverter frequency fh to the minimum inverter frequency fs. Further, as shown in the range B, the minimum inverter frequency fs is maintained in the control winding current control range.

FIG. 5D shows a relationship between the output current Io and the output current setting signal Ir. As shown in a range A, in the inverter frequency control range, the inverter frequency f The output current Io is controlled by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR. Further, as shown in the range B, in the control winding current control range,
The control winding current Ic of the saturable reactor 26 is increased or decreased according to the increase or decrease of the output current setting signal Ir to increase or decrease the inductance value L of the saturable reactor main winding Lm, and increase or decrease the impedance value Z of the saturable reactor resonance tank LCR. Thus, the output current Io is controlled.

The operation of FIG. 4 will be described below with reference to FIG. When the start signal S1 of the start switch 27 is input to the constant / variable frequency output switching device driving circuit 28, the operation starts. [1] Operation when output current setting signal Ir is smaller than inverter / reactor switching output current setting value Irt (Ir <Irt) Output current setting signal Ir is smaller than inverter / reactor switching output current setting value Irt (Ir In the case of <Irt), the inverter / reactor switching signal St output from the inverter / reactor switching comparison circuit 29 becomes Low, and the inverted inverter / reactor switching inverted signal Sth of the inverted signal becomes High. When the inverter / reactor switching inversion signal Sth becomes High, the control winding current switching circuit SW2 goes to the H side, and the minimum control winding current Ic1 output from the minimum control winding current generation circuit IC1 is kept constant.
It is input to the variable current output switching reactor control circuit 31.
This constant / variable current output switching reactor control circuit 31
Outputs the minimum control winding current Ic1 shown in FIG. 5 (A) to the saturable reactor control pure silver Lc, and changes the inductance value L of the saturable reactor to the maximum value Lh as shown in FIG. 5 (B). Keep it. The inductance value L is the maximum value L
h, when the inverter frequency f described later is the maximum inverter frequency fh, the saturable reactor resonance tank LCR
Has the maximum impedance value Z.

When Ir <Irt, the inverter / reactor switching signal St is low.
The inverter frequency signal switching circuit SW1 is on the L side, and outputs the comparison operation signal ΔI to the constant / variable frequency output switching device driving circuit. This comparison operation signal ΔI
The constant / variable frequency output switching switching element driving circuit 28 outputs switching element driving signals Tra to Trd in the range from the maximum inverter frequency fh to the minimum inverter frequency fs shown in FIG.
The impedance value Z of the saturable reactor resonance tank LCR increases or decreases, and as shown in FIG.
Control.

[2] The output current setting signal Ir is larger than the inverter / reactor switching output current setting value Irt (Ir
Operation when> Irt) When the output current setting signal Ir is larger than the inverter / reactor switching output current setting value Irt (Ir> Irt), the inverter / reactor switching signal output from the inverter / reactor switching comparison circuit 29 is output. St is High
, And the inverter / reactor switching inversion signal Sth of the inversion signal becomes Low. When the inverter / reactor switching signal St becomes High, the inverter frequency signal switching circuit SW1 goes high, and the minimum inverter frequency signal fs output from the minimum inverter frequency signal generating circuit FS is changed to a constant / variable frequency output switching switching element driving circuit 28. To enter. The constant / variable frequency output switching switching element driving circuit 28 outputs switching element driving signals Tra to Trd of the minimum inverter frequency signal fs shown in FIG. 5C to the inverter circuit INV,
The inductance value of the saturable reactor main winding Lm is maximized.

When Ir> Irt, since the inverter / reactor switching inversion signal Sth is Low, the control winding current switching circuit SW2 is on the L side, and the comparison operation signal ΔI is output as a constant / variable current output. It is input to the switching reactor control circuit 31. A constant / variable current output switching reactor control circuit 31 according to the value of the comparison operation signal ΔI
Outputs the control winding current Ic in a range from the minimum control winding current Ic1 to the maximum control winding current Ic2 shown in FIG. 5 (A), and outputs the saturable reactor as shown in FIG. 5 (B). As the inductance value L increases and decreases in the range from the maximum value Lh to the minimum value Ls, the impedance value Z of the saturable reactor resonance tank LCR increases and decreases, and the output current Io is controlled as shown in FIG.

[Third Embodiment] FIG. 6 is a power supply device connection diagram showing a third embodiment of a power supply device for implementing a power supply control method for arc machining. FIG. 7 is a relationship diagram for explaining the operation of the power supply device shown in FIG.

The third embodiment includes a saturable reactor resonance tank LCR formed by the resonance capacitor 12 and the saturable reactor 26 between the inverter circuit INV and the main transformer 14, as shown in FIG. In contrast to FIG. 5 described above, the output current Io is controlled by increasing or decreasing the inductance value of the saturable reactor main winding Lm and increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR in the low output current range. In the high output current range, the frequency (inverter frequency) f of the high-frequency AC pulse voltage is increased or decreased to increase the saturable reactor resonance tank LCR.
And a power supply device for controlling the output current Io by increasing or decreasing the impedance value Z of the power supply.

First, referring to FIG. 7, control of output current setting signal Ir, control winding current Ic applied to saturable reactor control winding Lc, inverter frequency f supplied to inverter circuit INV, and output current Io Will be described. In the third embodiment, a reactor-inverter control switching output current setting value Ir for switching from control of the control winding current Ic of the saturable reactor 26 to control f of the inverter frequency when the set value of the output current setting signal Ir becomes large.
v is determined in advance, and when the output current setting signal Ir is at the minimum output current setting value Ir1, the control winding current Ic of the saturable reactor 26 is set to the minimum control winding current Ic1 to set the saturable reactor main winding Lm. The inductance value L is maximized, and the inverter frequency f is changed to the maximum inverter frequency f.
h to maximize the impedance value Z of the saturable reactor resonance tank LCR,
When the output current setting signal Ir is between the minimum output current setting value Ir1 and the reactor / inverter switching output current setting value Irv, the inverter frequency f is changed to the maximum inverter frequency f.
h, the control winding current Ic of the saturable reactor 26 is increased or decreased from the minimum control winding current Ic1 to the maximum control winding current Ic2 in accordance with the increase or decrease of the output current setting signal Ir, and the impedance of the saturable reactor resonance tank LCR is increased. The output current Io is controlled by increasing or decreasing the value Z. Further, the output current setting signal Ir is changed from the reactor / inverter switching output current setting value Irv to the maximum output current setting value Ir3.
Up to the maximum control winding current Ic.
2, the inverter current f is increased or decreased in the range from the maximum inverter frequency fh to the minimum inverter frequency fs in accordance with the output current setting signal Ir to increase or decrease the impedance value Z of the saturable reactor resonance tank LCR. Power supply control method and power supply device for controlling arc processing.

In the third embodiment, the minimum control winding current Ic1 is the control winding current Ic that maximizes the inductance value L of the saturable reactor main winding Lm, and the maximum control winding current Ic2 is the saturable A control winding current Ic that minimizes the inductance value L of the reactor main winding Lm,
The minimum inverter frequency fs is the saturable reactor main winding L
m is the frequency (inverter frequency) f of the high-frequency AC pulse voltage converted by the inverter circuit INV that minimizes the impedance value Z of the saturable reactor resonance tank LCR when the inductance value L of m is constant, and the maximum inverter frequency fh is Saturable reactor main winding Lm
Is the frequency (inverter frequency) f of the high-frequency AC pulse voltage converted by the inverter circuit INV that maximizes the impedance value Z of the saturable reactor resonance tank LCR when the inductance value L of the saturable reactor L is constant.

Hereinafter, the third embodiment will be described with reference to FIG. 4, the same reference numerals as those in FIG. 4 perform the same operations as those in FIG.

When the output current setting signal Ir exceeds a predetermined reactor / inverter switching output current setting value Irv, the reactor / inverter switching reference signal setting circuit 33 determines from the control of the control winding current Ic of the saturable reactor 26 by the inverter. Reactor switching to control of frequency f
An inverter switching reference signal Iv is output. Reactor
The inverter switching comparison circuit 32 outputs the output current setting signal Ir
And a reactor / inverter switching reference signal Iv to output a reactor / inverter switching signal Sv.
The output current setting signal Ir is larger than the predetermined reactor-inverter switching output current setting value Irv shown in FIG.
When r> Irv), the reactor / inverter switching signal Sv is switched from Low to High.

First, control of the control winding current Ic of the saturable reactor 26 will be described. The constant / variable current output switching reactor control circuit 31 outputs the control winding current Ic to the saturable reactor control winding Lc to increase or decrease the inductance value L of the saturable reactor main winding Lm. As shown in FIG. 7 (B), the maximum control winding current generation circuit IC2 includes a constant / variable current output switching reactor control circuit 31 for controlling the inductance value L of the saturable reactor main winding Lm.
Is output to the saturable reactor control winding Lc. The control winding current switching circuit SW2 receives the reactor / inverter switching signal Sv
Goes low when the signal is low, outputs the comparison operation signal ΔI to the constant / variable current output switching reactor control circuit 31, and goes high when the reactor / inverter switching signal Sv is high. Maximum control winding current Ic
2 is output to the constant / variable current output switching reactor control circuit 31.

With the above circuit, the constant / variable current output switching reactor control circuit 31 outputs the output current setting signal Ir.
Is smaller than the predetermined reactor-inverter switching output current set value Irv shown in FIG. 7 (Ir <Irv), the predetermined minimum control winding current Ic1 to the maximum The control winding current Ic in the range up to the control winding current Ic2 is changed to the saturable reactor control winding Lc.
To increase or decrease the inductance value L of the saturable reactor main winding Lm from the maximum value to the minimum value, and the output current setting signal Ir is larger than the reactor / inverter switching output current setting value Irv (Ir> Irv). , The maximum control winding current Ic2 is input from the control winding current switching circuit SW2, and the inductance value L of the saturable reactor main winding Lm is maintained at a minimum.

Next, control of the inverter frequency f of the constant / variable frequency output switching switching element driving circuit 28 will be described. NOT circuit 37 outputs a reactor-inverter switching inversion signal Svh obtained by inverting reactor-inverter switching signal Sv. The constant / variable frequency output switching switching element drive circuit 28 includes a start switch 27.
The switching element drive signals Tra to Trd are output to the inverter circuit INV while the start signal S1 is input. The maximum inverter frequency signal generating circuit FH is a constant / variable frequency output switching switching element driving circuit 28.
Generates a signal of the maximum inverter frequency fh for outputting the switching element drive signals Tra to Trd of the maximum inverter frequency fh. The inverter frequency signal switching circuit SW1 receives the reactor / inverter switching signal Svh
Goes high when the signal is high, outputs a signal of the maximum inverter frequency fh to the constant / variable frequency output switching element driving circuit 28, and goes low when the reactor-inverter switching signal Svh is low. Become
The comparison operation signal ΔI is output to the constant / variable frequency output switching element driving circuit 28.

With the above-described circuit, the constant / variable frequency output switching switching element driving circuit 28 causes the output current setting signal Ir to be smaller than the predetermined reactor / inverter switching output current setting value Irv shown in FIG. 7 (Ir <Irv). )
In the case of, the signal of the maximum inverter frequency fh is input from the inverter frequency signal switching circuit SW1, and the switching element drive signals Tra to Trd of the maximum inverter frequency fh are output. The output current setting signal Ir is the reactor inverter switching output current. Larger than the set value Irv (Ir
> Irv), the inverter frequency signal switching circuit S
From W1 to a predetermined maximum inverter frequency fh to a minimum inverter frequency fs according to the value of the comparison operation signal ΔI.
Switching element drive signals Tra to Tr in the range up to
Output d.

Next, the operation of the power supply according to the third embodiment shown in FIG. 6 will be described with reference to the relationship diagram of FIG. In the third embodiment, the inverter frequency f is controlled mainly by the constant / variable frequency output switching switching element driving circuit 28, and when a low output current at light load is required, the saturable reactor main winding Lm After setting the inductance value L to be the maximum, the constant / variable frequency output switching switching element driving circuit 28 switches to the PFM method of controlling the inverter frequency f and outputs a small current.

FIG. 7A is a diagram showing the relationship between the control winding current Ic of the saturable reactor 26 and the output current setting signal Ir. The saturable reactor main winding Lm is controlled by a predetermined minimum control winding current Ic1. Becomes maximum, and the inductance value L of the saturable reactor main winding Lm becomes minimum at a predetermined maximum control winding current Ic2. In the figure, when the output current setting signal Ir is the minimum output current setting value Ir1, the control winding current Ic of the saturable reactor 26 is set to the minimum control winding current Ic1. Next, as shown in a range A, in the control winding current control range where the output current setting signal Ir is from the minimum output current setting value Ir1 to the reactor-inverter switching output current setting value Irv, the inverter frequency f is set to the maximum inverter frequency fh. Saturable reactor 2 according to the increase or decrease of the output current setting signal Ir.
6, the control winding current Ic is increased or decreased from the minimum control winding current Ic1 to the maximum control winding current Ic2. As shown in a range B, in the inverter frequency control range where the output current setting signal Ir is from the reactor / inverter switching output current setting value Irv to the maximum output current setting value Ir3, the control winding current Ic is set to the maximum control winding current. Maintain at Ic2.

FIG. 7B shows a relationship between the inverter frequency f of the inverter circuit INV and the output current setting signal Ir. In the same figure, as shown in a range A, the output current setting signal Ir is maintained at the maximum inverter frequency fh in the control winding current control range from the minimum output current setting value Ir1 to the reactor inverter switching output current setting value Irv. I do. Further, as shown in a range B, the output current setting signal I
r is the reactor-inverter switching output current set value Irv
In the inverter frequency control range from to the maximum output current setting value Ir3, the maximum inverter frequency fh to the minimum inverter frequency fs according to the increase or decrease of the output current setting signal Ir.
The inverter frequency f is increased or decreased in the range up to.

FIG. 7C shows the impedance value Z of the saturable reactor resonance tank LCR and the output current setting signal Ir.
In the control winding current control range, the inductance value L of the saturable reactor main winding Lm increases and decreases as the control winding current Ic increases and decreases, as shown in a range A. The impedance value Z of the LCR increases or decreases. Further, as in the range B, in the inverter frequency control range, the maximum inverter frequency fh to the minimum inverter frequency f
The impedance value Z of the saturable reactor resonance tank LCR is increased or decreased within the range up to s.

FIG. 7D shows a relation diagram between the output current Io and the output current setting signal Ir. As shown in a range A, in the control winding current control range, it is possible to increase or decrease the output current setting signal Ir. The output current Io is controlled by increasing or decreasing the control winding current Ic of the saturable reactor 26 to increase or decrease the inductance value L of the saturable reactor main winding Lm and increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR. I have. Further, as shown in a range B, in the inverter frequency control range, the output current Io is controlled by increasing and decreasing the inverter frequency f according to the increase and decrease of the output current setting signal Ir, and increasing and decreasing the impedance value Z of the saturable reactor resonance tank LCR. are doing.

The operation of FIG. 6 will be described below with reference to FIG. When the start signal S1 of the start switch 27 is input to the constant / variable frequency output switching device driving circuit 28, the operation starts. [1] Operation when output current setting signal Ir is smaller than reactor / inverter switching output current setting value Irv (Ir <Irv) Output current setting signal Ir is smaller than reactor / inverter switching output current setting value Irv (Ir In the case of <Irv), the reactor / inverter switching signal Sv output from the reactor / inverter switching comparison circuit 32 becomes Low, and the inverted reactor / inverter switching inverted signal Svh of the inverted signal becomes High. When the reactor / inverter switching inversion signal Svh becomes High, the inverter frequency signal switching circuit SW1 goes to the H side, and outputs a signal of the maximum inverter frequency fh to the constant / variable frequency output switching switching element drive circuit 28, and FIG. ), The impedance value Z of the saturable reactor resonance tank LCR is kept at a maximum. In addition, the above Ir <Ir
v, the reactor-inverter switching signal Sv is L
When it becomes ow, the control winding current switching circuit SW2 goes to the L side, and outputs the comparison operation signal ΔI to the constant / variable current output switching reactor control circuit 31. According to the value of the comparison operation signal ΔI, the constant / variable current output switching reactor control circuit 31 controls the control winding in the range from the minimum control winding current Ic1 to the maximum control winding current Ic2 shown in FIG. Current I
c is output to the saturable reactor 26, and the inductance value L of the saturable reactor main winding Lm is changed from 2πfsLh to 2
πfsLs to reduce the impedance value Z of the saturable reactor resonance tank LCR as shown in FIG.
Controls the output current Io by increasing or decreasing.

[2] The output current setting signal Ir is larger than the reactor / inverter switching output current setting value Irt (Ir
Operation when> Irv) When the output current setting signal Ir is larger than the reactor / inverter switching output current setting value Irv (Ir> Irv), the reactor / inverter switching signal Sv becomes High and the control winding current switching is performed. The circuit SW2 is turned to the H side, and the maximum control winding current Ic2 is input to the constant / variable current output switching reactor control circuit 31, and the saturable reactor main winding L
The inductance value L of m is maintained at the minimum value Ls. When Ir> Irv, the reactor / inverter switching inversion signal Svh becomes High, the inverter frequency signal switching circuit SW1 goes to the H side, and the comparison operation signal Δ
I is output to the constant / variable frequency output switching switching element drive circuit 28. According to the value of the comparison operation signal ΔI, the constant / variable frequency output switching switching element driving circuit 28 converts the range switching element driving signals Tra to Trd from the maximum inverter frequency fh to the minimum inverter frequency fs shown in FIG. The constant / variable frequency output switching is output to the switching element drive circuit 28,
As shown in FIG. 7C, the impedance value Z of the saturable reactor resonance tank LCR is increased or decreased according to the high frequency AC pulse voltage output from the variable frequency output switching device driving circuit 28, as shown in FIG. , And an output current Io.

Fourth Embodiment A method and a power supply according to a fourth embodiment are directed to a saturable reactor resonance tank L formed by the resonance capacitor 12 and the saturable reactor 26.
8, the output current Io is controlled mainly by controlling the inductance value L of the saturable reactor main winding Lm as shown in FIG. When necessary, the load-variable switching element driving circuit 38 switches to the PFM control method in which the inverter frequency f is controlled so that the saturable reactor resonance tank LCR can be followed by inductance control of the saturable reactor. A control method and a power supply device for controlling an output current Io by increasing and decreasing an impedance value Z. FIG. 8 is a power supply device connection diagram showing a fourth embodiment of the power supply device for performing the power supply control method for arc machining. In the figure, the same reference numerals as those in FIG.
Since the operation is the same as that described above, the description is omitted.

The method and the power supply of the fourth embodiment are shown in FIG.
And an output current setter 21 for setting an output current Io and outputting an output current setting signal Ir, as shown in FIG.
And an output current detector 19 that outputs an output current detection signal If, and compares the output current setting signal Ir with the output current detection signal If to perform a comparison operation signal ΔI = Ir
A comparison operation circuit 20 that outputs -If, a comparison operation signal Δ
A flame current output reactor control circuit 24 that outputs a control winding current Ic of the saturable reactor 26 according to the value of I to increase or decrease the inductance value L of the saturable reactor main winding Lm, and a comparison operation signal that is sequentially calculated A load fluctuation detection arithmetic circuit 39 that outputs a load fluctuation detection signal Sf when ΔI suddenly changes and exceeds a predetermined allowable fluctuation value ΔIy.
When the load variation detection signal Sf is output, the switching element drive signal T
and a load fluctuation switching device driving circuit 38 for controlling the inverter frequency f of the current saturable reactor Lm. The inductance value L of the saturable reactor main winding Lm is increased and decreased, and the switching is performed when the output current Io changes rapidly. The arc processing power supply device controls the inverter frequency f of the element drive signals Tra to Trd, and controls the output current Io by increasing or decreasing the impedance value Z of the saturable reactor resonance tank LCR.

In the method and the power supply according to the fourth embodiment, the minimum control winding current Ic1 is the control winding current Ic that maximizes the inductance value L of the saturable reactor main winding Lm.
c, the maximum control winding current Ic2 is the control winding current Ic that minimizes the inductance value L of the saturable reactor main winding Lm, and the fluctuation allowable lower limit inverter frequency ft is the inductance of the saturable reactor main winding Lm. Saturable reactor resonance tank LC when value L is a value under control
Inverter circuit I that minimizes the impedance value Z of R
The saturable reactor resonance tank is a frequency (inverter frequency) f of a high-frequency AC pulse voltage converted by NV, and the allowable maximum inverter frequency fk is the inductance value L of the saturable reactor main winding Lm under control. The frequency (inverter frequency) f of the high-frequency AC pulse voltage converted by the inverter circuit INV that maximizes the impedance value Z of the LCR.

In FIG. 8, when a sudden load change occurs, the comparison operation signal ΔI = Ir−If of the difference between the output current setting signal Ir and the output current detection signal If sharply increases.
The load fluctuation detection calculation circuit 39 calculates the comparison calculation signal ΔI = Ir
-If, the comparison operation signal ΔI
Is compared with a predetermined allowable variation value ΔIy, and ΔI> Δ
In the case of Iy, the output signal Sf of the load fluctuation detection arithmetic circuit 39
To High. When the load change detection signal Sf is Low, the load change switching switching element drive circuit 38
The inverter frequency f is set to a predetermined constant frequency ft,
When the load fluctuation detection signal Sf is High, the value of the inverter frequency f is controlled according to the value of the comparison operation signal ΔI = Ir−If.

FIG. 9 is a relationship diagram for explaining the operation of the power supply device shown in FIG. The operation of the embodiment of the power supply device shown in FIG. 8 will be described with reference to the relationship diagram of FIG. In the fourth embodiment, the output current is controlled mainly by controlling the inductance value of the saturable reactor 26 main winding Lm. If you can not follow by control,
The value of the inverter frequency f is controlled by the load change switching device driving circuit 38.

FIG. 9A shows the inverter frequency f of the saturable reactor inverter INVR and the output current setting signal I.
9 (A), the impedance value Z of the saturable reactor resonance tank LCR is maximized at a predetermined fluctuation allowable upper limit inverter frequency fk, and a predetermined fluctuation allowable lower limit inverter frequency is set as shown in FIG. ft is the impedance value Z of the saturable reactor resonance tank LCR
To a minimum. FIG. 9B shows a relationship diagram between the control winding current Ic of the saturable reactor 26 and the output current setting signal Ir, and maximizes the inductance value of the saturable reactor 26 with a predetermined minimum control winding current Ic1. Saturable reactor main winding Lm at a predetermined maximum control winding current Ic2.
Is minimized.

When a sudden load change occurs during the arc welding, the value of the output signal ΔI = Ir−If of the comparison operation circuit 20 changes rapidly. When the comparison operation signal ΔI = Ir−If is input to the load fluctuation detection operation circuit 39, the load fluctuation detection operation circuit 39 sequentially calculates the value of the comparison operation signal ΔI = Ir−If, and the comparison operation signal ΔI = Ir− When If exceeds a predetermined fluctuation allowable value ΔIy, the load fluctuation detection arithmetic circuit 39 sets the load fluctuation detection signal Sf of the output signal to High. When the output signal Sf is High, the load fluctuation switching device driving circuit 38 outputs the comparison operation signal ΔI
The value of the predetermined fixed inverter frequency fa is changed according to the value of the switching element drive frequency in the range from the predetermined allowable upper limit inverter frequency fk to the allowable lower limit inverter frequency ft as shown in FIG. Signal T
The signals ra to Trd are output to the load change switching device driving circuit 38 to quickly respond to a sudden load change.

[0099]

According to the prior art, the inverter frequency f must be increased or decreased from the minimum inverter frequency fs for outputting the high output current Io to the maximum inverter frequency fh for outputting the low output current Io. Must. Therefore, in the related art, in order to lower the minimum inverter frequency fs, the main transformer and the DC reactor cannot be sufficiently reduced in size. On the other hand, in the first embodiment of the present invention, as shown in FIG. 3, the inverter frequency f of the saturable reactor inverter INVR is
Is fixed to a predetermined appropriate fixed inverter frequency fa having a sufficient margin more than the resonance frequency fr, the frequency becomes higher than the minimum inverter frequency fs of the prior art, so that the main transformer and the DC reactor are smaller than the conventional device. Can be

In the case where a snubber circuit for absorbing surge voltage is provided in the switching element and the diode of the inverter circuit, in the prior art, the switching loss becomes large in order to increase the maximum inverter frequency fh. And a large snubber circuit is required. On the other hand, in the first embodiment of the present invention, the inverter frequency can be set to an inverter frequency fa lower than the maximum inverter frequency fh of the related art, so that switching is not performed near the active region of the switching element. As a result, the loss of the snubber circuit is reduced, and the size of the snubber circuit can be reduced.

Further, in the prior art, as shown in FIG. 3, when the inverter frequency f from the minimum inverter frequency fs to the maximum inverter frequency fh is increased or decreased, the adjustable impedance value range of the reactor resonance tank LCF is limited. Zs to Zh. On the other hand, in the first embodiment of the present invention, even if the fixed inverter frequency fa is set to a frequency higher than the minimum inverter frequency fs of the related art with a margin, the fixed inverter frequency fa is increased from the minimum control winding current value Ic1 of the saturable reactor. The range of the adjustable impedance value (Za to Zb) of the saturable reactor resonance tank LCR when the control winding current value is increased or decreased to the control winding current value Ic2 is the range of the adjustable impedance value (Zs to Zh) of the conventional technology. Can be wider than.

In the first embodiment of the present invention, the first fixed inverter frequency fa and the second fixed inverter frequency fb higher than the first fixed inverter frequency fa are set.
To increase or decrease the impedance value Z of the saturable reactor resonance tank LCR, thereby making the output current I
When o is controlled, as shown in FIG. 3, the range of the impedance value adjustable in the saturable reactor resonance tank LCR is switched from Za to Zb, Zc, and Zd.
When the maximum output current value is the first fixed inverter frequency fa, the range of the impedance value is determined by Za, and when the load is light, the low output current value is the second fixed inverter frequency f
At b, the range of the impedance value is determined by Zd, so that the maximum output current value can be increased or the low output current value at light load can be reduced as compared with the prior art.

[2] Effects of the Invention of the Second Embodiment The invention of the second embodiment mainly employs a method of increasing or decreasing the inductance value L of the saturable reactor, and the small value that cannot be sufficiently controlled by the reactor value L of the saturable reactor. Since the control of the current region is switched to the PFM method, the inverter frequency can be kept constant in most output current regions, so that the size of the snubber circuit and the size of the main transformer and the DC reactor can be reduced.

[3] Effect of the Invention of the Third Embodiment The invention of the third embodiment mainly performs a method of controlling the inverter frequency of the resonance type inverter circuit, and the small current at the time of light load that cannot be sufficiently controlled by the inverter frequency. Since the control of the area is switched to a method of increasing or decreasing the inductance value L of the saturable reactor, it is effective when a wide range of load control is required.

[4] Effects of the Invention of the Fourth Embodiment The invention of the fourth embodiment mainly performs a method of increasing or decreasing the inductance value L of the saturable reactor, and a sudden load change always occurs, resulting in excessive control. Since the switching to the PFM system is detected by detecting the case where the response is delayed, the miniaturization of the snubber circuit and the miniaturization of the main transformer and the DC reactor can be realized.

[Brief description of the drawings]

FIG. 1 is a power supply device connection diagram showing a first embodiment of a power supply device for performing an arc processing power supply control method of the present invention.

FIG. 2 is a diagram illustrating an inductance relationship of a saturable reactor.

FIG. 3 is a saturable reactor resonance tank LCR shown in FIG. 1;
FIG. 6 is a diagram showing a relationship between the impedance of the control winding and the control winding current Ic.

FIG. 4 is a power supply device connection diagram showing a second embodiment of the power supply device for performing the power supply control method for arc machining.

5 shows a relationship diagram between an inductance value L of the saturable reactor Lm shown in FIG. 4 and a control winding current Ic and a relationship diagram of an inverter frequency.

FIG. 6 is a power supply device connection diagram showing a third embodiment of the power supply device for implementing the power supply control method for arc machining.

7 is a saturable reactor resonance tank LCR shown in FIG. 6;
And a relationship diagram of the control winding current Ic.

FIG. 8 is a power supply device connection diagram showing a fourth embodiment of the power supply device for performing the power supply control method for arc machining.

9 shows a relationship diagram of an inverter frequency and a relationship diagram of a control winding current Ic shown in FIG.

FIG. 10 is a power supply device connection diagram of a conventional power supply device for arc machining using a resonance type circuit.

11 is a timing chart of a switching element drive signal output from the variable frequency output switching element drive circuit shown in FIG.

12 is a diagram showing a relationship between the impedance of the reactor resonance tank LCF shown in FIG. 10 and the inverter frequency.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Three-phase AC commercial power supply 2 Primary rectifier circuit 3 Smoothing capacitor 4 Switching element 5 Switching element 6 Switching element 7 Switching element 8 Diode 9 Diode 10 Diode 11 Diode 12 Resonant capacitor 13 Resonant reactor 14 Main transformer 15 Secondary rectifier circuit 16 DC Reactor 17 Non-consumable electrode 18 Workpiece 19 Output current detector 20 Comparison operation circuit 21 Output current setting unit 22 Variable frequency output switching element drive circuit 23 Constant frequency output switching element drive circuit 24 Variable current output reactor control circuit 25 Resistor 26 Saturable reactor 27 Start switch 28 Constant / variable frequency output switching switching element drive circuit 29 Inverter / reactor switching comparison circuit 30 Inverter / reactor switching reference signal Constant circuit 31 Constant / variable current output switching reactor control circuit 32 Reactor / inverter switching comparison circuit 33 Reactor / inverter switching reference signal setting circuit 36 NOT circuit 37 NOT circuit 38 Load variation switching switching element drive circuit 39 Load variation detection calculation circuit DCP DC Power supply circuit FS Minimum inverter frequency signal generation circuit FH Maximum inverter frequency signal generation circuit IC1 Minimum control winding current generation circuit IC2 Maximum control winding current generation circuit INV Inverter circuit INVF Resonance reactor inverter INVR Saturable reactor inverter LCF Reactor resonance tank LCR Possible Saturated reactor resonance tank SW1 Inverter frequency signal switching circuit SW2 Control winding current switching circuit f Inverter frequency fa First fixed inverter frequency fb Second Fixed inverter frequency fh Maximum inverter frequency fk Fluctuation allowable upper limit inverter frequency fr Resonance frequency fs Minimum inverter frequency ft Fluctuation allowable lower limit inverter frequency Ic Control winding current value Ic1 Minimum control winding current Ic2 Maximum control winding current If Output current detection signal Io Output current Ir Output current setting signal Ir1 Minimum output current setting Ir3 Maximum output current setting Irt Inverter / reactor switching output current setting Irv Reactor / inverter switching output current setting Itt Inverter / reactor switching reference signal Iv Reactor / inverter switching reference Signal L Inductance value Lc Saturable reactor control winding Lm Saturable reactor main winding Lh Maximum value of inductance of saturable reactor Ls Maximum value of inductance of saturable reactor Small value Sth Inverter / reactor switching inversion signal Sv Reactor / inverter switching signal Svh Reactor / inverter switching inversion signal St Inverter / reactor switching signal Sv Reactor / inverter switching signal Sf Load fluctuation detection signal Tra Switching element driving signal Trb Switching element driving signal Trc Switching element drive signal Trd Switching element drive signal X Reactance value Z Impedance value of saturable reactor or reactor resonance tank ΔI Comparison calculation signal ΔIy Allowable fluctuation value

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Nakai 2-1-11, Tagawa, Yodogawa-ku, Osaka-shi Inside Daihen Corporation (72) Inventor Ichiro Umezawa 2-1-1, Tagawa, Yodogawa-ku, Osaka-shi Stock Association F-term in DAIHEN Co., Ltd. (reference) 4E082 BA01 CA01 DA01 EA03 EB11 EC13 EE03 EE04 EE05 EE08 EF14 EF30 FA01 FA04 5H007 AA00 AA07 BB00 CA02 CB02 CB05 CB22 CC01 CC32 DA03 DA05 DC02 5H730 AS12 BB27 CC03 DD16 DD16 DD16 DD16 DD16 DD16 DD16 DD16 DD16 DD16 DD16

Claims (25)

[Claims] 1. A power supply control method comprising a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor, and controlling an output current by increasing or decreasing an impedance value of the saturable reactor resonance tank. A switching element drive signal is output to an inverter circuit composed of a switching element, and an output of the DC power supply circuit is converted into a high frequency AC pulse voltage by an inverter circuit composed of the switching element, and the high frequency AC pulse voltage is subjected to arc machining by a main transformer. In the arc machining power supply control method of converting to a suitable voltage, a switching element drive signal of a predetermined fixed inverter frequency with the same pulse width is output to the switching element, and the output of the DC power supply circuit is converted to a high-frequency AC pulse voltage. Convert the inverter circuit A saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor is connected between the main transformer and the main transformer to increase or decrease the control winding current of the saturable reactor and increase or decrease the inductance value of the main winding. A power supply control method for arc machining in which an output current is controlled by increasing or decreasing an impedance value of a saturable reactor resonance tank. 2. The method according to claim 1, wherein a control winding current of said saturable reactor is increased or decreased according to a value of a comparison operation signal obtained by comparing an output current setting signal and an output current detection signal. A power supply control method for controlling an output current by increasing or decreasing a value, comprising: outputting a switching element drive signal to an inverter circuit including a switching element; and outputting an output of a DC power supply circuit to a high frequency AC pulse by an inverter circuit including the switching element. In a power supply control method for arc machining, which converts the high-frequency AC pulse voltage into a voltage suitable for arc machining by a main transformer, the switching element drive signal having a predetermined fixed inverter frequency with the same pulse width is used. Output to the switching element and the output of the DC power supply And converting the output current setting signal to the output current detection signal by connecting a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor between the inverter circuit and the main transformer. The output current is controlled by increasing or decreasing the control winding current of the saturable reactor and increasing or decreasing the inductance value of the main winding to increase or decrease the impedance value of the saturable reactor resonance tank according to the value of the comparison operation signal obtained. Power control method for arc machining. 3. The method according to claim 1, wherein the switching element drive signal having the same pulse width and a predetermined fixed inverter frequency is replaced with a first fixed inverter frequency predetermined with the same pulse width and the first fixed inverter frequency. High second
A power supply control method for controlling an output current by increasing or decreasing an impedance value of a saturable reactor resonance tank using a switching element drive signal switched to a fixed inverter frequency, wherein the switching element is connected to an inverter circuit including the switching element. A drive signal is output, and the output of the DC power supply circuit is converted into a high-frequency AC pulse voltage by an inverter circuit including a switching element.
In the arc machining power supply control method for converting the high-frequency AC pulse voltage into a voltage suitable for arc machining by a main transformer, a first fixed inverter frequency predetermined with the same pulse width and the first fixed inverter frequency are used. Switching to a higher second fixed inverter frequency to output a switching element drive signal to the switching element,
The output of the DC power supply circuit is converted to a high-frequency AC pulse voltage,
A saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor is connected between the inverter circuit and the main transformer, and the control winding current of the saturable reactor is increased or decreased to increase the inductance value of the main winding. A power supply control method for arc machining in which the output current is controlled by increasing or decreasing the impedance value of the saturable reactor resonance tank. 4. An output current is controlled in a low output current range by increasing or decreasing an inverter frequency of a high-frequency AC pulse voltage converted by an inverter circuit to increase or decrease an impedance value of a saturable reactor resonance tank, and in a high output current range. A power supply control method for controlling an output current by increasing or decreasing an inductance value of a saturable reactor main winding and increasing or decreasing an impedance value of a saturable reactor resonance tank, wherein a switching element drive signal is supplied to an inverter circuit including a switching element. Output, and the output of the DC power supply circuit is converted into a high-frequency AC pulse voltage by an inverter circuit including a switching element,
In the arc machining power supply control method for converting the high-frequency AC pulse voltage into a voltage suitable for arc machining by a main transformer, the arc transformer power supply control method may include a resonance capacitor and a saturable reactor formed between the inverter circuit and the main transformer. Connect a saturable reactor resonance tank and control the output current by increasing or decreasing the inverter frequency of the high-frequency AC pulse voltage converted by the inverter circuit in a predetermined low output current range to increase or decrease the impedance value of the saturable reactor resonance tank Arc processing for controlling the output current by increasing or decreasing the inductance value of the saturable reactor main winding and increasing or decreasing the impedance value of the saturable reactor resonance tank in the high output current range exceeding the predetermined low output current range. Power supply control method. 5. A switching element drive signal is output to an inverter circuit composed of a switching element, and an output of a DC power supply circuit is converted into a high frequency AC pulse voltage by an inverter circuit composed of a switching element. In a power supply control method for arc processing for converting to a voltage suitable for arc processing by a heater, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor is connected between an inverter circuit and the main transformer, Inverter / reactor switching for switching from control of the inverter frequency of the high-frequency AC pulse voltage to control of the saturable reactor control winding current The output current set value is determined in advance. Control winding current to the minimum control winding current. At the same time, the inverter frequency is set to the maximum inverter frequency. Next, while the output current setting signal is between the minimum output current set value and the inverter / reactor switching output current set value, the control winding current is set to the minimum control winding. The output current is controlled by maintaining the current and increasing or decreasing the inverter frequency in the range from the maximum inverter frequency to the minimum inverter frequency in accordance with the increase or decrease of the output current setting signal. Between the current setting value and the maximum output current setting value, the inverter frequency is maintained at the minimum inverter frequency, and the control winding current of the saturable reactor is changed from the minimum control winding current to the maximum control winding according to the increase or decrease of the output current setting signal. Increase or decrease the current to increase or decrease the inductance value of the saturable reactor main winding. Arc machining power supply control method for controlling the output current by increasing or decreasing the impedance value of the reactor resonant tank. 6. An arc processing power supply control for converting an output of a DC power supply circuit into a high frequency AC pulse voltage by an inverter circuit including a switching element, and converting the high frequency AC pulse voltage into a voltage suitable for arc processing by a main transformer. The method further comprises connecting a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor between the inverter circuit and the main transformer, so that a set value of an output current setting signal increases and a high-frequency AC pulse The inverter / reactor switching output current set value when switching from control of the voltage inverter frequency to control of the saturable reactor control winding current is determined in advance, and the saturable reactor is set when the output current setting signal is at the minimum output current set value. The control winding current of the saturable reactor main winding is set to the minimum control winding current. The inductance value of the saturable reactor resonance tank is maximized by setting the inverter frequency to the maximum inverter frequency while maximizing the conductance value, and then, the output current setting signal is changed from the minimum output current setting value to the inverter current. Until the reactor switching output current set value, the control winding current is maintained at the minimum control winding current, and the inverter frequency is increased or decreased in the range from the maximum inverter frequency to the minimum inverter frequency according to the increase or decrease of the output current setting signal. The output current is controlled by increasing or decreasing the impedance value of the saturable reactor resonance tank.Furthermore, while the output current setting signal is from the inverter / reactor switching output current setting value to the maximum output current setting value, the inverter frequency is minimized. The output current setting signal is maintained while maintaining the inverter frequency. The control winding current of the saturable reactor is increased or decreased from the minimum control winding current to the maximum control winding current according to the increase or decrease of the saturable reactor. A power supply control method for arc machining in which an output current is controlled by causing the power supply to be controlled. 7. An arc machining power supply control for converting an output of a DC power supply circuit into a high frequency AC pulse voltage by an inverter circuit including a switching element, and converting the high frequency AC pulse voltage into a voltage suitable for arc processing by a main transformer. The method further comprises connecting a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor between the inverter circuit and the main transformer, so that a set value of an output current setting signal is increased to increase a high output current. In the range, an inverter / reactor switching output current set value for switching from control of the inverter frequency of the high-frequency AC pulse voltage to control of the control winding current of the saturable reactor is predetermined, and the output current setting signal is the inverter / reactor switching output current. When the value is smaller than the set value, the minimum control winding current is And the control winding current is maintained at the minimum control winding current to maximize the inductance value of the saturable reactor main winding and to compare the output current setting signal with the output current detection signal. A switching element drive signal in a range from a predetermined maximum inverter frequency to a predetermined minimum inverter frequency is supplied to the switching element in accordance with the value of the operation signal ΔI, thereby increasing or decreasing the impedance value of the saturable reactor resonance tank. Next, when the output current becomes larger than the inverter / reactor switching output current set value, the switching element drive signal of the minimum inverter frequency is supplied to the switching element to maintain the inverter frequency at the minimum inverter frequency and to perform the comparison. Maximum control from a predetermined minimum control winding current according to the value of the operation signal ΔI Control the output current by passing the winding current to the saturable reactor and increasing or decreasing the inductance value of the saturable reactor main winding to increase or decrease the impedance value of the saturable reactor resonance tank. Power control method for arc machining. 8. An arc processing power supply control for converting an output of a DC power supply circuit into a high frequency AC pulse voltage by an inverter circuit including a switching element, and converting the high frequency AC pulse voltage into a voltage suitable for arc processing by a main transformer. The method further comprises connecting a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor between the inverter circuit and the main transformer, so that a set value of an output current setting signal is increased to increase a high output current. In the range, an inverter / reactor switching output current set value for switching from control of the inverter frequency of the high-frequency AC pulse voltage to control of the control winding current of the saturable reactor is predetermined, and the output current setting signal is the inverter / reactor switching output current. If the set value is exceeded, the saturable reactor An inverter / reactor switching reference signal for switching to control of the control winding current of the motor, and comparing the output current setting signal with the inverter / reactor switching reference signal. If it is smaller, the inverter / reactor switching signal becomes low, the minimum control winding current is supplied to the saturable reactor, and the control winding current is maintained at the minimum control winding current. In addition to maximizing the inductance value of the main winding, switching between a predetermined maximum inverter frequency and a minimum inverter frequency is performed in accordance with the value of the comparison operation signal obtained by comparing the output current setting signal and the output current detection signal. An element drive signal is supplied to the switching element to increase the impedance value of the saturable reactor resonance tank. Controlling the output current by, then, when the output current setting signal becomes larger than the inverter reactor switching reference signal, the inverter reactor switching signal is High
Then, the switching element drive signal of the minimum inverter frequency is supplied to the switching element to maintain the inverter frequency at the minimum inverter frequency, and according to the value of the comparison operation signal, from the predetermined minimum control winding current. Output current is obtained by supplying control winding current in the range up to the maximum control winding current to the saturable reactor, increasing or decreasing the inductance value of the saturable reactor main winding and increasing or decreasing the impedance value of the saturable reactor resonance tank. Power control method for arc processing to control the power. 9. An output current is controlled by increasing or decreasing an inductance value of a saturable reactor main winding in a low output current range and increasing or decreasing an impedance value of a saturable reactor resonance tank. A power supply control method for controlling an output current by increasing or decreasing an inverter frequency of a voltage to increase or decrease an impedance value of a saturable reactor resonance tank. An arc processing power supply control method for converting an output of a power supply circuit into a high-frequency AC pulse voltage by an inverter circuit including a switching element and converting the high-frequency AC pulse voltage into a voltage suitable for arc processing by a main transformer. And the main transformer A saturable reactor resonance tank formed by a vibration capacitor and a saturable reactor is connected, and in a predetermined low output current range, the inductance value of the saturable reactor main winding is increased or decreased to reduce the impedance value of the saturable reactor resonance tank. The output current is controlled by increasing or decreasing, and in the high output current range exceeding the predetermined low output current range, the impedance value of the saturable reactor resonance tank is increased or decreased by increasing or decreasing the inverter frequency of the high-frequency AC pulse voltage converted by the inverter circuit. A power supply control method for arc machining in which the output current is controlled by increasing or decreasing. 10. The output current is controlled by increasing / decreasing an inductance value of a saturable reactor main winding in a low output current range and increasing / decreasing an impedance value Z of a saturable reactor resonance tank. An arc processing power supply control method for controlling an output current by increasing or decreasing an impedance value of a saturable reactor resonance tank by increasing or decreasing an inverter frequency of a pulse voltage, and outputting a switching element drive signal to an inverter circuit including a switching element. And an arc processing power supply control method for converting the output of the DC power supply circuit to a high frequency AC pulse voltage by an inverter circuit including a switching element and converting the high frequency AC pulse voltage to a voltage suitable for arc processing by a main transformer. , The inverter circuit and the main A saturable reactor resonant tank formed by a resonant capacitor and a saturable reactor is connected between the transformer and the reactor to switch from controlling the inverter frequency of the high-frequency AC pulse voltage to controlling the control winding current of the saturable reactor. The inverter switching output current set value is determined in advance, and when the output current setting signal is the minimum output current set value, the control winding current of the saturable reactor is set to the minimum control winding current, and the inverter frequency is set to the maximum inverter frequency. Then, when the output current setting signal is between the minimum output current setting value and the reactor / inverter switching output current setting value, the inverter frequency is maintained at the maximum inverter frequency, and the output current setting signal is increased or decreased. The control winding current of the saturation reactor is from the minimum control winding current to the maximum control winding current. The control winding current is maintained at the maximum control winding current while the output current setting signal is between the reactor-inverter switching output current setting value and the maximum output current setting value. A power supply control method for arc machining, wherein the output current is controlled by increasing or decreasing the inverter frequency in the range from the maximum inverter frequency to the minimum inverter frequency according to the increase or decrease of the output current setting signal. 11. A switching element drive signal is output to an inverter circuit including a switching element, and an output of a DC power supply circuit is converted into a high frequency AC pulse voltage by an inverter circuit including a switching element. In the arc machining power supply control method for converting into a voltage suitable for arc machining by a heater, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor is connected between the inverter circuit and the main transformer. The reactor / inverter switching output current set value for switching from control of the saturable reactor control winding current to control of the inverter frequency of the high-frequency AC pulse voltage is determined in advance, and the output current setting signal is set to the minimum output current set value. The control winding current of the saturation reactor is the minimum control winding current. To maximize the inductance value of the saturable reactor main winding, and set the inverter frequency to the maximum inverter frequency to maximize the impedance value of the saturable reactor resonance tank. While the signal is between the minimum output current setting value and the reactor / inverter switching output current setting value, the inverter frequency is maintained at the maximum inverter frequency, and the control winding current of the saturable reactor is minimized according to the increase or decrease of the output current setting signal. The output current is controlled by increasing / decreasing the impedance value of the saturable reactor resonance tank by increasing / decreasing from the winding current to the maximum control winding current.
Between the inverter switching output current setting value and the maximum output current setting value, the control winding current is maintained at the maximum control winding current, and the inverter frequency is changed from the maximum inverter frequency to the minimum inverter frequency according to the increase or decrease of the output current setting signal. The power supply control method for an arc machining, wherein the output current is controlled by increasing or decreasing the impedance value Z of the saturable reactor resonance tank by increasing or decreasing the range of the impedance. 12. A switching element driving signal is output from an output of a DC power supply circuit to an inverter circuit including a switching element, and is converted into a high-frequency AC pulse voltage. The high-frequency AC pulse voltage is converted into a voltage suitable for arc machining by a main transformer. In the power supply control method for arc processing, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor is connected between the inverter circuit and the main transformer, and a set value of an output current setting signal is set. Becomes larger, and in the high output current range, the reactor / inverter switching output current setting value when switching from control of the control winding current of the saturable reactor to control of the inverter frequency of the high frequency AC pulse voltage is determined in advance, and the output current setting signal Is smaller than the reactor / inverter switching output current set value, A switching element drive signal having a large inverter frequency is supplied to the switching element to maintain the inverter frequency at the maximum inverter frequency, and the output current setting signal and the output current detection signal are compared with each other according to the value of the comparison operation signal. The control winding current in the range from the minimum control winding current to the maximum control winding current is supplied to the saturable reactor, and the inductance value of the saturable reactor main winding is increased / decreased to increase the impedance value of the saturable reactor resonance tank. The output current is controlled by increasing or decreasing the control current. Next, when the output current setting signal becomes larger than the reactor / inverter switching output current set value, the maximum control winding current is supplied to the saturable reactor to control the control winding current. To the maximum control winding current to maximize the inductance value of the saturable reactor main winding, According to the value of the comparison operation signal, a switching element drive signal in a range from a predetermined maximum inverter frequency to a minimum inverter frequency is supplied to the switching element to increase or decrease the impedance value of the saturable reactor resonance tank. Power supply control method for arc machining that controls current. 13. An arc machining power supply control method for converting an output of a DC power supply circuit into a high frequency AC pulse voltage by an inverter circuit comprising switching, and converting the high frequency AC pulse voltage into a voltage suitable for arc machining by a main transformer. In the above, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor is connected between the inverter circuit and the main transformer, so that the set value of the output current setting signal becomes large and a high output current range is obtained. In the saturable reactor, the output of the reactor / inverter switching output current is set in advance when switching from the control of the control winding current of the saturable reactor to the control of the inverter frequency of the high-frequency AC pulse voltage. If it exceeds the value, the control winding current of the saturable reactor A reactor / inverter switching reference signal for switching to control of the inverter frequency is output, and an output current setting signal is compared with the reactor / inverter switching reference signal, and the output current setting signal is smaller than the reactor / inverter switching reference signal. Sometimes, the reactor
When the inverter switching signal becomes Low, the switching element drive signal of the maximum inverter frequency is supplied to the switching element to maintain the inverter frequency at the maximum inverter frequency, and the output current setting signal and the output current detection signal are compared and calculated. Depending on the value of the comparison operation signal, a control winding current in a range from a predetermined minimum control winding current to a maximum control winding current is supplied to the saturable reactor, and the inductance value of the saturable reactor main winding is changed. The output current is controlled by increasing or decreasing the impedance value of the saturable reactor resonance tank. Next, when the output current setting signal becomes larger than the reactor inverter switching reference signal, the reactor inverter switching signal becomes Hig.
h, the maximum control winding current is supplied to the saturable reactor, the control winding current is maintained at the maximum control winding current, the inductance value of the saturable reactor main winding is maximized, and the comparison is performed. According to the value of the operation signal, a switching element drive signal in a range from a predetermined maximum inverter frequency to a minimum inverter frequency is supplied to the switching element to increase or decrease the impedance value of the saturable reactor resonance tank, thereby increasing the output current Io. Power control method for arc processing to control the power. 14. A resonance capacitor connected between a main transformer and an inverter circuit that outputs a switching element drive signal to an inverter circuit including a switching element and converts an output of a DC power supply circuit into a high-frequency AC pulse voltage; A saturable reactor resonance tank formed by a saturable reactor is provided, a switching element drive signal is output to an inverter circuit including a switching element, and an output of a DC power supply circuit is converted into a high-frequency AC pulse voltage, and the high-frequency AC pulse is output. In a power control method for arc processing for converting a voltage into a voltage suitable for arc processing by a main transformer, a resonance capacitor and an inverter circuit for converting an output of a DC power supply circuit into a high-frequency AC pulse voltage and the main transformer. Saturable reactor resonant tan formed by saturable reactor In addition to increasing and decreasing the inductance value of the saturable reactor main winding, when the output current changes rapidly, the inverter frequency of the switching element drive signal is controlled to reduce the impedance value of the saturable reactor resonance tank. A power supply control method for arc machining in which the output current is controlled by increasing or decreasing. 15. A switching element drive signal is output to an inverter circuit including a switching element to convert an output of a DC power supply circuit into a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is suitable for arc machining by a main transformer. In the power supply control method for arc processing for converting to voltage,
A comparison operation in which a resonance capacitor connected between the inverter circuit and the main transformer and a saturable reactor resonance tank formed by a saturable reactor are connected, and an output current setting signal and an output current detection signal are compared and calculated. In response to the signal, the control winding current of the saturable reactor is output to increase or decrease the inductance value of the saturable reactor main winding, and the sequentially calculated comparison calculation signal changes abruptly to allow a predetermined fluctuation allowable. When the value exceeds the value, the inverter frequency of the switching element drive signal is controlled according to the value of the comparison operation signal, and the output current is controlled by increasing or decreasing the impedance value of the saturable reactor resonance tank, thereby controlling a power supply for arc machining. Method. 16. A switching element drive signal is output to an inverter circuit including a switching element to convert an output of a DC power supply circuit into a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is suitable for arc machining by a main transformer. In the power supply control method for arc processing for converting to voltage,
A comparison operation in which a resonance capacitor connected between the inverter circuit and the main transformer and a saturable reactor resonance tank formed by a saturable reactor are connected, and an output current setting signal and an output current detection signal are compared and calculated. According to the signal, the control winding current of the saturable reactor is increased or decreased from a predetermined minimum control winding current to a maximum control winding current to increase or decrease the inductance value of the saturable reactor main winding, and is sequentially calculated. When the comparison operation signal suddenly changes and exceeds a predetermined allowable fluctuation value, a switching element in a range from a predetermined allowable upper inverter frequency to a lower allowable lower inverter frequency according to the value of the comparison operation signal. To control the inverter frequency of the drive signal to increase or decrease the impedance value of the saturable reactor resonance tank Arc machining power supply control method for controlling an output current I. 17. The minimum control winding current is the control winding current that maximizes the inductance value of the saturable reactor main winding, and the maximum control winding current minimizes the inductance value of the saturable reactor main winding. Inverter frequency of high-frequency AC pulse voltage converted by an inverter circuit that minimizes the impedance value of the saturable reactor resonance tank when the minimum inverter frequency is the inductance value of the saturable reactor main winding and the minimum inverter frequency is the control winding current. The maximum inverter frequency is the inverter frequency of a high-frequency AC pulse voltage converted by an inverter circuit that maximizes the impedance value of the saturable reactor resonance tank when the inductance value of the saturable reactor main winding is constant. An arc heating device according to any one of claims 5 to 13. Power supply control method for construction. 18. A switching element drive signal is output to an inverter circuit including a switching element to convert an output of a DC power supply circuit into a high frequency AC pulse voltage, and the high frequency AC pulse voltage is suitable for arc machining by a main transformer. In a power supply device for arc processing that converts voltage, a constant frequency output switching element driving circuit that outputs a switching element driving signal of a predetermined fixed inverter frequency with the same pulse width to the switching element and a saturable reactor control winding are energized. A saturable reactor that controls an inductance value of a saturable reactor main winding according to a value of a control winding current to be controlled, and a saturable reactor formed by a resonance capacitor and a saturable reactor between an inverter circuit and the main transformer. Output current setting signal by setting the reactor resonance tank and output current An output current setting device that outputs an output current, an output current detector that detects an output current and outputs an output current detection signal, and outputs a comparison operation signal by comparing the output current setting signal and the output current detection signal. And a variable current output reactor control circuit for outputting a control winding current for increasing or decreasing the inductance value of the saturable reactor main winding according to the value of the comparison operation signal. 19. A switching element drive signal is output to an inverter circuit including a switching element to convert an output of a DC power supply circuit into a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is suitable for arc machining by a main transformer. In a power supply device for arc processing for converting to a voltage, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor between the inverter circuit and the main transformer, and an output current setting signal for setting an output current An output current setting device that outputs an output current, an output current detector that detects an output current and outputs an output current detection signal, and outputs a comparison operation signal by comparing the output current setting signal and the output current detection signal. A comparison operation circuit to be executed, and the setting value of the output current setting signal becomes large, and the inverter frequency of the high-frequency AC pulse voltage is increased. Inverter / reactor switching output current set value when switching from control to control of saturable reactor control winding current is predetermined, and when the output current setting signal is smaller than the inverter / reactor switching output current set value, A switching element drive signal of an inverter frequency is output to the switching element according to the value of the comparison operation signal, and when the output current setting signal is larger than the inverter / reactor switching output current setting value, the switching element of the minimum inverter frequency is output. Output drive signal,
A constant / variable frequency output switching switching element driving circuit for outputting a switching element driving signal having a minimum inverter frequency to the switching element when the output current setting signal is larger than the inverter / reactor switching output current setting value; When the signal is smaller than the inverter / reactor switching output current set value, a predetermined minimum control winding current is output to the saturable reactor control winding, and the output current setting signal is output from the inverter / reactor switching output current setting. An arc processing power supply device comprising: a constant / variable current output switching reactor control circuit that outputs a control winding current according to the value of the comparison operation signal when the value is larger than the value. 20. A switching element drive signal is output to an inverter circuit including a switching element to convert an output of a DC power supply circuit into a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is suitable for arc machining by a main transformer. In a power supply device for arc processing for converting voltage, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor connected between an inverter circuit and the main transformer, and an output current set by setting an output current. An output current setting device that outputs a setting signal; an output current detector that detects an output current and outputs an output current detection signal; and a comparison operation signal that performs a comparison operation on the output current setting signal and the output current detection signal. And a comparison operation circuit that outputs a high-frequency AC pulse voltage when the set value of the output current setting signal becomes large. An inverter / reactor switching output current set value for switching from control of the wave number to control of the control winding current of the saturable reactor is predetermined, and when the output current setting signal exceeds the inverter / reactor switching output current set value, the inverter frequency is changed. An inverter / reactor switching reference signal setting circuit for outputting an inverter / reactor switching reference signal for switching from the control of the saturable reactor to the control of the control winding current, and comparing the output current setting signal with the inverter / reactor switching reference signal. When the output current setting signal becomes the inverter / reactor switching reference signal, the inverter / reactor switching signal is set to Low.
And high switching, a minimum inverter frequency signal generating circuit for generating a signal of a minimum inverter frequency for outputting a switching element drive signal of a minimum inverter frequency, and an inverter and reactor switching signal of a low level. At the time, a switching element drive signal of an inverter frequency is output to the switching element according to the value of the comparison operation signal, and when the inverter / reactor switching signal is High,
A constant / variable frequency output switching switching element driving circuit for outputting to the switching element a switching element driving signal having an inverter frequency ranging from a predetermined maximum inverter frequency to a predetermined minimum inverter frequency according to the value of the comparison operation signal; A minimum control winding current generating circuit for outputting a minimum control winding current for maximizing the inductance value of the reactor main winding to the saturable reactor control winding, and a minimum control winding current generation circuit when the inverter / reactor switching signal is low. A control winding current is output, and when the inverter / reactor switching signal is high, control of a range from a predetermined minimum control winding current to a maximum control winding current in accordance with the value of the comparison operation signal. A constant / variable current output switching reactor control circuit that outputs winding current to a saturable reactor control winding; Arc machining power supply apparatus having. 21. A switching element drive signal is output to an inverter circuit including a switching element to convert an output of a DC power supply circuit into a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is suitable for arc machining by a main transformer. In a power supply device for arc processing that converts voltage, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor connected between an inverter circuit and a main transformer, and an output current are set by setting an output current. An output current setter for outputting a signal, an output current detector for detecting an output current and outputting an output current detection signal, and a comparison operation signal ΔI obtained by comparing the output current setting signal and the output current detection signal. And a comparison operation circuit that outputs a high-frequency AC pulse voltage when the set value of the output current setting signal becomes large. The inverter / reactor switching output current set value when switching from control of the number to control of the control winding current of the saturable reactor is predetermined, and when the output current setting signal exceeds the inverter / reactor switching output current set value, the inverter frequency is changed. An inverter / reactor switching reference signal setting circuit for outputting an inverter / reactor switching reference signal for switching from the control of the saturable reactor to the control of the control winding current, and comparing the output current setting signal with the inverter / reactor switching reference signal. When the output current setting signal becomes the inverter / reactor switching reference signal, the inverter / reactor switching signal is set to Low.
Reactor switching comparison circuit for switching from inverter to high, and NO for outputting inverter reactor switching inversion signal obtained by inverting inverter reactor switching signal
A T circuit, a minimum inverter frequency signal generating circuit for generating a signal of a minimum inverter frequency for outputting a switching element drive signal of a minimum inverter frequency, and the L-side when the inverter / reactor switching signal is low, the comparison being performed. An inverter signal switching circuit that outputs an arithmetic signal, and is at the H side when the inverter / reactor switching signal is High to generate a signal of the minimum inverter frequency; and when the inverter frequency signal switching circuit is at the L side. A constant / variable frequency output switching switching element driving circuit for outputting a switching element driving signal of an inverter frequency in a range from a predetermined maximum inverter frequency to a predetermined minimum inverter frequency to the switching element according to a value of the comparison operation signal; Inductance value of reactor main winding A minimum control winding current generating circuit that outputs a minimum control winding current for maximizing the current to the saturable reactor control winding, and the inverter / reactor switching signal that goes to the H side when the inverter / reactor switching inversion signal is High Becomes high when H is High, and outputs a minimum control winding current. When the inverter / reactor switching inversion signal is Low, it becomes L and outputs a comparison operation signal. A switching circuit for outputting a minimum control winding current to the saturable reactor control winding when the control winding current switching circuit is on the H side, and performing a comparison operation when the control winding current switching circuit is on the L side. A constant / variable current output switching reactor that outputs a control winding current ranging from a predetermined minimum control winding current to a maximum control winding current to the saturable reactor control winding according to the signal value. Arc machining power supply apparatus comprising a Le control circuit. 22. A switching element drive signal is output to an inverter circuit including a switching element to convert an output of a DC power supply circuit into a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is suitable for arc machining by a main transformer. In a power supply device for arc processing for converting to a voltage, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor between the inverter circuit and the main transformer, and an output current setting signal for setting an output current An output current setting device that outputs an output current, an output current detector that detects an output current and outputs an output current detection signal, and outputs a comparison operation signal by comparing the output current setting signal and the output current detection signal. And a control circuit for controlling the saturable reactor in a high output current range due to a large set value of the output current setting signal. A reactor-inverter switching output current setting value when switching from control of the winding current to control of the inverter frequency of the high-frequency AC pulse voltage is predetermined,
When the output current setting signal exceeds the reactor / inverter switching output current setting value, a reactor / inverter switching reference signal for outputting a reactor / inverter switching reference signal for switching from control of the control winding current of the saturable reactor to control of the inverter frequency. A setting circuit, a reactor-inverter switching comparison circuit that compares the reactor-inverter switching reference signal with an output current setting signal and outputs a reactor-inverter switching signal;
When the inverter switching signal is Low, a switching element drive signal of a predetermined maximum constant frequency is output to the switching element, and when the reactor inverter switching signal is High, according to the value of the comparison operation signal,
A constant / variable frequency output switching switching element driving circuit that outputs a switching element driving signal of an inverter frequency in a range from a predetermined maximum inverter frequency to a minimum inverter frequency to the switching element, and when the reactor inverter switching signal is Low, A control winding current corresponding to the comparison operation signal value is output to the saturable reactor control winding, and the reactor / inverter switching signal is set to H level.
and a constant / variable current output switching reactor control circuit for outputting a predetermined maximum control winding current to the saturable reactor control winding at the time of igh. 23. A switching element drive signal is output to an inverter circuit including a switching element to convert an output of a DC power supply circuit into a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is suitable for arc machining by a main transformer. In the arc machining power supply device for converting to a voltage, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor connected between the inverter circuit and the main transformer, an output current is set and output. An output current setter that outputs a current setting signal; an output current detector that detects an output current and outputs an output current detection signal; and a comparison operation that compares the output current setting signal with the output current detection signal. A comparison operation circuit for outputting a signal,
In the high output current range where the set value of the output current setting signal becomes large, the reactor / inverter switching output current set value when switching from control of the control winding current of the saturable reactor to control of the inverter frequency of the high-frequency AC pulse voltage When the output current setting signal exceeds the reactor / inverter switching output current setting value, a reactor for outputting a reactor / inverter switching reference signal for switching from control of the control winding current of the saturable reactor to control of the inverter frequency. An inverter switching reference signal setting circuit;
A reactor / inverter switching comparison circuit for comparing an output current setting signal with the reactor / inverter switching reference signal, and switching the reactor / inverter switching signal from low to high when the output current setting signal becomes the reactor / inverter switching reference signal; A maximum inverter frequency signal generating circuit for generating a signal of a maximum inverter frequency for outputting a switching element drive signal of a maximum inverter frequency, and a switching element driving circuit of the maximum inverter frequency when the reactor / inverter switching signal is low. A signal is output to the switching element, and when the reactor-inverter switching signal is high, the inverter frequency in a range from a predetermined maximum inverter frequency to a minimum inverter frequency is determined according to the value of the comparison operation signal. A constant / variable frequency output switching switching element driving circuit that outputs a switching element driving signal to the switching element, and a maximum control current for minimizing the inductance value of the saturable reactor main winding is output to the saturable reactor control winding. A maximum control winding current generating circuit and a control winding in a range from a predetermined minimum control winding current to a maximum control winding current according to the comparison operation signal value when the reactor / inverter switching signal is Low. A constant / variable current output switching reactor control circuit that outputs a line current to a saturable reactor control winding and outputs a maximum control winding current when the reactor / inverter switching signal is high. Power supply. 24. A switching element drive signal is output to an inverter circuit including a switching element to convert an output of a DC power supply circuit into a high-frequency AC pulse voltage, and the high-frequency AC pulse voltage is suitable for arc machining by a main transformer. In the arc machining power supply device for converting to a voltage, a saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor connected between the inverter circuit and the main transformer, an output current is set and output. An output current setter that outputs a current setting signal; an output current detector that detects an output current and outputs an output current detection signal; and a comparison operation that compares the output current setting signal with the output current detection signal. A comparison operation circuit for outputting a signal,
A reactor-inverter switching output current setting value when switching from control of the control winding current of the saturable reactor to control of the inverter frequency of the high-frequency AC pulse voltage when the set value of the output current setting signal becomes large, When the current setting signal exceeds the reactor / inverter switching output current setting value, a reactor / inverter switching reference signal setting for outputting a reactor / inverter switching reference signal for switching from control of the control winding current of the saturable reactor to control of the inverter frequency. Circuit, and an output current setting signal is compared with the reactor / inverter switching reference signal. When the output current setting signal becomes the reactor / inverter switching reference signal, the reactor / inverter switching for switching the reactor / inverter switching signal from low to high A comparison circuit; A NOT circuit for outputting inverted reactor inverter switching inverted signal Akutoru inverter switching signal, and the maximum inverter frequency signal generating circuit for generating a signal of a maximum inverter frequency for outputting a switching element driving signal of the maximum inverter frequency,
When the reactor / inverter switching inversion signal is High, the signal goes to the H side to output a signal of the maximum inverter frequency, and when the reactor / inverter switching inversion signal is Low, it goes to the L side to output the comparison operation signal. An inverter frequency signal switching circuit, when the inverter frequency signal switching circuit is on the H side, outputs a switching element drive signal of the maximum inverter frequency to a switching element; and when the inverter frequency signal switching circuit is on the L side, A constant / variable frequency output switching switching element driving circuit for outputting a switching element driving signal having an inverter frequency ranging from a predetermined maximum inverter frequency to a predetermined minimum inverter frequency to the switching element in accordance with a value of the comparison operation signal; and a saturable reactor. Minimum inductance value of main winding And a maximum control winding current generating circuit for outputting a maximum control current to the saturable reactor control winding to output the comparison operation signal to the L side when the reactor / inverter switching signal is low, and A control winding current switching circuit that goes high when the inverter switching signal is high and outputs a maximum control current; and a comparison operation signal that is input and predetermined when the control winding current switching circuit is low. The control winding current in the range from the minimum control winding current to the maximum control winding current is output to the saturable reactor control winding.
And a constant / variable current output switching reactor control circuit that receives the maximum control winding current when the side is on the side and minimizes the inductance value of the saturable reactor main winding. 25. A saturable reactor resonance tank formed by a saturable reactor and a resonant capacitor connected between an inverter circuit for converting an output of the DC power supply circuit into a high-frequency AC pulse voltage and a main transformer. While maximizing the inductance value of the saturated reactor, when the output current changes rapidly, the output current is controlled by controlling the inverter frequency of the switching element drive signal to increase or decrease the impedance value of the saturable reactor resonance tank. An arc processing power supply device for controlling, comprising: outputting a switching element drive signal to an inverter circuit including a switching element; converting an output of a DC power supply circuit into a high-frequency AC pulse voltage; and converting the high-frequency AC pulse voltage into a main transformer. For arc machining, which converts the voltage into a voltage suitable for arc machining. A saturable reactor resonance tank formed by a resonance capacitor and a saturable reactor connected between the inverter circuit and the main transformer, an output current setting for setting an output current and outputting an output current setting signal. Device, an output current detector that detects an output current and outputs an output current detection signal, a comparison operation circuit that compares the output current setting signal and the output current detection signal and outputs a comparison operation signal, A variable current output reactor control circuit that outputs a control winding current of the saturable reactor according to the value of the comparison operation signal to increase or decrease the inductance value of the saturable reactor main winding, and the comparison operation signal that is sequentially calculated is A load fluctuation detection arithmetic circuit for outputting a load fluctuation detection signal when the load fluctuation suddenly exceeds a predetermined fluctuation allowable value; And a load dynamic switching switching element drive circuit that controls the inverter frequency of the switching element drive signal in accordance with the value of the comparison operation signal to increase or decrease the inductance value of the saturable reactor main winding. And an arc processing power supply device for controlling the output current by controlling the inverter frequency of the switching element drive signal when the output current changes rapidly to increase or decrease the impedance value of the saturable reactor resonance tank.