JP2002176778A - Power supply device and air conditioner using the power supply device - Google Patents

Abstract

(57) [Problem] To provide a power supply device which improves a power factor by increasing a conduction angle of an input current by simple control and reduces a harmonic component of the input current, and an air conditioner using the same. A power supply device includes a rectifier circuit for rectifying a voltage of an AC power supply, and a reactor connected to the rectifier circuit.
And, including a plurality of switching elements and a capacitor circuit,
A power factor improving circuit 7 for inputting an output voltage of the rectifying circuit 2, and a changeover switch portion connected between the rectifying circuit 2 and the power factor improving circuit 7 for switching a current path formed therebetween between conduction and cutoff. 12, a changeover switch driving unit 40 for controlling the energization state of the changeover switch unit 12, and a power factor improving circuit 7
A pulse signal control unit 22 for generating and outputting a pulse signal for turning on and off each switching element, and a switch driving unit 23 for receiving the pulse signal from the pulse signal control unit 22 and driving the switching element of the power factor correction circuit 7. Is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for converting an alternating current into a direct current, reducing a harmonic component of an input current, improving a power factor and supplying a desired power supply voltage, and an air conditioner using the same. About.

[0002]

2. Description of the Related Art Conventionally, as an AC-DC conversion circuit, a capacitor input type rectifier circuit for inputting an AC voltage to a diode rectifier circuit to obtain a pulsating output and smoothing the pulsating output with a capacitor to obtain a DC voltage has been known. Used in various fields. In the capacitor input type rectifier circuit, the input current has a narrow current conduction angle, a low power factor, and there is a lot of reactive power, so it is not possible to use power effectively, and it contains many harmonic components and is connected to the same power supply system Problems with equipment are a problem. To solve this problem, Japanese Patent Application Laid-Open No. 9-182 discloses a technique for improving a power factor and reducing harmonic components.
There is a power supply device disclosed in Japanese Patent No. 457.

This power supply device has a circuit configuration as shown in FIG. 26 (a). As shown in FIG. 26 (b), an AC voltage Vin inputted from an AC power supply 101 is converted into a pulsating output voltage by a rectifier circuit 103. It has a reactor 102 for conversion. As a result, the rush of the input current Iin can be reduced, and as a result, the current conduction angle increases, so that the power factor can be improved and the harmonic components included in the input current Iin can be reduced.

For example, when the power supply device is used in an air conditioner, the load 105 serves as a compressor motor and an inverter for driving the motor. When the AC power supply 101 is at 100 V, the relay circuit 130 is normally turned on to operate as a voltage doubler rectifier circuit. Particularly, in a low load region, the power supply becomes a full-wave rectifier circuit by shutting off the relay circuit 130 so that the output DC voltage can be suppressed low. At this time, the loss in the inverter and the motor is reduced. Can be reduced.

As described above, in the conventional power supply device shown in FIG. 26, the power factor can be improved by inserting only passive components having a simple structure, and the energizing state of the relay circuit 130 is switched to change the load 105. Loss can be reduced.

Another technique is disclosed in JP-A-11-206.
A power supply device disclosed in Japanese Patent Publication No. 130 is being studied. This power supply device has a circuit configuration shown in FIG. Hereinafter, a detailed operation of the power supply device will be described.

In FIG. 27A, the control section 132 outputs a pulse signal for turning on the switching element 131 for a predetermined time in synchronization with the zero-cross point of the AC power supply 101.
As a result, a current for short-circuiting the AC power supply 101 flows through the rectifier circuit 133 and the switching element 131 via the reactor 102, and thus the input current is
Flows from the zero crossing point of And switching element 1
When the switch 31 is turned off, the current flows through the reactor 102, the rectifier circuit 103, the capacitors 120a and 120b, or the smoothing capacitor 104. As a result, the current conduction angle can be greatly increased, and the power factor can be greatly improved.

When this power supply is also used for an air conditioner, the load 105 is a compressor motor and an inverter for driving the motor. Therefore, similarly, by setting the relay circuit 130 to the cut-off state in the low load region, the relay circuit 130 becomes a full-wave rectifier circuit, and loss in the inverter and the motor can be suppressed.

As described above, the conventional power supply device shown in FIG. 27 can greatly improve the power factor by a simple configuration and control, and suppresses the loss of the load 105 by switching the energized state of the relay circuit 130. be able to.

[0010]

However, in the conventional power supply shown in FIG. 26, the power factor can be improved with a simple configuration, but the improvement effect is small, and a sufficient power factor cannot be obtained. . Also, in order to obtain a high power factor with this circuit configuration, it is necessary to increase the value of the reactor, which leads to an increase in the size of the components and an increase in the loss associated therewith. Further, there is a problem that when the energization state of the relay circuit 130 is switched, the output voltage may fluctuate greatly and cause a problem to the load 105.

In the power supply device shown in FIG. 27, the power factor can be greatly improved by simple switching control. However, when the power supply device is used for an air conditioner or the like, 1) When the input is 200 V, the reactor is large. 2) The circuit size cannot be shared due to the difference in the size of the reactor between the input of 100 V and the input of 200 V, and 3) When the energized state of the relay circuit 130 is switched. However, there is a problem that the output voltage may fluctuate greatly and cause a problem to the load 105.

The present invention solves such a conventional problem, and can obtain a high power factor with a simple configuration and control. The filter circuit is caused by an increase in loss and an increase in noise in a switching element. It is an object of the present invention to provide a power supply device capable of preventing an increase in loss in the power supply and suppressing harmonics with low loss.

A power supply device capable of preventing the increase in the size of the reactor and the resulting loss even at the time of input of 200 V, and having the same circuit configuration at the time of input of 100 V and 200 V to share the circuit. The purpose is to provide.

It is still another object of the present invention to provide a power supply device capable of suppressing a large change in output voltage generated when a relay circuit is switched.

It is another object of the present invention to provide an air conditioner using such a power supply device.

[0016]

In order to solve the above problems, a first power supply device according to the present invention comprises: (a) a rectifier circuit for rectifying an output voltage of an AC power supply and converting the output voltage to a DC voltage;
(B) a reactor connected to the rectifier circuit, and (c)
Power factor improvement circuit for inputting the output voltage of the rectifier circuit (The power factor improvement circuit includes a plurality of switching elements connected in series, and changes the current path of the input current flowing from the AC power supply by turning on and off. It comprises a switching circuit, a capacitor circuit composed of a plurality of capacitors connected in series, and a backflow prevention rectifying element for preventing electric charges charged in the capacitor from flowing back to the switching circuit when the switching circuit is on. The switching circuit and the capacitor circuit are arranged in parallel.
A connection point between the switching elements and a connection point between the capacitors are connected. An end point of the switching circuit and an end point of the capacitor circuit are connected via a backflow prevention rectifier. ) And (d) connected between one of the input terminals of the rectifier circuit and a connection point between the switching elements of the power factor correction circuit,
Changeover switch means for switching the energization state of the current path formed between the conduction state and the interruption state, (e) switch control means for controlling the energization state of the changeover switch means, and (f) each switching of the power factor improvement circuit Turn on the element
A pulse signal control unit that generates and outputs a pulse signal to be turned off; and (g) a switch drive unit that receives a pulse signal from the pulse signal control unit and drives a switching circuit of the power factor correction circuit.

A second power supply device according to the present invention is a power supply device having the circuit configuration of the first power supply device, wherein the pulse signal control means controls the power factor improvement circuit in a half cycle of the AC power supply voltage. A pulse signal for turning on at least one of the plurality of switching elements for a predetermined time is output, and a switching signal for switching an energized state of the switch means is output to the switch control means.

A third power supply device according to the present invention, in the second power supply device, includes a zero cross detection means for detecting a zero cross point of the power supply voltage and outputting a zero cross detection signal. At this time, the pulse signal control means outputs a pulse signal for turning on the switching element of the power factor correction circuit for a predetermined time based on the zero cross detection signal from the zero cross detection means.

The fourth power supply according to the present invention is the second or third power supply, further comprising a voltage polarity determining means for determining the polarity of the power supply voltage. At this time, the pulse signal control unit refers to the determination result of the voltage polarity determination unit at least when the changeover switch unit is in the conductive state, and switches the switching element of the power factor improvement circuit according to the polarity in each half cycle of the power supply voltage. A pulse signal for turning on for a predetermined time is output.

A fifth power supply according to the present invention, in any one of the second to fourth power supplies, further comprises an input current detecting means for detecting a current value of the AC power supply. At this time, the pulse signal control means switches the energization state of the switch means when the pulse signal is off and the current value obtained from the input current detection means is zero.

A sixth power supply device according to the present invention, in the second or fourth power supply device, detects a zero-cross point of the power supply voltage and outputs a zero-cross detection signal, and receives the zero-cross detection signal. Timer means for outputting a switching timing signal after a predetermined time has elapsed. At this time, the pulse signal control means receives the switching timing signal from the timer means and switches the energized state of the switch means.

A seventh power supply device according to the present invention is the power supply device according to any one of the second and sixth power supply devices, wherein the pulse signal control means switches the changeover switch means to the cutoff state before and after switching the energization state of the changeover switch means. Generates a first pulse signal for turning on a plurality of switching elements of the power factor correction circuit for different predetermined times, and switches and outputs the output pattern of the first pulse signal every half cycle of the AC power supply voltage. A second pulse signal for turning on one of the switching elements of the power factor correction circuit for a predetermined time when the changeover switch means is in a conductive state, and generating a second pulse signal every half cycle of the AC power supply voltage; The signal output pattern is switched and output.

According to an eighth power supply device of the present invention, in the seventh power supply device, the pulse signal control means turns on the shortest pulse signal among the first pulse signals output when the changeover switch means is in the cutoff state. The time is made equal to the on-time of the second pulse signal that is output when it is in the conductive state.

A ninth power supply according to the present invention, in any one of the second to eighth power supplies, further comprises a load state detecting means for detecting a magnitude of a load. At this time,
The switch control means switches the conduction or cutoff state of the changeover switch means according to the magnitude of the load obtained from the load state detection means.

A tenth power supply device according to the present invention is the ninth power supply device, wherein the load converts the direct current to the alternating current so that the load supplies a driving voltage to the motor device and the motor device.
The load state detecting means is an inverter.
The amount of change occurring due to a change in the state of the motor device or the motor device is detected.

An eleventh power supply according to the present invention, in any one of the first and tenth power supplies, includes a smoothing capacitor for smoothing an output voltage of the power factor correction circuit.

The air conditioner according to the present invention uses any one of the above power supply devices as a power supply device.

[0028]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a power supply device according to the present invention. Note that the same reference numerals in all drawings indicate the same or equivalent components or portions.

(Embodiment 1) FIG. 1 is a circuit diagram showing an embodiment of a power supply device according to the present invention. In FIG. 1, the power supply includes an AC power supply 1, a rectifier circuit 2, and a reactor 3.
And a power factor improving circuit 7, a smoothing capacitor 8, and a changeover switch section 12.

The power factor improving circuit 7 includes two switching elements 4a and 4b, two capacitors 5a and 5b, and two rectifying elements 6a and 6b for preventing backflow. The midpoint of the series connection of the two switching elements 4a and 4b and the midpoint of the series connection of the two capacitors 5a and 5b are connected to each other. The switching element 4a and the capacitor 5a are connected via a backflow prevention rectifying element 6a.
b and the capacitor 5b are connected via the backflow prevention rectifier 6b.

The changeover switch section 12 is connected between the connection point of the rectification elements 2b and 2d of the rectification circuit 2 and the connection point of the switching elements 4a and 4b of the power factor correction circuit 7. The changeover switch unit 12 is turned on / off to switch the conduction state of the current path between the connection points to conduction or cutoff. The changeover switch section 12 is composed of a relay circuit as a mechanical switch, a semiconductor element as an electric switch, and the like. In the present embodiment, the changeover switch section 12 is constituted by a relay circuit. The changeover switch unit 12 may be connected between a connection point of the rectification elements 2a and 2c of the rectification circuit 2 and a connection point of the switching elements 4a and 4b of the power factor correction circuit 7.

The rectifier circuit 2 includes a plurality of rectifier elements 2a, 2b,
2c and 2d, which rectify the AC voltage and output a pulsating voltage. Reactor 3 performs power factor improvement. The smoothing capacitor 8 smoothes the output voltage of the power factor correction circuit 7. A load 9 is connected to the power supply device.

A self-extinguishing semiconductor such as a power transistor, a power MOSFET or an IGBT is used for the switching means 4a and 4b. Further, specific examples of the load include a heating wire, an inverter, and lighting equipment and a motor connected to the inverter and operating.

Further, the power supply device includes a zero-cross detection unit 21, a pulse signal control unit 22, a switch driving unit 23, and a changeover switch driving unit 40 as means for controlling the power factor improvement circuit 7.

The zero-cross detector 21 detects a zero-cross point of the AC power supply 1 and outputs a zero-cross detection signal. The pulse signal control unit 22 receives the zero-cross detection signal from the zero-cross detection unit 21 and generates and outputs a pulse signal for driving the switching units 4a and 4b. The pulse signal control unit 22 is configured by a general-purpose logic circuit or a microcomputer. The switch drive section 23 receives the pulse signal from the pulse signal control section 22 and drives the switching elements 4a, 4b. Further, the changeover switch drive section 40 switches the energization state of the changeover switch section 12 on and off. In the present embodiment, the changeover switch driving section 40 receives the changeover signal from the pulse signal control section 22 and switches the energization state of the changeover switch section 12 on and off.

FIG. 2 is a diagram showing the waveforms of the power supply voltage, the input current, and the pulse signal in the above power supply device when the switch 12 is turned off. FIG. 3 is a diagram illustrating the waveforms of the power supply voltage, the input current, and the pulse signal when the energization state of the changeover switch unit 12 is on. FIGS. 4 and 5 are views showing the manner in which the current path changes when the changeover switch unit 12 is turned off and turned on, respectively. Hereinafter, the power supply device of the present embodiment will be described in detail with reference to FIGS.

In all the embodiments described below, the symbol "Vin" in the main waveform diagram is the voltage waveform of the AC power supply 1, and "Iin" is the input current waveform, and the direction of each arrow is the positive direction. . “Pa” is a pulse signal for driving the switching element 4a, and “Pb” is a pulse signal for driving the switching element 4b. "Va",
"Vb" is the voltage across the capacitors 5a and 5b,
“Vdc” indicates a voltage across the smoothing capacitor 8.

The pulse signal control unit 22 generates a pulse signal for turning on at least one of the switching elements 4a and 4b for a predetermined time in synchronization with the zero cross point of the voltage Vin of the AC power supply 1 detected by the zero cross detection unit 21. Output. In the example of FIG. 2, the switching element 4a is turned on in the positive half cycle of the AC power supply 1, and the switching element 4b is turned on for a predetermined time in the negative half cycle. At this time, the changeover switch driving section 40 has the changeover switch section 12 in the off state.

In FIG. 2, when the switching element 4a is on, the voltage on the load 9 side as viewed from the AC power supply 1 becomes equal to the voltage Vb across the capacitor 5b. The input current Iin starts flowing in the path a) and increases until the pulse signal is turned off.

When the pulse signal is turned off, the voltage on the load 9 side as viewed from the AC power supply 1 becomes equal to the voltage Vdc across the smoothing capacitor 8. At this time, if Vin is smaller than Vdc, the input current Iin temporarily decreases. From the point where the voltage value Vin exceeds the voltage Vdc across the smoothing capacitor 8, a current for charging the capacitor 8 flows again along the path shown in FIG.

As a result, the rise of the input current can be accelerated, and the current conduction period can be extended. Similarly, in the negative half cycle, when the switching element 4b is in the on state, the voltage Vin is equal to the voltage V across the capacitor 5a.
Since the input current Iin flows through the path shown in FIG. 4B from the point exceeding a, the current conduction period can be extended.

By repeating these operations every half cycle of the AC power supply 1, the current conduction period can be extended and a sufficiently high power factor can be obtained.

When the changeover switch section 12 is in the OFF state, the power supply apparatus performs a power factor improving operation based on the full-wave rectifier circuit. For example, if the voltage value of the AC power supply 1 is 200 V AC, the power supply is applied to the load 9. The output voltage becomes the voltage Vdc across the smoothing capacitor 8 and has a value of about 280V. Here, the voltage applied to reactor 3 when switching elements 4a and 4b are turned on is power supply voltage Vi.
Since n is relaxed by the voltage Va, Vb across the capacitors 5a, 5b, the size of the reactor 3 can be suppressed.

Next, a power supply device for performing the control shown in FIG. 3 will be described. In the example of FIG. 3 as well, the switching element 4a is turned on for a predetermined time in the positive half cycle of the AC power supply 1, and the switching element 4b is turned on for a predetermined time in the negative half cycle. At this time, the changeover switch driving section 40 has the changeover switch section 12 in the ON state.

In FIG. 3, when the switching element 4a is in the ON state, a current Iin for short-circuiting the AC power supply 1 via the reactor 3 from the zero cross point of the voltage value Vin of the AC power supply 1 flows through the path of FIG. . When the pulse signal is turned off, a current for charging the capacitor 5a flows through the path shown in FIG. 5B.

As a result, the input current rises from the zero-cross point of the AC power supply 1, so that the current conduction period can be extended. Similarly, in the negative half cycle, the switching element 4b is turned on and off so that the short-circuit current of the AC power supply 1 shown in FIG. 5C and the charging current to the capacitor 5b shown in FIG. The conduction period can be extended.

By repeating these operations every half cycle of the AC power supply 1, the current conduction period can be extended, so that a sufficiently high power factor can be obtained.

When the changeover switch unit 12 is in the ON state, the power supply device performs a power factor improvement operation based on the voltage doubler rectifier circuit. For example, if the voltage value of the AC power supply 1 is 100 V AC, it is applied to the load 9. The output voltage becomes the voltage Vdc across the smoothing capacitor 8 and has a value of about 280V. Therefore, by turning on and off the changeover switch section 12, the same voltage can be applied to the load 9 regardless of whether the voltage value of the AC power supply 1 is 100 V or 200 V.

Further, the reactor 3 can be downsized even when the power supply voltage Vin is 200 V, so that the same specifications as those when the power supply voltage Vin is 100 V can be used, and the components of the power supply device can be made the same.

As described above, according to the power supply device of the present embodiment, a sufficiently high power factor can be obtained by a simple configuration and control, so that harmonic components contained in the input current can be sufficiently suppressed. Switching elements 4a, 4b
Since the number of times of switching is small, the generated noise is small and the loss in the filter circuit and the switching elements 4a and 4b can be suppressed low. Further, since the power factor is surely improved by detecting the zero cross point, the reliability of the device can be increased.

Furthermore, even if the power supply voltage is 100 V,
However, since the power factor can be improved using the same circuit configuration and components, it is possible to provide a power supply device that can handle a plurality of power supply systems and can reduce the number of development steps.

(Embodiment 2) FIGS. 6, 7 and 8 are circuit diagrams showing another embodiment of the power supply device according to the present invention. The power supply device shown in FIGS. 6, 7, and 8 further includes a voltage polarity determination unit 41 that determines the polarity of the voltage Vin of the AC power supply 1 in addition to the circuit configuration shown in FIG.

The voltage polarity discriminating section 41 discriminates the voltage polarity of the other end with respect to the connection point with the changeover switch section 12 at the AC input terminal of the rectifier circuit 2. Further, the changeover switch drive section 40 receives the changeover signal from the pulse signal control section 22 and switches the energization state of the changeover switch section 12 between ON and OFF. Hereinafter, the power supply device shown in FIGS. 6, 7, and 8 will be described in detail.

FIG. 9 shows an AC power supply 1 in the power supply device of FIG.
Voltage waveform Vin, input current waveform Iin, pulse signal P
a and Pb, voltages Va and V across capacitors 5a and 5b
3B is a diagram showing a voltage Vdc across the smoothing capacitor 8.

In FIG. 6, the changeover switch section 12 is in the off state. At this time, the pulse signal control unit 22 outputs pulse signals Pa and Pb as shown in FIG. That is, the pulse signal control unit 22 outputs a pulse signal Pa for turning on the switching element 4a for a predetermined time in the positive half cycle in synchronization with the zero crossing point of the AC power supply 1, and switches the switching element 4b in the negative half cycle. A pulse signal Pb for turning on for a predetermined time is output.

Thus, in the positive half cycle of the AC power supply 1, the current is supplied by the charging current to the capacitor 5b shown in FIG. 4A, and in the negative half cycle by the charging current to the capacitor 5a shown in FIG. 4B. The conduction period can be extended, and a sufficient power factor can be obtained.

When the changeover switch section 12 is in the OFF state as shown in FIG. 6, the pulse signal control section 22 switches the switching element 4b in the positive half cycle of the AC power supply 1 and the negative state, as shown in FIG. When the pulse signals Pa and Pb for turning on the switching element 4a for a predetermined time in the half cycle of are output, although the current path is different from the case of the control in FIG. Power factor can be obtained.

Next, the case where the changeover switch section 12 of the power supply device is in the ON state will be described. 7 and 8, the connection point of the rectification circuit 2 to which the changeover switch unit 12 is connected is the connection point A, and the other connection point is the connection point B of the connection points connected to the two AC input terminals of the rectification circuit 2. I do.

FIGS. 10 and 11 show voltage waveforms Vi of the AC power supply 1 in the power supply devices of FIGS. 7 and 8, respectively.
3 is a diagram showing n, input current waveform Iin, pulse signals Pa and Pb, voltage Vb across capacitor 5b, and voltage Vdc across smoothing capacitor 8. FIG. In the power supply device of FIG. 7, a connection point A between the changeover switch section 12 and the rectification circuit 2 is a connection point between the rectification elements 2b and 2d.

When the voltage Vin of the AC power supply 1 is positive,
The potential at the connection point B with respect to the connection point A has a positive value.
When the pulse signal control unit 22 detects that the changeover switch unit 12 is in the ON state and the voltage polarity determination unit 41 detects that the potential of the connection point B with respect to the connection point A of the changeover switch unit 12 is positive, as shown in FIG. A pulse signal Pa for turning on the switching element 4a of the power factor correction circuit 7 for a predetermined time.
Is output. At this time, when the pulse signal Pa is on, the current Iin for short-circuiting the AC power supply 1 shown in FIG.
Flows and the charging current of the capacitor 5a shown in FIG. 5B flows in the off state, so that the current conduction period can be extended.

When the AC power supply 1 is negative, the potential of the connection point B with respect to the connection point A has a negative value. When the pulse signal control unit 22 detects that the changeover switch unit 12 is in the ON state and the voltage polarity determination unit 41 detects that the potential of the connection point B with respect to the connection point A of the changeover switch unit 12 is negative, the pulse signal control unit 22 shown in FIG.
As shown in (1), a pulse signal Pb for turning on the switching element 4b of the power factor correction circuit 7 for a predetermined time is output. At this time, when the pulse signal Pb is in the ON state, FIG.
Since the current Iin for short-circuiting the AC power supply 1 shown in FIG. 5 flows and the charging current for the capacitor 5b shown in FIG. 5D flows in the off state, the current conduction period can be extended. With the above operation, a sufficient power factor can be obtained.

Next, the power supply device shown in FIG. 8 will be described. In the power supply device of FIG. 8, a connection point A between the changeover switch section 12 and the rectifier circuit 2 is a connection point between the rectifier elements 2a and 2c.

When the voltage Vin of the AC power supply 1 is positive,
The potential of the connection point B with respect to the connection point A has a negative value. When the pulse signal control unit 22 detects that the changeover switch unit 12 is in the ON state and the voltage polarity determination unit 41 detects that the potential of the connection point B with respect to the connection point A of the changeover switch unit 12 is negative, as shown in FIG. A pulse signal Pa for turning on the switching element 4b of the power factor correction circuit 7 for a predetermined time is output. At this time, when the pulse signal Pa is on, a current Iin for short-circuiting the AC power supply 1 shown in FIG. 12A flows, and when the pulse signal Pa is off, a charging current for the capacitor 5b shown in FIG. 12B flows. In addition, the current conduction period can be extended.

When the AC power supply 1 is negative, the potential of the connection point B with respect to the connection point A has a positive value. When the pulse signal control unit 22 detects that the changeover switch unit 12 is in the ON state and the voltage polarity determination unit 41 detects that the potential of the connection point B with respect to the connection point A of the changeover switch unit 12 is positive, the pulse signal control unit 22 shown in FIG.
As shown in (1), a pulse signal Pb for turning on the switching element 4a of the power factor correction circuit 7 for a predetermined time is output. At this time, when the pulse signal Pb is on,
A current Iin for short-circuiting the AC power supply 1 shown in FIG.
In the off state, the charging current of the capacitor 5a shown in FIG. 12D flows, so that the current conduction period can be extended. With the above operation, a sufficient power factor can be obtained.

When the changeover switch section 12 is turned on, the power factor improving operation cannot be performed unless the corresponding switching elements 4a and 4b are driven by the circuit configuration according to the voltage polarity of the AC power supply 1. In the present embodiment, the potential of the other point is detected with reference to the connection point of the changeover switch unit 12 of the rectifier circuit 2, and if this is a positive potential, the switching element 4a is driven.
If the potential is negative, the switching element 4b is driven. Thereby, the power factor can be surely improved regardless of the connection position of the changeover switch section 12.

As described above, according to the power supply device of the present embodiment, it is possible to provide a power supply device which is simple in configuration and control, can obtain a sufficient harmonic suppression effect, and has a low loss. In addition to the feature of 1, the power factor can be surely improved irrespective of the connection position between the changeover switch section 12 and the rectifier circuit 2. Therefore, the changeover switch unit 12
Is fixed to one side, and the changeover switch 12
It is possible to prevent trouble such as trouble of setting a pulse signal after confirming the connection point and malfunction due to a setting error. This makes it possible to provide a highly reliable power supply device with a small number of installation steps.

The method of determining the switching element to be driven according to the voltage polarity of the AC power supply 1 is not limited to the method of this embodiment. In addition, the function performed by the voltage polarity determination unit 41 can be included in the zero-cross detection unit 21.

(Embodiment 3) FIG. 13 is a circuit configuration diagram of still another embodiment of the power supply device according to the present invention. FIG.
3 includes an input current detection unit 42 in addition to the circuit configuration shown in FIG.

The input current detector 42 is provided in front of the rectifier circuit 2, detects the value of the AC current Iin, and outputs it to the pulse signal controller 22.

The pulse signal control section 22 is provided with the changeover switch section 1
In order to minimize the effect on the input current waveform when switching the energization state of the second input current, the input current Iin before and after the switching is switched.
The pulse signal is controlled so that the conduction state of the changeover switch unit 12 is switched at a timing at which the current path, that is, the current waveform, that is, the influence on the power factor improvement operation can be eliminated without changing the conduction path.

By selecting the current non-conducting period after the end of the input current conducting in each half cycle of the AC power supply 1 as the switching timing of the changeover switch section 12,
Impact is minimized. The pulse signal control unit 22
When the pulse signals output to the switching elements 4a and 4b are in the off state and the current value detected from the input current detection unit 42 is zero, the current non-conduction period is detected.

FIGS. 14 and 15 show the voltage waveform Vin and the input current waveform Ii of the AC power supply 1 in the power supply device of FIG.
3 is a diagram showing n, pulse signals Pa and Pb, an ON state “SW ON” and an OFF state “SW OFF” of the changeover switch unit 12. FIG.

Hereinafter, the power supply device shown in FIG. 13 will be described in detail. First, a case where the changeover switch unit 12 is switched from the off state to the on state in the power supply device of FIG. 13 will be described.

When the changeover switch section 12 is in the OFF state, the pulse signal control section 22 operates as shown in FIG.
The switching element 4a is turned on in the positive half cycle and the switching element 4b is turned on for a predetermined time in the negative half cycle to perform the power factor improvement operation. At this time, the power supply device performs a power factor improving operation based on the full-wave rectifier circuit.

When switching the changeover switch unit 12 to the ON state, the pulse signal control unit 22 detects a current non-conducting period after the end of current conduction in a half cycle of the AC power supply 1 as a switching timing. The method of detecting the current non-conduction period is as described above. In the current non-conduction period, the pulse signal control section 22 outputs a signal for switching the changeover switch section 12 to the ON state to the changeover switch drive section 40. The changeover switch drive section 40 receives the changeover signal and sets the changeover switch section 12 to the ON state.

After switching the changeover switch unit 12 to the ON state, the pulse signal control unit 22 operates the switching element 4a in the positive half cycle of the AC power supply 1 and the switching element 4b in the negative half cycle as before the switching. Is output as a pulse signal for turning on for a predetermined time. As a result, the power supply device performs a power factor improving operation based on the voltage doubler rectifier circuit. By the switching operation of the changeover switch section 12, the influence of the input current on the waveform distortion can be suppressed.

Next, FIG. 15 shows a case where the changeover switch section 12 is switched from the ON state to the OFF state. Also in this case, similarly to the above, the pulse signal control unit 22 detects the current non-conduction period after the end of the input current conduction in the half cycle of the AC power supply 1, and switches the changeover switch unit 12 from the on state during the current non-conduction period. Switch to off state. Thereby, the influence of the input current on the waveform distortion can be suppressed.

As described above, according to the power supply device of the present embodiment, it is possible to provide a power supply device which is simple in configuration and control, can obtain a sufficient harmonic suppression effect, and has a low loss. In addition to the features of the first aspect, it is possible to suppress sharp waveform distortion of the input current that occurs when the energization state of the changeover switch unit 12 is switched, and to reduce the specification specifications of each component of the power supply device. Therefore, the size of the device can be reduced, and a highly reliable power supply device can be realized.

(Embodiment 4) FIG. 16 is a circuit diagram showing still another embodiment of the power supply device according to the present invention.
16, the power supply device includes a timer unit 43 instead of the input current detection unit 42 in the circuit configuration shown in FIG.

The timer 43 receives a zero-cross detection signal output from the zero-cross detector 21 every half cycle of the AC power supply 1, and outputs a switching signal indicating a timing for switching the switch 12 after a predetermined time has elapsed.

That is, also in this embodiment, when switching the energization state of the changeover switch section 12 in the same manner as in the third embodiment, in order to suppress the influence of input current on waveform distortion, current non-conduction after termination of current conduction is performed. Detect the period.

In the present embodiment, the timer 43 is used as a method of detecting the current non-conduction period, and the current is detected by appropriately setting the elapsed time from the zero-cross detection point. The easiest way to set the elapsed time is to measure and set in advance the time from the zero-cross point to the end of current conduction according to the state of the load 9. The pulse signal control unit 22 receives the switching signal from the timer unit 43 and switches the energization state of the switching unit 12. The detailed switching operation is the same as in the third embodiment.

As described above, according to the power supply device of the present embodiment, similar to the third embodiment, the structure and control of the device can be simplified, a sufficient harmonic suppression effect can be obtained, and a low-loss power supply device can be obtained. In addition to the feature that it can be provided, it is possible to suppress sharp waveform distortion of the input current that occurs when the energization state of the changeover switch unit 12 is switched, and to reduce the specification specifications of each component of the power supply device. can do. That is, a small and highly reliable power supply device can be provided.

Further, when an arithmetic unit such as a microcomputer is used as the pulse signal control unit 22, the timer unit 43 can also be incorporated in the microcomputer, and a new configuration such as the input current detection unit 42 in the third embodiment is used. Since the present invention can be realized without adding an element, it is possible to provide a highly reliable power supply device that can be further reduced in size.

(Embodiment 5) Still another embodiment of the power supply device of the present invention will be described with reference to FIG. 1, FIG. 4, FIG. 17, and FIG.

FIG. 17 is a diagram showing the voltage waveform Vin of the AC power supply 1, the input current waveform Iin, the pulse signals Pa and Pb, the voltage Vb across the capacitor 5b, and the voltage Vdc across the smoothing capacitor 8 in the power supply device of FIG. is there. FIG.
, The changeover switch unit 12 is in the OFF state, the pulse signal control unit 22 outputs the long pulse signal Pa and the short pulse signal Pb in the positive half cycle of the AC power supply 1, and outputs the short pulse signal Pa and the long pulse in the negative half cycle. The pulse signal Pb is output.

In this case, a short-circuit current of the AC power supply 1 via the reactor 3 as shown in FIG. 4D and a charging current of the capacitors 5a and 5b shown in FIG. 4A or 4B flow. The current conduction period can be extended, and the power factor can be improved.

At this time, the reactor 3 caused by the short-circuit current
Capacitor 5 due to energy storage and charging current
Since energy is simultaneously stored in a and 5b, the voltage across the smoothing capacitor 8 can be greatly increased.

The degree of this step-up is determined by the pulse signal control unit 22.
Increases in accordance with the increase in the pulse width of the pulse signal output by Thus, a voltage value from the full-wave rectified voltage to a value equal to or higher than the voltage doubled rectified voltage can be output.

In the following embodiments, the changeover switch section 12 is in the off state, the operation mode shown in FIG. 2 is "full-wave rectification mode", and the operation mode shown in FIG. 17 is "boost mode".
The operation mode shown in FIG. 3 in which the changeover switch unit 12 is in the ON state and the operation mode shown in FIG. 3 is called the "double voltage rectification mode".

When the voltage value Vin of the AC power supply 1 is 100 V, in the full-wave rectification mode, the voltage applied to the load 9 is the voltage Vdc across the smoothing capacitor 8, and is approximately 1
The value is around 40V.

Here, when the changeover switch section 12 is switched to the ON state and in the double voltage rectification mode, the power factor improving operation is maintained, but the voltage applied to the load 9 is approximately 280 V.
Therefore, the voltage value largely fluctuates from the voltage value before switching. Depending on the load 9, a problem may occur due to the sharp fluctuation of the applied voltage.

The present embodiment is intended to suppress the fluctuation of the output voltage generated when the energization state of the changeover switch section 12 is switched. This will be specifically described below.

When the power supply operates in the full-wave rectification mode, a larger applied voltage is required due to an increase in the load 9 and the like. At this time, the pulse signal control unit 22 changes the form of the pulse signal to be output, and improves the power factor and boosts the output voltage Vdc in the boost mode. The pulse signal control unit 22 expands the pulse width of the long and short pulse signals until the output voltage Vdc reaches a predetermined value (here, 280 V) in the boost mode. This output voltage Vdc is detected by a DC voltage detection unit (not shown) and output to the pulse signal control unit 22.

When the pulse signal control unit 22 confirms that the output voltage Vdc has reached 280 V, the pulse signal control unit 22
Is switched to the ON state to shift to the double voltage rectification mode. When the voltage value of the AC power supply 1 is 100 V,
The output voltage Vdc of the gate becomes approximately 280 V. Therefore, in this case, it is possible to sufficiently suppress the fluctuation of the output voltage caused by changing the energization state of the changeover switch unit 12.

Further, when the pulse width of the long pulse signal is fixed so as to be substantially equal to the half cycle of the AC power supply 1 in the boost mode, this is a voltage doubler rectification operation. When a short pulse signal is output to the other switching element,
Since the power factor improving operation is based on the voltage doubler rectification, the operation is exactly the same as that of the voltage doubler rectification mode.

In this state, as shown in FIG. 18, when the pulse width tp of the short pulse signal in the boost mode and the pulse width tp of the pulse signal in the voltage doubler rectification mode are equal, the two modes are exactly the same. Will work. Also, at this time, the values of the input current waveform and the output voltage Vdc in the two modes are completely equal. Further, in this case, the DC voltage detector is not required.

Therefore, when changing the energization state of the changeover switch section 12, the pulse signal control section 22 performs the voltage doubler rectification operation in the step-up mode, the pulse width of the time-short pulse signal and the voltage doubler rectification mode. By controlling the pulse widths of the pulse signals equally, it is possible to eliminate the waveform distortion of the input current and the fluctuation of the output voltage Vdc.

As described above, according to the power supply device of the present embodiment, in addition to the features that the structure and control are simple, a sufficient harmonic suppression effect can be obtained, and a low-loss power supply device can be provided. Thus, when the energization state of the changeover switch unit 12 is changed, a steep waveform distortion of the input current and a change in the output voltage Vdc can be sufficiently suppressed by using the boost mode. Therefore, since the specification specifications of the components can be reduced, the device can be downsized, and a highly reliable power supply device that can provide a stable output with little influence on the load 9 can be provided.

Further, by performing the voltage doubler rectification operation in the step-up mode, it is possible to eliminate the sharp waveform distortion of the input current and the fluctuation of the output voltage Vdc due to the switching of the changeover switch section 12. Therefore, it is possible to provide a very reliable power supply device that can further reduce the size of the device because the specification specifications of the components can be further reduced and can provide a stable output without affecting the load 9. it can.

(Embodiment 6) FIG. 19 is a circuit diagram showing still another embodiment of the power supply device according to the present invention.
19, the power supply device further includes a load state detection unit 27 in the circuit configuration shown in FIG.

In the present embodiment, the load state detecting section 27 includes a voltage Vdc across the smoothing capacitor 8 obtained from the DC voltage detecting section 26 and a load obtained from the load current detecting section 71 constituted by a resistor or a current transformer. The magnitude of the load 9 is calculated based on the current.

Hereinafter, the power supply device of FIG. 19 will be described in more detail. The pulse signal control section 22 switches the energization state of the changeover switch section 12 according to the size of the load 9 obtained from the load state detection section 27.

In FIG. 19, when the magnitude W of the load 9 detected by the load state detecting section 27 is equal to or smaller than the predetermined value Y1, the pulse signal control section 22 turns off the changeover switch section 12 to turn off the full-wave rectifying module. When the magnitude W of the load 9 is equal to or more than the predetermined value Y1, the changeover switch unit 12 is turned on to perform the power factor improvement by the voltage doubler rectification mode.

That is, if W ≦ Y1, the pulse signal control unit 22
Outputs pulse signals Pa and Pb shown in FIG. Also,
When W ≧ Y1, the pulse signal control unit 22 outputs the pulse signals Pa and Pb shown in FIG.

Thus, in a region where the load W is equal to or less than the predetermined value Y1, a high power factor can be obtained, and the output voltage can be kept substantially constant at a voltage obtained by the full-wave rectification. In addition, in a region where the load W is equal to or more than the predetermined value Y1, a high power factor can be obtained, and a voltage value larger than a voltage obtained by doubling the output voltage can be obtained. As a result, the output voltage can be largely changed according to the size of the load 9.

Further, by using the step-up mode as shown in FIG. 17 in the region of W ≧ Y1, the pulse width is increased in proportion to the size W of the load 9, and the output voltage can be obtained by full-wave rectification. It can be gradually changed from the voltage value to a voltage value larger than the voltage obtained by the voltage doubler rectification.

Further, another predetermined value Y2 is set,
When the size of the load 9 is equal to or less than Y2, both of the pulse signals may be turned off.

That is, when W ≦ Y2, the pulse signal control unit 22
Does not output a pulse signal. When Y2 ≦ W ≦ Y1, the pulse signal control unit 22 outputs the pulse signals Pa and P shown in FIG.
b is output. Further, when W ≧ Y1, the pulse signal control unit 22 outputs the pulse signals Pa and Pb shown in FIG. Here, the boost mode shown in FIG. 17 is used to increase the output voltage.
May be used.

As a result, in the above embodiment, the load 9
In a region where the size W is equal to or smaller than Y2, the switching element 4
Since there is no current conduction to the switching elements a and 4b, the loss in the switching element can be reduced, so that the loss of the device can be reduced.

As described above, according to the power supply device of the present embodiment, the magnitude W of the load 9 is compared with the predetermined value, and the operation mode to be output is changed according to the magnitude of the magnitude, thereby providing a high power factor over the entire load. Can be obtained, harmonic components can be suppressed, and the output voltage can be changed according to the size of the load 9. Further, the loss can be further reduced by turning off the pulse signal in a low load region.

As a result, even with respect to a load whose magnitude varies, the harmonic component can be suppressed in the entire variation range, and the output voltage can be varied.
Higher output can be realized.

Further, since the circuit configuration and the control are simple, the noise generated is small and the filter circuit can be simplified, and the loss in the switching means is small and the loss can be reduced.

The effect of the power supply device of the present invention is not limited to the switching pattern of the changeover switch section 12 shown in the present embodiment, but the power supply device of another invention as shown in the first to fifth embodiments. Further effects can be obtained by using in combination with.

In this embodiment, the load state detecting section 27 is obtained from the voltage across the smoothing capacitor 8 obtained from the DC voltage detecting section 26, and from the load current detecting section 71 constituted by a resistor or a current transformer. The magnitude of the load 9 is calculated from the load current. However, the load detection method in the power supply device of the present invention is not limited to this, and the detection method can be calculated from the output voltage, the output current, the input current, the current flowing through the switching element, the pulse width, and the like. Further, it can also be detected by calculating these in combination.

(Embodiment 7) FIG. 20 is a circuit diagram showing still another embodiment of the power supply device according to the present invention. FIG.
0, the power supply device includes an inverter device 10 and a motor device 11 as the load 9 in the circuit configuration shown in FIG. 1, and further includes a load state detection unit 27. The inverter device 10 is composed of a plurality of semiconductor elements, and converts the substantially DC voltage Vdc across the smoothing capacitor 8 into a variable voltage / variable frequency AC voltage by switching the semiconductor elements at a high frequency. As a semiconductor element, like the switching elements 4a and 4b of the power factor correction circuit 7, the power is
A self-extinguishing semiconductor such as a transistor, a power MOSFET and an IGBT is used. The variable voltage / variable frequency AC voltage output from the inverter device 10 is supplied to the motor device 11 for variable speed driving. In this embodiment, a DC brushless motor is used as the motor device 11.
Is used.

The load state detecting section 27 comprises an inverter control section 30, an inverter driving section 31, and a position detecting section 32. The position detecting section 32 is a motor device 11, that is, D
It detects the rotor position of the C brushless motor and outputs a position detection signal, and is composed of a hall sensor, an encoder, and the like. The inverter control unit 30 includes the position detection unit 3
2 generates and outputs a control signal for driving the inverter device 10 based on the position detection signal from the microcomputer 2, and is constituted by a microcomputer or the like. The inverter driving unit 31 drives the semiconductor elements of the inverter device 10 based on the control signal generated and output by the inverter control unit 30.

In the present embodiment, the motor device 1 is obtained from the detection interval of the position detection signal output from the position detection unit 32.
The magnitude of the load is detected based on the speed (1).

The pulse signal control section 22 generates and outputs a pulse signal for driving the switching elements 4a and 4b, and instructs the changeover switch drive section 40 to switch the energized state of the changeover switch section 12. In this example, the load state detected by the inverter control unit 30 which is a component of the load state detection unit 27 is also read.

Hereinafter, the power supply device shown in FIG. 20 will be described in more detail. The inverter control unit 30 receives a speed command signal from the outside and a position detection signal from the position detection unit 32 and controls the inverter device 10 to control the motor device 11 to a predetermined speed. Generate

Considering, for example, a compressor motor used for an air conditioner or the like as the motor device 11 that is driven at a variable speed by the inverter device 10, the compressor motor has a function corresponding to the magnitude of the speed. As a result, the load torque increases and the back electromotive voltage generated in the motor winding increases, so that the voltage and current applied to the motor device 11 increase, and the output power increases. Accordingly, the input power and input current of the AC power supply 1 also increase.

FIGS. 21, 22 and 23 show the energized state of the changeover switch section 12 with respect to the load, the control mode of the power factor improvement circuit 7, and the motor apparatus 1 using the inverter apparatus 10.
FIG. 3 is a diagram illustrating speed control 1;

In the control shown in FIG. 21, after the motor device 11 is started, the pulse signal control unit 22 turns off the changeover switch unit 12 to improve the power factor in the full-wave rectification mode. In this case, for example, if the voltage value of the AC power supply 1 is 200 V, the voltage Vdc across the smoothing capacitor 8 has a value of approximately 280 V.

The magnitude of the load increases as the speed of the motor device 11 increases. The pulse signal control unit 22 controls the pulse width of the pulse signal according to the magnitude of the load, that is, the speed of the motor device 11, so as to maximize the power factor or the efficiency.
During this time, the inverter control unit 30 controls the motor device 11 to a predetermined speed based on an external speed command signal, so that the pulse duration of the high-frequency pulse signal for driving each semiconductor element of the inverter device 10 is controlled. Inverter PWM (Pulse Width Mo) that controls the motor device 11 at a predetermined speed by controlling the motor and adjusting the voltage applied to the motor device 11.
dulation) control.

When the pulse duty of the high-frequency pulse signal output by the inverter control unit 30 reaches a predetermined value, for example, 100% with an increase in load, the voltage supply to the motor device 11 becomes saturated, The speed of the motor device 11 cannot be increased any more. Therefore, in order to improve the speed of the motor device 11, in order to supply a larger voltage, it is necessary to increase the output voltage of the power factor improving circuit 7, that is, the voltage Vdc across the smoothing capacitor 8. Therefore, hereinafter, the power factor improving circuit 7 by the pulse signal control unit 22
, The voltage V across the smoothing capacitor 8
Inverter that controls motor device 11 at a predetermined speed by controlling dc to adjust the voltage applied to motor device 11.
PAM (Pulse Amplitude Modulation) control is performed.

Next, another control method in this embodiment will be described with reference to FIG. In the control of FIG.
After the start-up of the power device 11, the pulse signal control means 22 turns off the changeover switch section 12 to improve the power factor in the full-wave rectification mode. In this case, for example, the voltage value of the AC power supply 1 is 1
If it is 00V, the voltage Vdc across the smoothing capacitor 8 has a value of about 140V.

As the speed of the motor device 11 increases, the magnitude of the load also increases. The pulse signal control unit 22 controls the pulse width of the pulse signal according to the magnitude of the load, that is, the speed of the motor device 11, so as to maximize the power factor or the efficiency.
During this time, the inverter control unit 30 performs inverter PWM control to control the motor device 11 at a predetermined speed based on an external speed command signal.

Then, as the load increases, the inverter device 1
When the pulse duty of 0 reaches a predetermined value, for example, 100%, the voltage supply to the motor device 11 becomes saturated, and the speed of the motor device 11 cannot be further increased.

Therefore, in order to improve the speed of the motor device 11 and supply a larger voltage, the output voltage of the power factor improving circuit 7, that is, the voltage Vdc across the smoothing capacitor 8 is required.
Need to be increased. The pulse signal control unit 22 changes the form of the output pulse signal and improves the power factor in the boost mode. In the step-up mode, the voltage V across the smoothing capacitor 8 is controlled by controlling the pulse width of two long and short pulse signals.
dc can be controlled in a wide range. In this step-up mode, an inverter PAM control for controlling the voltage Vdc to adjust the voltage applied to the motor device 11 and controlling the motor device 11 to a predetermined speed is performed.

When the speed of the motor device 11 is further increased and the voltage Vdc across the smoothing capacitor 8 is further increased accordingly, the pulse width of the two long and short pulse signals output by the pulse signal control section 22 is also increased. . When the pulse width of the long pulse signal is sufficiently widened to be equal to a half cycle of the AC power supply 1, the power supply device performs a voltage doubler rectification operation. At this time, the pulse signal control section 22 switches the changeover switch section 12 to the ON state as shown in FIG.
At this time, control is performed so that the pulse width of the pulse signal becomes equal to the pulse width of the short pulse signal immediately before switching.

As a result, the operation mode of the power supply device can be smoothly shifted from the boost mode to the voltage doubler rectification mode. The pulse signal control unit 22 can further increase the voltage Vdc across the smoothing capacitor 8 by expanding the pulse width of the pulse signal output in the voltage doubler rectification mode, so that the speed of the motor device 11 can be increased. Can be further increased. Further, in the voltage doubler rectification mode, the conduction loss of the semiconductor element can be suppressed as compared with the voltage doubler operation in the step-up mode. It can be carried out.

By switching these operation modes, 100 V
At the time of input, the same output voltage V as at the time of 200V input
dc can be obtained, and the motor device 11 can be obtained over a wider range.
Speed control can be performed.

In order to reduce the speed of the motor device 11 from the high-speed region to the low-speed region, control reverse to the above series of control may be performed.

The switching between the full-wave rectification mode and the boosting mode is not necessarily performed at the point where the pulse duty of the high-frequency pulse signal output from the inverter control means 30 becomes 100%. As shown in FIG. 23, the mode switching point may be different before and after the point where the pulse duty becomes 100%.

Further, by providing hysteresis at the switching point between the modes, it is possible to prevent the mode from being complicatedly changed due to unstable operation near the mode switching point.

Therefore, according to the power supply device of the present embodiment, in a region where the load on the motor device 11 is small, the power factor is improved and the inverter is improved in the full-wave rectification mode in which the changeover switch section 12 is turned off. In the load region where the DC voltage is saturated, the power factor is improved by the boost mode and the speed is controlled by the inverter PAM control. Further, in a region where the load is large, the power factor is improved by the voltage doubler rectification mode in which the changeover switch unit 12 is turned on, and the speed control is performed by the inverter PAM control. Therefore, a sufficient power factor can be obtained in the entire operation range of the motor device 11. Moreover, in the full-wave rectification mode, the output voltage of the power supply device is kept low to suppress iron loss in the motor device 11, and in the boost mode, the inverter PA
The switching loss of the inverter device 10 can be suppressed by the M control, and the conduction loss of the power supply device can be suppressed in the voltage doubler rectification mode.

Thus, a power supply capable of sufficiently suppressing the harmonic components of the input current over the entire operating range of the motor device 11 and driving the motor device 11 with high efficiency and high output over a wide range. The device can be realized. In addition, the noise generated is small with simple control, and an increase in loss in the filter circuit and the switching elements 4a and 4b can be suppressed.

In this embodiment, the form of the pulse signal output from the pulse signal control unit 22 and the changeover switch unit 1
The switching operation of No. 2 is not limited to this embodiment. Further, in the present embodiment, a DC brushless motor is used as the motor device 11, but the motor device 11 in the power supply device of the present invention is not limited to this, and may be an induction motor.
Similar effects can be obtained with other motor devices such as motors.

The configuration of the load state detector 27 is not limited to the configuration shown in FIG. In the present embodiment, the speed of the motor device 11 is used as a method of detecting the load state. However, the output pulse duty, the output frequency, the output current value of the inverter device 10 and the voltage applied to the motor device 11 are also used. Voltage, current, input current Iin, or the like. Further, the same effect can be obtained by detecting the magnitude of the load by a combination of these.

(Eighth Embodiment) FIG. 24 shows a configuration example of an air conditioner to which any of the power supply devices of the present invention is applied.
As shown in FIG. 24, the air conditioner uses the power supply device shown in the first embodiment as a converter device, and the inverter device 8
1. In addition to the electric compressor 82, a refrigeration cycle including an indoor unit 92, an outdoor unit 95, and a four-way valve 91 is provided.

The indoor unit 92 includes an indoor heat exchanger 93 and an indoor blower 94, and the outdoor unit 95 includes an outdoor heat exchanger 96, an outdoor blower 97, and an expansion valve 98.

During the refrigeration cycle, a refrigerant as a heat medium circulates. The refrigerant is compressed by the electric compressor 82, exchanges heat with outdoor air in the outdoor heat exchanger 96 by blowing from the outdoor blower 97, and in the indoor heat exchanger 93 by blowing air from the indoor blower 94. Heat exchange with. The indoor air is cooled and heated by the air after the heat exchange in the indoor heat exchanger 93. Switching between cooling and heating is performed by reversing the circulation direction of the refrigerant by the four-way valve 91. The circulation of the refrigerant in the refrigeration cycle as described above is performed by driving the electric compressor 82 by the inverter device 81, and the supply of electric power to the inverter device 81 and the electric compressor 82 is performed by the converter device. This is performed using the power supply device according to the first embodiment. The configuration and operation of the power supply device are as described above.

With the above configuration, it is possible to suppress harmonic components of the input current in the air conditioner. Also,
An air conditioner with low noise and low loss can be provided.

In this embodiment, the power supply device shown in Embodiment 1 is used as the converter device. However, the effects of each power supply device can be similarly obtained by using the other power supply devices shown in Embodiments 2 to 7. An air conditioner having the above can be provided.

In the power supply of the present invention, the AC power supply 1
By switching the energization state of the changeover switch section 12 even at V, harmonics can be suppressed and the size of the reactor 3 can be reduced. Therefore, the same reactor 3 as that at the time of 100V input can be used.

Further, even if the AC power supply 1 is 100 V, it is possible to suppress harmonics and obtain an output voltage higher than the voltage obtained by voltage doubler rectification. Therefore, even with a 100 V input, an output voltage equivalent to that at a 200 V input can be obtained without the need for a voltage doubler rectifier circuit.

In addition, by controlling the on / off of the changeover switch section 12, the pulse width and the pulse signal pattern in accordance with the size of the load, it is possible to obtain optimum output voltage, power factor and efficiency over the entire load. . Further, when switching the changeover switch section 12, there is no influence on the input current and the output voltage, and the size and reliability of the device can be improved.

Therefore, the power supply device of the present invention can be used in both 100 V and 200 V models, particularly for air conditioners, to obtain a high power factor and suppress harmonic components contained in the input current. Can be.

In addition, the circuit configuration and constituent parts can be shared, and the size of the device can be reduced. This has a very large effect that the number of development steps and the number of parts can be greatly reduced.

FIG. 25 shows a circuit configuration in which the values of the capacitors 5a and 5b are changed and the smoothing capacitor 8 is omitted in the power supply devices shown in the first to seventh embodiments.
In the power supply device having such a configuration, the same effects as those described above can be obtained.

[0151]

According to the first power supply device of the present invention, the current conduction period can be extended with a simple configuration and control, the harmonic component can be sufficiently suppressed, and the generated noise and noise can be reduced. It is possible to realize a power supply device in which loss is reduced.

According to the second power supply device of the present invention, the current conduction period can be extended by a simple configuration and control, harmonic components can be sufficiently suppressed, and generated noise and loss can be reduced. It can be kept low. Furthermore, even if the power supply voltage is 200 V, the reactor can be prevented from increasing in size, so that it is possible to realize a power supply device that can support a plurality of power supply systems using the same components.

According to the third power supply device of the present invention, the current conduction period can be extended by a simple configuration and control, harmonic components can be sufficiently suppressed, and generated noise and loss can be reduced. Can be suppressed. In particular, the power factor improving operation can be reliably performed by detecting the zero cross point of the power supply voltage, and the reliability can be improved. Furthermore, even if the power supply voltage is 200 V, the reactor can be prevented from increasing in size, so that the same component can be used for a plurality of power supply systems, and a power supply device capable of reducing the number of development steps can be realized. .

According to the fourth power supply device of the present invention, the harmonic components of the input current can be sufficiently suppressed by a simple configuration and control, and the generated noise and loss can be suppressed low. In addition, since the power factor can be reliably improved regardless of the connection position between the changeover switch and the rectifier circuit, the pulse signal is set after fixing the connection point of the changeover switch to one side or confirming the connection point. Therefore, it is possible to provide a power supply device that requires less installation man-hours and has high reliability, because it is possible to prevent troubles such as troubles caused by setting and the like and setting errors.

According to the fifth power supply of the present invention, it is possible to sufficiently suppress the harmonic component of the input current with a simple configuration and control, and to suppress the generated noise and the loss. Furthermore, it is possible to suppress sharp waveform distortion of the input current which occurs when the energized state of the changeover switch unit is switched, and it is possible to reduce the specification specifications of each component of the power supply device, so that the device can be downsized. And a highly reliable power supply device can be realized.

According to the sixth power supply device of the present invention, it is possible to sufficiently suppress the harmonic component of the input current with a simple configuration and control, and to suppress the generated noise and the loss. In addition, it is possible to suppress the steep waveform distortion of the input current generated when switching the energized state of the changeover switch unit without adding new parts, and to reduce the specification specifications of each component of the power supply device. Therefore, the power supply device can be further downsized, and a highly reliable power supply device can be realized.

According to the seventh power supply device of the present invention, it is possible to sufficiently suppress the harmonic component of the input current with a simple configuration and control, and to suppress the generated noise and the loss. Further, it is possible to sufficiently suppress a sharp waveform distortion of an input current and a fluctuation of an output voltage which are generated when the energization state of the changeover switch unit is switched, and it is possible to reduce the size of the device and to reduce the influence on the load and to increase the reliability. A power supply device can be realized.

According to the eighth power supply device of the present invention, it is possible to sufficiently suppress the harmonic component of the input current by a simple configuration and control, and to suppress the generated noise and the loss. Further, it is possible to eliminate sharp waveform distortion of the input current and fluctuation of the output voltage which occur when the energization state of the changeover switch unit is switched, and it is possible to greatly reduce the size of the device and have high reliability without affecting the load. A power supply device can be realized.

According to the ninth power supply device of the present invention, it is possible to sufficiently suppress the harmonic components over the entire range of fluctuation of a load whose magnitude varies, and to vary the output voltage. And higher output can be realized. Further, since the configuration and the control are simple, a power supply device capable of suppressing generated noise and loss can be realized.

According to the tenth power supply of the present invention, the
Since the operation mode is switched according to the magnitude of the load applied to the motor device, the harmonic component of the input current can be sufficiently suppressed in the entire operation range of the motor device, and a high efficiency and high output motor device can be provided. Driving can be performed. In addition, since the configuration and the control are simple, it is possible to realize a power supply device capable of suppressing generated noise and loss low.

According to the eleventh power supply device of the present invention, a pulsating component included in the DC voltage from the power factor improving circuit is eliminated by the smoothing capacitor, so that a higher quality DC voltage can be output.

According to the air conditioner of the present invention, an air conditioner having a high power factor, low harmonic components and low loss can be realized.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a power supply device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing pulse signals and main waveforms according to the first embodiment of the power supply device of the present invention.

FIG. 3 is a diagram showing pulse signals and main waveforms according to the first embodiment of the power supply device of the present invention.

FIGS. 4A to 4D are current path diagrams in one configuration example of the power supply device of the present invention.

5 (a) to 5 (d) are current path diagrams in another configuration example of the power supply device of the present invention.

FIG. 6 is a circuit configuration diagram in Embodiment 2 of the power supply device of the present invention.

FIG. 7 is a circuit configuration diagram in Embodiment 2 of the power supply device of the present invention.

FIG. 8 is a circuit configuration diagram according to Embodiment 2 of the power supply device of the present invention.

FIGS. 9A and 9B are a second embodiment of the power supply device of the present invention.
FIG. 4 is a pulse signal and main waveform diagram in FIG.

FIG. 10 is a diagram illustrating pulse signals and main waveforms according to a second embodiment of the power supply device of the present invention.

FIG. 11 is a diagram showing pulse signals and main waveforms in a power supply device according to a second embodiment of the present invention.

12A to 12D are current path diagrams in still another configuration example of the power supply device of the present invention.

FIG. 13 is a circuit configuration diagram in Embodiment 3 of the power supply device of the present invention.

FIG. 14 is a diagram illustrating pulse signals and main waveforms according to a third embodiment of the power supply device of the present invention.

FIG. 15 is a diagram illustrating pulse signals and main waveforms according to a third embodiment of the power supply device of the present invention.

FIG. 16 is a circuit diagram of a power supply device according to a fourth embodiment of the present invention.

FIG. 17 is a diagram illustrating pulse signals and main waveforms in a power supply device according to a fifth embodiment of the present invention.

FIG. 18 is a diagram showing pulse signals and main waveforms in a power supply device according to a fifth embodiment of the present invention.

FIG. 19 is a circuit configuration diagram in Embodiment 6 of the power supply device of the present invention.

FIG. 20 is a circuit diagram of a power supply device according to a seventh embodiment of the present invention.

FIG. 21 is a diagram showing the state of conduction of a changeover switch unit to a load;
The figure which showed the control mode of the power factor improvement circuit, and the speed control of the motor apparatus by an inverter apparatus.

FIG. 22 is a diagram showing an energized state of a changeover switch unit with respect to a load;
The figure which showed the control mode of the power factor improvement circuit, and the speed control of the motor apparatus by an inverter apparatus.

FIG. 23 is a diagram showing an energized state of a changeover switch unit with respect to a load;
The figure which showed the control mode of the power factor improvement circuit, and the speed control of the motor apparatus by an inverter apparatus.

FIG. 24 is a block diagram of a configuration showing an embodiment of the air conditioner of the present invention.

FIG. 25 is a diagram showing another configuration example of the power supply device of the present invention.

26A is a circuit configuration diagram showing an example of a conventional power supply device, and FIG. 26B is a main waveform diagram.

27A is a circuit configuration diagram showing another example of the conventional power supply device, and FIG. 27B is a main waveform diagram thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Rectifier circuit 2a, 2b, 2c, 2d Rectifier 3 Reactor 4a, 4b Switching 5a, 5b Capacitor 6a, 6b Backflow prevention rectifier 7 Power factor improvement circuit 8 Smoothing capacitor 9 Load 10 Inverter 11 Inverter device 12 changeover switch unit 21 zero-cross detection unit 22 pulse signal control unit 23 switch drive unit 26 DC voltage detection unit 27 load state detection unit 30 inverter control unit 31 inverter drive unit 32 position detection unit 40 changeover switch drive Unit 41 Voltage polarity discriminating unit 42 Input current detecting unit 43 Timer unit 71 Load current detecting unit 81 Inverter device 82 Electric compressor 91 Four-way valve 92 Indoor unit, 93 Indoor heat exchanger, 94 Indoor blower 95 Outdoor unit, 96 Outdoor Heat exchanger, 97 Outdoor blower 98 Expansion valve

Continued on the front page F term (reference) 3L060 AA03 EE04 5H006 AA02 BB05 CA01 CA07 CB01 CB04 CB08 CB09 CC08 DA04 DB01 DC04 DC05 5H007 AA02 BB06 CC12 DA06 DB01 DC02 DC05

Claims (12)

[Claims] 1. A rectifier circuit for rectifying an output voltage of an AC power supply and converting it to a DC voltage, (b) a reactor connected to the rectifier circuit, and (c) an output voltage of the rectifier circuit. A power factor improvement circuit, the power factor improvement circuit includes a plurality of switching elements connected in series, and a switching circuit that changes a current path of an input current flowing from the AC power supply by turning on and off; A switching circuit comprising: a capacitor circuit including a plurality of connected capacitors; and a backflow prevention rectifying element configured to prevent a charge charged in the capacitor from flowing back to the switching circuit when the switching circuit is on. A circuit and a capacitor circuit are arranged in parallel, a connection point between the switching elements and a connection point between the capacitors are connected, An end point of the switching circuit and an end point of the capacitor circuit are connected through the backflow prevention rectifier element, and (d) one of the input terminals of the rectifier circuit and a connection point between the switching elements of the power factor correction circuit. (E) switch control means for controlling the current-carrying state of the change-over switch means, the switch control means for controlling the current-carrying state of the current path formed between the current path and the current-carrying state. Pulse signal control means for generating and outputting a pulse signal for turning on / off each switching element of the power factor improvement circuit; and (g) receiving the pulse signal from the pulse signal control means, the switching circuit of the power factor improvement circuit. Switch driving means for driving the
A power supply device comprising: 2. A rectifier circuit for rectifying an output voltage of an AC power supply and converting it to a DC voltage, (b) a reactor connected to the rectifier circuit, and (c) an output voltage of the rectifier circuit. A power factor improvement circuit, wherein the power factor improvement circuit includes a plurality of switching elements connected in series, and is connected in series with a switching circuit that changes a current path of an input current flowing from the AC power supply by turning on and off. And a backflow prevention rectifying element for preventing a charge charged in the capacitor from flowing back to the switching circuit when the switching circuit is in an on state, the switching circuit comprising: And a capacitor circuit is arranged in parallel, a connection point between the switching elements and a connection point between the capacitors are connected, An end point of a switching circuit and an end point of the capacitor circuit are connected through the backflow prevention rectifier element, and (d) between one of the input terminals of the rectifier circuit and a connection point between the switching elements of the power factor correction circuit. (E) switch control means for controlling the current-carrying state of the change-over switch means, and (f) said force. Pulse signal control means for generating and outputting a pulse signal for turning on / off each switching element of the power factor improvement circuit; and the pulse signal control means comprising a plurality of switching elements of the power factor improvement circuit in a half cycle of the AC power supply voltage. A pulse signal for turning on at least one of them for a predetermined time, and a switching signal for switching an energized state of the changeover switch means. (G) switch driving means for receiving a pulse signal from the pulse signal control means and driving a switching circuit of the power factor correction circuit. . 3. A zero-cross detecting means for detecting a zero-crossing point of a power supply voltage and outputting a zero-crossing detecting signal, wherein the pulse signal control means performs the power factor correction based on the zero-crossing detecting signal from the zero-crossing detecting means. 3. The power supply device according to claim 2, wherein a pulse signal for turning on a switching element of the circuit for a predetermined time is output. 4. The apparatus according to claim 1, further comprising a voltage polarity determining unit configured to determine a polarity of the power supply voltage, wherein the pulse signal control unit refers to a determination result of the voltage polarity determining unit when at least the changeover switch unit is in a conductive state; The power supply device according to claim 2 or 3, wherein a pulse signal for turning on a switching element of the power factor correction circuit for a predetermined time according to a polarity in each half cycle of the power supply voltage is output. 5. An input current detecting means for detecting a current value of an AC power supply, wherein the pulse signal control means has a pulse signal in an OFF state and a current value obtained from the input current detecting means is zero. The power supply device according to any one of claims 2 to 4, wherein an energized state of the changeover switch means is switched at a time. 6. A zero-crossing detecting means for detecting a zero-crossing point of a power supply voltage and outputting a zero-crossing detecting signal, and a timer means for receiving a switching time signal after a lapse of a predetermined time in response to the zero-crossing detecting signal; 5. The power supply device according to claim 2, wherein the signal control means switches a power supply state of the changeover switch means in response to a changeover timing signal from the timer means. 7. The pulse signal control means turns on a plurality of switching elements of the power factor correction circuit for different predetermined times before and after switching the energized state of the changeover switch means when the changeover switch means is in a cutoff state. A first pulse signal is generated, and the output pattern of the first pulse signal is switched and output every half cycle of the AC power supply voltage, and the switching element of the power factor correction circuit is provided when the changeover switch is in a conductive state. A second pulse signal for turning on any one of them for a predetermined time, and outputting an output pattern of the second pulse signal every half cycle of the AC power supply voltage.
The power supply device according to any one of claims 2 to 6, wherein the power supply is switched and output. 8. The pulse signal control means outputs an ON time of a shortest pulse signal of the first pulse signals output when the changeover switch means is in a cut-off state, and outputs an output signal when the changeover switch means is in a conductive state. 8. The power supply device according to claim 7, wherein an on-time of the second pulse signal is made equal. 9. A load state detecting means for detecting a magnitude of a load, wherein the pulse signal control means conducts or cuts off the changeover switch means in accordance with the magnitude of the load obtained from the load state detecting means. 9. The power supply device according to claim 2, wherein the power supply is switched. 10. When the load comprises a motor device and an inverter device for converting a direct current to an alternating current in order to supply a driving voltage to the motor device, the load state detecting means includes the inverter. The power supply device according to claim 9, wherein a change amount generated due to a state change of the motor device or the motor device is detected. 11. The power supply device according to claim 1, further comprising a smoothing capacitor for smoothing an output voltage of the power factor correction circuit. 12. An air conditioner comprising the power supply device according to claim 1. Description: