JP2003018824A - Rectifier and rectifier method - Google Patents

Abstract

(57) [Problem] To obtain a rectified voltage having a good power factor and less noise. A switch element (13) connected between a rectifier element (12) and an inductance (16), a switch element (15) having one end connected between the inductance (16) and a diode (17), and the other end connected to the rectifier element (12). , One end of which is connected between the switch element 13 and the inductance 16 and the other end of which is connected to the capacitor 18.
And the control unit 19 controls the conduction of the switch element 13 and the switch element 15 so that the period during which the switch element 13 and the switch element 15 are in the conductive state is shorter than the period during which the switch element 14 is in the conductive state. The conduction of the switch element 14 is performed alternately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectifying device and a rectifying method for converting an alternating current into a direct current, and more particularly to a rectifying device and a rectifying method for improving a power factor.

[0002]

2. Description of the Related Art Consumer electronic devices such as radios and televisions are
Usually, it is equipped with a rectifying device for converting an alternating current generated in a power generation facility and supplied through a transmission line into a direct current, and the voltage of the current converted in the rectifying device is further transformed by a transformer to a desired value. And then get the power for operation.

As a rectifying device, a capacitor input type rectifying device is generally used from the viewpoint of reducing the size and weight of electronic equipment incorporating the rectifying device.

In recent years, various types of household electronic devices have appeared, and capacitor input type rectifiers have been widely used for these electronic devices. Furthermore, even in fluorescent lamps, electric washing machines, air-conditioning equipment, etc. that used AC current as it is, after converting AC to DC once, more efficient frequency power suitable for the characteristics of each electronic device. A capacitor input type rectifier circuit has also been used in an inverter system that is used after being converted into.

FIG. 12 shows a current waveform and a voltage waveform of the capacitor input type rectifier. FIG. 12A shows a current waveform and a voltage waveform of the half-wave rectifier circuit, and FIG.
(B) shows the current waveform and voltage waveform of the full-wave rectifier circuit. V _P indicates the peak point of the voltage value, and I _P indicates the peak point of the current value. Further, φ is a phase difference generated between the voltage waveform and the current waveform. In FIG. 12, the solid line is
The AC voltage is shown, and the broken line shows the rectified voltage after rectification. As shown in FIG. 12, the capacitor input type rectifier is generally characterized in that a current flows only near the peak value of the voltage.

[0006]

However, in the capacitor input type rectifier used in these electronic devices, the power factor in the device is extremely poor and a large amount of reactive power is generated. In addition, the amount of increase in current due to this reactive power becomes power loss in the power transmission line or the like.

As shown in FIG. 12, in the capacitor input type rectifier circuit, since electric power is supplied for a short period near the peak value of the voltage of AC power, the waveform of the supply voltage in the power supply line is disturbed. . In an electronic device designed on the assumption of a sine wave, the disturbance of the power waveform at this time may cause a malfunction.

Further, in the electric power transmission line, the amount of power loss radiated as Joule heat is pulsed to the case where the same electric power is sent to the electronic device evenly and to the case where the electronic device equipped with the capacitor input type rectifier is pulsed. In the latter case, the power consumption increases compared to when the power is sent.

The above-mentioned problems will be shown quantitatively. First, regarding the deterioration of the power factor in the capacitor input type rectifier circuit, even if only the fundamental wave is focused, the phase of the current precedes the phase of the voltage as shown in FIG. The power factor deteriorates according to the amount of advance of the phase.

Further, here, since the current is not a sine wave, many harmonics are generated. Strictly speaking,
The reactive power generated between the sinusoidal voltage and these harmonic currents will cause the power factor to deteriorate.

For the sake of simplicity, when the power factor is calculated only for the fundamental wave component ignoring the power factor deterioration due to the harmonic current,
The power factor is approximately represented by Expression (1). Power factor = active power / apparent power = Cosφ (1) where, apparent power = {(active power) ² + (reactive power) ² } ^1/2 , where φ is a voltage waveform and a current The phase difference between the waveform and the waveform is shown. The active power is the power actually consumed in the load (inside the electronic device) and is represented by the equation (2). Active power = apparent power * Cosφ (2) On the other hand, the reactive power is the power that reciprocates between the power supply side (power generation facility) and the power consumption side (electronic equipment), and is expressed by equation (3).
It is represented by. Reactive power = apparent power * Sinφ (3) When the power factor is bad, especially when the power factor is a value far from 1, the transmission and reception of power is not only performed in one direction from the power plant to the electronic device, From electronic devices (load devices) to power plants,
Alternatively, since it is performed for another electronic device, a large power supply capacity is required for the load capacity, which is inefficient.

Next, the influence of the disturbance of the waveform of the supply voltage on the power supply line will be described. As described above, in the capacitor input type rectifier, electric power is supplied only near the peak value of the voltage. for that reason,
When a large number of capacitor input type rectifiers are connected to the power supply line and the peak current is excessive, the voltage waveform on the power supply line is affected by the voltage drop due to the resistance component of the power supply line and is close to the peak value. Is crushed, the sine wave approaches a square wave, and the waveform becomes as shown in FIG.

When a motor or the like which is supposed to be driven by a sine wave is driven with such a waveform, a harmonic component thereof causes so-called power loss due to iron loss, resulting in overheating of the device or the like. Occurs.

A third factor is deterioration of the power factor due to copper loss. For example, consider a case where the same electric power is supplied to the load (electronic device) on average. When the resistance component of the power supply line is R, the loss when the current value is I and the current flow section is T and the loss when the current value is 2I and the current flow section is (1/2) T , And the average power loss over one period, the result is
As shown in. That is, the larger the peak current, the larger the power loss (copper loss).

[0015]

[Equation 1]

For these reasons, it is desired to improve the power factor of the rectifier. Conventionally, such power factor improvement in a capacitor input type rectifier circuit is disclosed in Japanese Patent Publication No. 60-4672 and Japanese Patent Laid-Open No. 6-54536.

FIG. 14 shows a configuration similar to that of the power factor correction converter disclosed in Japanese Patent Publication No. 60-4672. In the converter shown in FIG. 14, the AC voltage from the AC power supply 101 is full-wave rectified by the rectifier circuit 102, and then power is supplied to the switching regulator.

The switching regulator includes a transistor 104, an inductance 105, a capacitor 106,
And a diode 107, and a load 108
Power is being supplied to. The base of the transistor 104 is connected to the driver 126. Driver 126
Are supplied with an off signal 125 and an on signal 123.
The off signal 125 is generated in the magnetic flux detector 124 that detects the magnetic flux of the inductance 105, and the on signal 12 is generated.
3 is a voltage detector 1 for detecting the voltage of the capacitor 106.
21 and an instantaneous value detector 122 that detects the instantaneous value of the rectifier circuit 102.

According to what is disclosed in the patent publication, the operation of the converter having this structure is as follows. The magnetic flux detector 124 detects that the magnetic flux of the inductance 105 has become zero and generates the ON signal 123. Here, when the point where each element is commonly connected is regarded as the ground point, the capacitor 106 generates a negative voltage with respect to this ground point and is turned on according to the magnitude of the instantaneous value of the rectifier circuit 102. Time is controlled. As a result, the voltage of the capacitor 106 is stabilized. When the magnetic flux of the inductance 105 becomes substantially zero, the transistor 104 becomes conductive, and the current flows through the rectifier circuit 102. Therefore, the current does not flow only at the peak value of the voltage, and the power factor is improved.

However, in this configuration, when the common connection point with the capacitor 103, the inductance 105, and the capacitor 106 is defined as the ground point, the voltage at the other end of the capacitor 106 is only a negative value with respect to this ground point. It does not occur. In order to obtain a positive voltage, the negative side of the capacitor 106 can be considered to be the ground side of the device, but there are the following problems.

That is, one end of the power supply bus bar is generally grounded to the ground, while the ground on the device side is
It has a large capacitance to the ground side. In this case, through earth ground, rectifying element, diode, capacitance,
Since a loop called earth ground is formed and a noise current flows through this loop, this noise current may adversely affect other machines and electronic circuits of one's own.

FIG. 15 shows a circuit similar to the configuration disclosed in Japanese Patent Laid-Open No. 6-54536. In the device shown in FIG. 15, the current from the rectifier circuit 201 is detected by the current detector 206. Inductance 202, transistor 212, diode 203, capacitor 204
Constitutes a so-called step-up type switching regulator. The pulse width control unit 211 controls the transistor 212. Pulse width control unit 21
The input signal of 1 is the difference between the current detection unit 206 and the output voltage (reference numeral is not shown) of the rectifier circuit given through the resistor 209.

In this configuration, the current flowing through the rectifier circuit 201 is controlled based on the output voltage of the rectifier circuit, so that the power factor is expected to be improved. However, this method is a positive rectifier that obtains a positive voltage and cannot obtain a negative voltage.

Therefore, the present invention has been proposed in view of such a conventional situation, and a rectifying device and a rectifying method which prevent a power factor from being deteriorated and can obtain a rectified voltage with less noise are provided.
Another object of the present invention is to provide a rectifying device and a rectifying method that eliminate the risk of electric shock by disconnecting the load side from the AC power source side, and further, a rectifying device and a rectifying method that can handle both positive and negative polarities. And

[0025]

In order to achieve the above-mentioned object, a rectifying device according to the present invention rectifies an AC voltage from an AC power source by a rectifying means and makes the rectified output have an inductance and a predetermined polarity. A rectifying device that charges a capacitor via a diode connected accordingly and supplies a terminal voltage of the capacitor to a load, and is connected between a rectifying means and an inductance and switches between conduction and interruption of a rectified output. No. 1 switching means, one end is connected to the inductance and the diode, the other end is connected to the rectifying means, the second switching means, one end is connected to the first switching means and the inductance, and the other end is the capacitor. Third connected to
Of the first switching means and the second switching means such that the period during which the first switching means and the second switching means are in the conductive state is shorter than the period during which the third switching means is in the conductive state.
It is characterized by comprising control means for alternately executing conduction of the switching means and conduction of the third switching means.

According to such a rectifying device, the polarity of the current flowing from the inductance to the capacitor is switched by the third switching means. Also, by the control means,
The first switching means and the second switching means are conducted so that the period during which the first switching means and the second switching means are in the conducting state is shorter than the period during which the third switching means is in the conducting state. And conduction of the third switching means are performed alternately. Further, in this rectifying device, when the third switching means is a diode, the signal for controlling the third switching means becomes unnecessary.

Further, the control means performs control to change the period during which the first switching means and the second switching means are in the conductive state according to the voltage across the capacitor.

The rectifying device according to the present invention rectifies the AC voltage from the AC power source by the rectifying means and charges the rectified output to the capacitor through the inductance and the diode connected according to the predetermined polarity, In a rectifying device that supplies the terminal voltage of the capacitor to a load, a first switching unit that is connected between the rectifying unit and the inductance and switches between conduction and interruption of the rectified output, and one end thereof is connected to the inductance and the diode. , Second switching means having the other end connected to the rectifying means, third switching means having one end connected to the first switching means and the inductance, and the other end connected to the capacitor, the rectifying means and the capacitor The fourth switching means for switching between conduction and interruption between the third switching means and the first switching means and the second switching means are in the conductive state, and the third switching means is in the conductive state. As it is shorter than a period of time, perform the conduction of the conduction and the third switching means of the first switching means and second switching means alternately and conduction of the third switching means,
It is characterized by further comprising control means for controlling the third switching means and the fourth switching means so that the conduction between the rectifying means and the capacitor is executed at the same time.

According to such a rectifying device, in the control means, the period during which the first switching means and the second switching means are in the conductive state is shorter than the period during which the third switching means is in the conductive state. Then, the conduction of the first switching means and the second switching means and the conduction of the third switching means are alternately executed, and the conduction of the third switching means and the conduction between the rectifying means and the capacitor are performed. The third switching means and the fourth switching means are arranged to be executed simultaneously.
And the switching means are controlled.

Further, the rectifying method according to the present invention rectifies an AC voltage from an AC power source in a rectifying step, and charges the rectified output to a capacitor through an inductance and a diode connected according to a predetermined polarity. In the rectification method of supplying the terminal voltage of the capacitor to the load, first switching means for switching conduction and interruption of one rectification output from the rectification step, and conduction and interruption of the other rectification output from the rectification step. And an energy storage step of storing energy in the inductance by causing a rectified output to flow in the inductance via a second switching means, and the energy stored in the energy storage step is converted into a current according to a predetermined voltage polarity. Energy to be discharged to the capacitor through the third switching means for switching to discharge to the capacitor as The first switching means and the second switching means such that the period during which the first discharging means and the second switching means are in the conducting state is shorter than the period during which the third switching means is in the conducting state. It is characterized in that it has a control step for alternately executing conduction of the switching means and conduction of the third switching means.

According to such a rectifying method, the period during which the first switching means and the second switching means are in the conductive state is shorter than the period during which the third switching means is in the conductive state.
The conduction of the first switching means and the second switching means and the conduction of the third switching means are alternately controlled.

Further, according to the rectification method of the present invention, the AC voltage from the AC power source is rectified by the rectification means, and the rectified output is charged into the capacitor through the inductance and the diode connected according to the predetermined polarity. In the rectification method of supplying the terminal voltage of the capacitor to the load, first switching means for switching conduction and interruption of one rectification output from the rectification means, and conduction and interruption of the other rectification output from the rectification step. And an energy storage step of storing energy in the inductance by causing a rectified output to flow in the inductance via a second switching means, and the energy stored in the energy storage step is converted into a current according to a predetermined voltage polarity. And a third switching means for switching to discharge to the capacitor as an electric current, and conduction between the rectifying means and the capacitor. An energy discharging step of discharging a current to the capacitor through the fourth switching means for switching between disconnection and the third switching means during the period when the first switching means and the second switching means are in the conductive state. The conduction of the first switching means and the second switching means and the conduction of the third switching means are alternately executed so that the period becomes shorter than that in the state, and the conduction of the third switching means and the rectification means are performed. It is characterized by including a control step of controlling the third switching means and the fourth switching means so that the conduction between the capacitor and the capacitor is simultaneously executed.

According to such a rectification method, the period during which the first switching means and the second switching means are in the conductive state is shorter than the period during which the third switching means is in the conductive state.
Conduction of the first switching means and the second switching means and conduction of the third switching means are alternately executed, and conduction of the third switching means and conduction between the rectifying means and the capacitor are simultaneously performed. Thus, the third switching means and the fourth switching means are controlled.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION A rectifying device shown as a specific example of the present invention rectifies an AC voltage from an AC power source by a rectifying element and connects the rectified output with an inductance and a diode connected in accordance with a predetermined polarity. A rectifying device that charges a capacitor via a capacitor and supplies a terminal voltage of the capacitor to a load, the first switching device being connected between a rectifying element and an inductance and switching between conduction and interruption of a rectified output, A second switch element having one end connected to the inductance and the diode and the other end connected to the rectifying element, one end connected to the first switch element and the inductance, and the other end connected to the capacitor Of the first switch element and the second switch element are shorter than the third switch element in the conductive state. As such, a control unit for executing the continuity of the continuity and the third switch element of the first switching element and second switching elements alternately.

According to such a rectifier, electric power is stored in the inductance as magnetic flux energy for a predetermined period. That is, the magnetic flux energy is stored in the field as electromagnetic energy.

When the energy stored in the inductance is discharged, the energy for discharging is once stored in the capacitor through the diode whose one end is connected to the inductance and the other end is connected to the capacitor. By connecting the terminal of the inductance that is not connected to the diode when discharging energy from the inductance to the point where the potential for the load is the lowest, the voltage across the inductance is transferred after all the energy from the inductance has been transferred to the capacitor side. Are equal.

Therefore, the potential of the capacitor connected to the other end of the diode is always higher than the potential of the diode side terminal of the inductance. Since no current flows and the voltage at the other end of the inductance is connected to the point with the lowest potential, the diode side terminal of the inductance and the voltage at the other end of the inductance are at the same potential. Therefore, after the energy transition, the diode is reverse biased and always maintains the cutoff state. However, no current or charge transfer occurs thereafter.

Therefore, the voltage across the capacitor can be set to a voltage lower than the peak voltage value of this rectifier.

Furthermore, the rectifying device shown as a specific example of the present invention controls the amount of energy stored in the inductance by adjusting the value of the current supplied to the inductance according to the electric power generated by the load connected to the capacitor. This allows the voltage across the capacitor to be maintained at a desired constant value. In this way, if the period during which the current flowing from the AC power supply to the inductance flows is kept constant, a current proportional to the rectified voltage flows, so the voltage and the current are always in a proportional relationship, and the power factor is almost 1 Can hold

However, at this time, in order to move all the energy stored in the inductance to the capacitor,
Until the predetermined period has elapsed, no further current is supplied to the inductance from the AC power supply side. Moreover, since the energy stored in the inductance is released as a current, the reference point of the voltage can be set arbitrarily. Therefore, there is no problem even if the terminal voltage of the side of the inductor that is not connected to the diode is used as a reference point and the terminal voltage is lower than the voltage of the capacitor.

In order to use any one end of the inductance as a reference point, it is necessary to connect the relevant terminal of the inductance to a predetermined reference point. This is a switch for a mechanical relay or the like when the frequency is low. When a device is used and the frequency is high, an electronic switching device, for example, a transistor, FET, GTO (Gate Turn-Off Thyristo)
r), IGBT (Insulated Gate Bipolar Transisto)
r), can be realized by using an electronic switch element such as a thyristor. Further, it can be realized by changing the connection point of the inductance terminal by an on / off action having a semiconductor element such as a diode.

The first embodiment of the present invention will be described below with reference to FIG. A rectifying device 1 shown as a first specific example includes a rectifying element 12 connected to an AC power source 11 and
Individual switch elements 13, switch elements 14 and 15, an inductance 16, and a diode 17
It is provided with a capacitor 18, and a controller 19, and converts an alternating current from the alternating current power supply 11 into a direct current and supplies the direct current to the load 20.

In the rectifying device 1, the rectifying element 12 performs full-wave rectification on the alternating current and converts it into a so-called pulsating current.
In FIG. 1, the full-wave rectifier circuit is shown, but in this specific example, even a half-wave rectifier circuit operates without problems. As the switch element, either a semiconductor or a mechanical switch can be used, but when using a semiconductor switch element, it is necessary to select the polarity in advance according to the current direction. In addition, in the drawing, although it is described as a switch having one circuit and two contacts, the off side is not used.

Switch elements 13 to 15
Is controlled by the control unit 19 and is turned on and off.
Take one of the states. The switch element 13 and the switch element 15 are turned on or off at the same time. here,
The ON state means that the common terminal of the switch is A in FIG.
And the off state is defined as the state in which the common terminal of the switch is connected to the B side. When the switch element 13 and the switch element 15 are in the ON state, the control unit 19 constantly controls the switch element 14 so as not to be in the ON state. When the switch element 13 and the switch element 14 are turned on at the same time,
This is because an excessive current flows from the switch element 13 through the switch element 15.

When the switch element 13 and the switch element 15 are in the ON state, the rectifying element 12 to the inductance 16
Current is supplied to. This current energy is not consumed in the ideal inductance having a resistance value of 0, but is entirely stored.

Generally, the ideal inductance is defined as an element having a resistance value of zero, a predetermined inductance value, and no magnetic saturation. In the actual inductance, copper loss occurs in the resistance component.

[0047] here, the value of the inductance is L, the voltage of the rectifier circuit and _{E 0,} and the current flowing through inductance 16 and _{I L,} the value of _{I L} is represented by the formula (5).
Here, if τ is a period sufficiently shorter than the AC cycle T of the AC power supply 11, the value of E ₀ can be treated as a constant value during the period of τ. In addition, during the τ period, the value L of the inductance can also be treated as a constant value without magnetic saturation.

[0048]

[Equation 2]

[0049] Therefore, the value of _{I L,} as shown in equation (5), depends on the value of _{E 0} and the time elapsed t. In Figure 2, E
₀ and the relationship between the elapsed time t, and shows the relationship between I _L and the time t. After the time τ has elapsed, the switch elements 13 and 15 are turned off and the switch element 14
When is turned on, this stored energy is released. Since the magnitude of the current is continuous, energy is released to the capacitor 18 via the diode 17, drawing the same curve as it was stored. After a further τ time, the energy release is complete and the current becomes zero. Here, assuming that the load 20 is not connected, the increase amount ΔQ of the charge amount in the capacitor 18 is calculated by the equation (6).
Given in.

[0050]

[Equation 3]

Further, in the following equation (7), time
With the final value of t kept at a fixed value τ, after τ
The current I flowing out from the AC power supply is obtained. In formula (5)
E ₀The value of is expressed by equation (7) in full-wave rectification.
Time function V_RBecomes Where V_mVoltage amplitude maximum value
Then, the value of the current I becomes the value shown in the equation (8).

[0052]

[Equation 4]

[0053] Further, as is apparent from equation (9) below, when the value of τ is constant, the current I, voltage V _R
Flows in proportion to. This means that the power factor is 1 when viewed from the power supply side. On the other hand, the voltage across the capacitor 18 increases by the amount represented by the equation (9).

[0054]

[Equation 5]

As can be seen from the equation (9), τ is large,
The greater the energy stored in the inductance 16, the higher the voltage across the capacitor 18. Here, if the capacitance of the capacitor 18 is selected to be sufficiently large, ΔV
The amount of so-called ripple voltage represented by is sufficiently small and can be regarded as a substantially constant voltage.

The other end of the capacitor 18 is connected to the switch element 14 as the third switch element. When the on / off state of the switch element 14 is selected so that the output has a positive polarity, the switch element 14 and the capacitor 18
Since the connection point with is always the lowest potential against the load,
The voltage supplied to the load can be set to any value between 0 V and the peak value of the rectified voltage. Similarly, even when the negative polarity is selected, it can be set to any value between 0 V and the peak value of the rectified voltage.

Since the current flowing through the inductance 16 has a similar shape to the voltage, the power factor is always maintained at about 1. Furthermore, in this rectifying device, either the primary side and the device ground side are connected, or the above-mentioned noise loop is broken by the switch element 14, so the influence of noise can be reduced. .

As described above, in the rectifier 1 described above, the potential of the capacitor 18 is selected by selecting the value of τ.
It can be arbitrarily set between 0 V and the approximately peak value of the AC voltage. Also, at this time, the power factor becomes 1.

In the rectifying device 1 shown as the first specific example, the switch element 14 is connected to the rectifying element 12, but it may be separated from the rectifying element 12. The rectifying device 1a shown in FIG. 3 is a modification of the rectifying device 1 and has a configuration in which the rectifying element 12 and the switch element 14 are separated. According to this configuration, the load-side ground is separated from the primary side, so that the load-side ground can be independently provided. Since the rectifying device 1a has the same configuration as the rectifying device 1, components having the same function are denoted by the same reference numerals and detailed description thereof will be omitted.

Therefore, also in the rectifier 1a, similarly, by selecting the value of τ, the power factor is set to approximately 1, and the potential of the capacitor 18 can be arbitrarily set from 0 V to approximately the peak value of the AC voltage. Also, noise can be suppressed.

Next, regarding the second embodiment of the present invention,
This will be described with reference to FIG. The rectifier 2 shown as the second specific example is an example in which the switch element 14 in the rectifier 1 is replaced with a diode. The other components of the rectification device 2 are the same as those of the rectification device 1, and therefore, the same numbers are given and detailed description thereof is omitted.

When the switch element 14 is replaced with the diode 21, when the switch element 13 is connected to the B side, a current path for discharging energy of the inductance 16 is formed, and therefore the conductive state is maintained as long as energy discharging continues. Keep on maintaining. Therefore, it can be turned on / off substantially without a control signal.

Therefore, according to the rectifier 2 shown as the second specific example, by selecting the value of τ, the power factor is set to about 1, and the potential of the capacitor 18 is changed from 0V to about the peak value of the AC voltage. It can be set arbitrarily in between, and noise can be suppressed. Further, since it is not necessary to control the on / off timing of the switch element 14 by the control unit 19, there is an advantage that the configuration can be simpler and the manufacturing cost can be reduced.

In the second specific example, the switch element 14 is connected to the rectifying element 12, but it may be separated from the rectifying element 12. The rectifying device 2a shown in FIG. 5 is a modification of the rectifying device 2 and has a configuration in which the rectifying element 12 and the diode 21 are separated. According to this configuration, since the reverse bias is always applied when the switch element 13 is on, the diode 21 is off, and the diode 21 is on only when the switch element 13 is off. Therefore, the secondary side ground can be separated from the primary side.
The rectifying device 2a has the same configuration as the rectifying device 2, and thus detailed description of each component is omitted.

Therefore, according to the rectifier 2a, by selecting the value of τ, the power factor can be set to about 1, and the potential of the capacitor 18 can be arbitrarily set from 0 V to about the peak value of the AC voltage. Noise can be suppressed. Further, since it is not necessary to control the on / off timing of the switch element 14 by the control unit 19, there is an advantage that the configuration can be simpler and the manufacturing cost can be reduced.

Next, a third specific example of the present invention will be described with reference to FIG. The rectifier 3 shown in FIG.
This is an example of the case where the voltage across both ends of 8, that is, the voltage supplied to the load 20 is maintained at a predetermined value.

In the rectifying device 3, as a concrete configuration of the control section 19, a reference signal generating section 31, a signal comparing section 32,
It has a load voltage detector 33, a PWM modulator 34, and a switch element controller 35.

In the control unit 19, the reference signal generation unit 31
Generates a preset reference signal 41 and supplies it to the signal comparison unit 32. The load voltage detection unit 33 uses the capacitor 1
The potential V _c 42 at both ends of 8 is input, and the detection load voltage 43 is supplied to the signal comparison unit 32. The signal comparison unit 32 compares the reference signal 41 and the detected load voltage 43, and supplies the comparison signal 44 to the PWM modulation unit 34. PWM modulator 34
Supplies the PWM modulation signal 45 to the switch element controller 35. The switch element control unit 35 includes the switch element 13
To the control signal 46 to the switch element 15
To supply.

The reference signal 41 is a reference signal that the voltage supplied to the load 20 follows, and may be a signal that changes in time set in advance or a signal having a predetermined constant value. Good.

The detected load voltage 43 is the load voltage detection unit 33.
Potential V _c 42 across capacitor 18 detected by
Is a voltage that has been subjected to processing such as voltage division and filtering, and is used for calculation in the signal comparison unit 32.

The signal comparison unit 32 detects the difference between the reference signal 41 and the detected load voltage 43, and the signal of this difference is compared signal 4
4 is sent to the PWM modulator 34.

The PWM modulation section 34 generates a PWM modulation signal 45 based on the comparison signal 44 from the signal comparison section 32. As the PWM modulator included in the PWM modulator 32, a general-purpose modulator using a triangular wave or a sawtooth wave can be used.

The switch element control section 35 generates control signals 46 to 48 for controlling a switch opening / closing period τ described later in accordance with the characteristics of each element.

FIG. 7A shows the operation waveforms of the switch elements 13 and 15 in the on / off state when the reference signal 41 is constant, and FIG. 7B shows the reference signal 41. The operation waveform of the on / off state of the switch element 14 when it is constant is shown.

The period in which the switch elements 13 and 15 are in the ON state is indicated by τ. However, it is assumed that the value of τ is equal to or less than half (one half cycle) of one switching cycle τ _s of the switch. This is because when the period of τ exceeds a half cycle of one switching cycle of the switch, the current continues to flow in the inductance and the effect of improving the power factor is impaired. Also, since the ON / OFF operation of each switch is performed while the current is still flowing, the power loss increases.

In the rectifying device 3, the value of τ increases as the load current increases, and the current is supplied to the load 20 via the inductance 16 under the condition that the switching elements are accurately controlled. The switch element 14 may be turned on after the τ period has elapsed and turned off again after the period τ required for energy storage. However, as shown in FIG. 7, even if the switch element 14 continues to be turned on until the start of the next cycle, it operates. The above problem does not occur. Further, if the period in which τ changes is sufficiently large with respect to the period T of the pulsating flow after rectification, the power factor will not deteriorate. As described above, under the condition that τ changes gently, the voltage supplied to the load 20 is set to a predetermined value by sufficiently increasing the capacitance of the secondary-side capacitor 18 and reducing the ripple voltage with respect to the load current. Can be maintained at.

It is also possible to use a diode as the switch element 14 as in the example shown in FIG. In this case, the control signal 24 becomes unnecessary. Also, D
Using a SP (Digital Signal Processor), the signal comparison unit 32, the reference signal generation unit 31, and the PWM modulation unit 34
It is also possible to cause the DSP to execute the functions of the respective configurations and omit these configurations.

Next, a fourth specific example will be described with reference to FIG. In the rectifying device 4 shown in FIG. 8, components having the same functions as those of the rectifying devices 1 to 3 are designated by the same reference numerals and detailed description thereof will be omitted. In FIG. 8, the primary side is indicated by a thin line and the secondary side is indicated by a thick line. Here, the primary side is defined as all points connected to the terminals of the rectifying element 12, and the secondary side is defined as all points connected to the terminals of the capacitor 18.

In the fourth specific example, when the energy stored in the inductance is released, the reference potential point can be arbitrarily set. Therefore, it is possible to provide the voltage reference point at a point completely separated from the rectifying element. Therefore, the AC side and the load side can be separated, and electric shock can be prevented.

In this case, there is no problem even if the terminal on the side of current supply from the rectifying element to the inductance is used as the voltage reference point after the energy storage operation. As a result, since the polarity of the current flowing into the capacitor can be changed, the polarity of the output voltage can be reversed, and the AC side and the load side can be separated, and electric shock can be prevented.

Specifically, the rectifying device 4 includes the switch element 1
4 is characterized in that it has a switch element 22 controlled together with 4. The rectifying device 4 performs an operation of storing energy in the inductance 16 when the switch element 13 and the switch element 15 are turned on, and from the inductance 16 to the capacitor 18 when the switch element 14 and the switch element 22 are turned on. To release energy to. The operation waveform of each switch element of the rectifier 4 is
By replacing the operation of the switch element 14 in the rectifier 3 with the operation of the switch element 14 and the switch element 22 in the rectifier 4, the operation can be explained using the operation waveform diagram of each switch element shown in FIG. 7.

That is, assuming that the period in which the switch elements 13 and 15 are in the ON state is τ, the value of τ must be equal to or less than half (one half cycle) of one switching cycle τ _s of the switch. Under the control of the switch element accurately, the value of τ increases as the load current increases, and the current is supplied to the load 20 via the inductance 16. The switch element 14 and the switch element 22 may be turned on after the τ period has elapsed and turned off again after the period τ required for energy storage. However, even if the switch element 14 and the switch element 22 are kept on until the start of the next cycle, there is a problem in operation. Does not occur.

The diode 17 prevents a current from being emitted from the capacitor 18 toward the inductance 16 after all the energy of the inductance 16 is emitted.

In the specific example described above, the switch element 1
3 and the switch element 15, and the switch element 14 and the switch element 22 are not all turned on at the same time. Therefore, the capacitor 18 and the load 20 are connected by the switch element 14 and the switch element 22 to the AC power supply 1
It is completely electrically separated from 1.

Therefore, in the rectifying device 4 shown as the fourth specific example, by selecting the value of τ, the power factor is set to approximately 1, and the potential of the capacitor 18 is set between 0 V and the approximately peak value of the AC voltage. It can be set arbitrarily and noise can be suppressed. Further, even if the primary side is a commercial AC100V power source and the secondary side may come into contact with the human body, there is no danger of electric shock and the safety is high.

Next, a fifth specific example of the present invention will be described with reference to FIG. The rectifying device 5 shown as the fifth specific example has the same configuration as the rectifying device 4, but the rectifying device 4 generates a positive voltage, whereas the rectifying device 5 reverses the polarity to generate a negative voltage. The point of generation is characteristic. In the rectifying device 5 shown in FIG. 9, the components having the same functions as those of the rectifying devices 1 to 3 are designated by the same reference numerals and detailed description thereof will be omitted.

Therefore, according to the rectifying device 5, by selecting the value of τ, the power factor can be set to approximately 1, and the potential of the capacitor 18 can be arbitrarily set from 0 V to approximately the peak value of the AC voltage. Noise can be suppressed. Furthermore, since the secondary side can be configured symmetrically with the positive power source, the circuit arrangement and the like can be symmetrical, and the circuit design can be simplified. In addition, since the substrate can be shared between the case where the positive voltage is generated and the case where the negative voltage is generated, the manufacturing cost can be saved.

Next, a sixth specific example of the present invention will be described with reference to FIG. Rectifier 6 shown as a sixth specific example
Has a configuration similar to that of the rectifying device 5, but is characterized in that a positive voltage and a negative voltage can be taken out by using one inductance, and the primary side and the secondary side can be separated. . In the rectifying device 6 shown in FIG. 10, configurations having the same functions as those of the rectifying devices 1 to 3 are designated by the same reference numerals and detailed description thereof will be omitted.

The rectifying device 6 includes a diode 17a, a capacitor 18a, and a load 20a as a circuit for generating negative power. At this time, the on / off state of the switch element from the switch element controller 35 in the controller 19 is shown in FIG. FIG. 11A shows the switch element 1.
3 shows the control signals of the ON / OFF state of the switch element 15 and FIG. 11B, and FIG. 11B shows the control signals of the ON / OFF state of the switch element 14 and the switch element 22.
(C) has shown the control signal of the ON / OFF state of the switch element 23 and the switch element 24.

Since the rectifying device 6 can take out positive and negative voltages by using one inductance, the device can be downsized. Further, the primary side and the secondary side can be separated.

At this time, the on-state times of the switch elements 13 and 15 differ depending on the positive load and the negative load, and the amount of energy stored in the inductance also varies depending on the load power.

The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.
For example, by using the rectifiers of the above-described specific examples in combination, positive and negative voltages can be stably supplied regardless of load fluctuations.

[0093]

As described above in detail, the rectifying device according to the present invention rectifies the AC voltage from the AC power source by the rectifying means, and connects the rectified output with the inductance according to the predetermined polarity. In a rectifying device that charges a capacitor via the, and supplies a terminal voltage of the capacitor to a load, a first switching device that is connected between the rectifying device and the inductance and that switches between conduction and interruption of the rectified output, A second switching means having one end connected to the inductance and the diode and the other end connected to the rectifying means, and one end connected to the first switching means and the inductance and the other end connected to the capacitor. Of the first switching means and the first switching means and the second switching means are in a conducting state for a shorter period of time than the third switching means is in a conducting state. And a control means for performing alternately and conduction of the conduction and the third switching means of said second switching means.

Such a rectifying device is controlled by the control means.
The first switching means and the second switching means are conducted so that the period during which the first switching means and the second switching means are in the conducting state is shorter than the period during which the third switching means is in the conducting state. And conduction of the third switching means are performed alternately.

Therefore, according to the rectifying device of the present invention, since the polarity of the current flowing from the inductance to the capacitor is switched by the third switching means, both positive and negative voltages with respect to the load are applied. It is possible to supply.

Since the contact between the third switching means and the capacitor is always at the lowest potential with respect to the load, the voltage supplied to the load can be set to any value from 0V to the peak value of the rectified voltage.

Further, in the rectifier according to the present invention, the power factor can always be maintained at approximately 1 because the current waveform through which the inductance flows is similar to the voltage waveform.

Further, in the rectifying device according to the present invention, when the third switching means is a diode, a signal for controlling the third switching means is unnecessary, so that the device can be simplified and the manufacturing cost can be reduced. You can

In the rectifying device according to the present invention, the control means controls the period during which the first switching means and the second switching means are in the conductive state in accordance with the voltage across the capacitor. The voltage can be kept constant even if the load current changes. Further, there is an advantage that a voltage according to a predetermined target value that changes with time can be supplied regardless of fluctuations in the load current.

Further, the rectifying device according to the present invention rectifies the AC voltage from the AC power source by the rectifying means, and charges the rectified output to the capacitor through the inductance and the diode connected according to the predetermined polarity. In the rectifying device that supplies the terminal voltage of the capacitor to the load, the first switching means is connected to the rectifying means and the inductance and switches between conduction and interruption of the rectified output, and one end is connected to the inductance and the diode. , Second switching means having the other end connected to the rectifying means, third switching means having one end connected to the first switching means and the inductance, and the other end connected to the capacitor, the rectifying means and the capacitor The fourth switching means for switching between conduction and cutoff between the third switching means and the first switching means and the second switching means are in the conductive state, and the third switching means is in the conductive state. As is shorter than that period, the first
Of the switching means and the second switching means and the conduction of the third switching means are alternately executed, and the conduction of the third switching means and the conduction between the rectifying means and the capacitor are simultaneously executed. Thus, the control means for controlling the third switching means and the fourth switching means is provided.

In this rectifying device, in the control means, the first switching means and the second switching means are arranged so that the period during which they are in the conducting state is shorter than the period during which the third switching means is in the conducting state. Of the switching means and the second switching means and the conduction of the third switching means are alternately executed, and the conduction of the third switching means and the conduction between the rectifying means and the capacitor are simultaneously executed. Thus, the third switching means and the fourth switching means are controlled.

Therefore, according to the rectifying device of the present invention, since the polarity of the current flowing from the inductance to the capacitor is switched by the third switching means, both positive and negative voltages with respect to the load are applied. It is possible to supply.

Since the contact between the third switching means and the capacitor is always at the lowest potential with respect to the load, the voltage supplied to the load can be set to any value from 0V to the peak value of the rectified voltage.

Further, in the rectifier according to the present invention, the power factor can always be maintained at about 1 because the current waveform through which the inductance flows has a similar shape to the voltage waveform.

Further, in the rectifying device according to the present invention, when the third switching means is a diode, a signal for controlling the third switching means is unnecessary, so that the device can be simplified and the manufacturing cost can be reduced. You can

In the rectifying device according to the present invention, the control means controls the period during which the first switching means and the second switching means are in the conductive state in accordance with the voltage across the capacitor. The voltage can be kept constant even if the load current changes. Further, there is an advantage that a voltage according to a predetermined target value that changes with time can be supplied regardless of fluctuations in the load current.

Further, according to the rectifying device of the present invention, by providing the fourth switching means newly, it becomes possible to control conduction and interruption between the rectifying means and the capacitor in the device. Since the primary side (rectifying means) and the secondary side (capacitor) can be insulated without using a separate transformer, the power factor is improved, arbitrary polarity is selected, and the voltage from 0V as an absolute value to the peak value of the AC waveform. In addition to
It is possible to prevent electric shock.

Further, the rectifying method according to the present invention rectifies the AC voltage from the AC power source in the rectifying step, and charges the capacitor with the rectified output through the inductance and the diode connected according to the predetermined polarity. In the rectification method of supplying the terminal voltage of the capacitor to the load, first switching means for switching conduction and interruption of one rectification output from the rectification step, and conduction and interruption of the other rectification output from the rectification step. And an energy storage step of storing energy in the inductance by causing a rectified output to flow in the inductance via a second switching means, and the energy stored in the energy storage step is converted into a current according to a predetermined voltage polarity. Energy to be discharged to the capacitor through the third switching means for switching to discharge to the capacitor as The first switching means and the second switching means such that the period during which the first discharging means and the second switching means are in the conducting state is shorter than the period during which the third switching means is in the conducting state. And a control step of alternately performing conduction of the switching means and conduction of the third switching means.

According to such a rectification method, the period during which the first switching means and the second switching means are in the conductive state is shorter than the period during which the third switching means is in the conductive state.
The conduction of the first switching means and the second switching means and the conduction of the third switching means are alternately controlled.

Therefore, according to the rectification method of the present invention, since the polarity of the current flowing from the inductance to the capacitor is switched by the third switching means, both positive and negative voltages with respect to the load are switched. It is possible to supply.

Since the contact between the third switching means and the capacitor always has the lowest potential with respect to the load, the voltage supplied to the load can be set to any value from 0V to the peak value of the rectified voltage.

Further, in the rectification method according to the present invention, the power factor can always be maintained at about 1 because the current waveform through which the inductance flows has a similar shape to the voltage waveform.

Further, in the rectification method according to the present invention, when a diode is used as the third switching means, a signal for controlling the third switching means is unnecessary, which simplifies the device and reduces the manufacturing cost. be able to.

Further, in the rectification method according to the present invention, in the control step, control is performed to change the period during which the first switching means and the second switching means are in the conductive state according to the voltage across the capacitor. The voltage can be kept constant even if the load current changes. Further, there is an advantage that a voltage according to a predetermined target value that changes with time can be supplied regardless of fluctuations in the load current.

The rectification method according to the present invention rectifies the AC voltage from the AC power supply by the rectification means and charges the rectified output to the capacitor via the inductance and the diode connected according to the predetermined polarity, In the rectification method of supplying the terminal voltage of the capacitor to a load, a first switching means for switching conduction and interruption of one rectification output from the rectification means and conduction and interruption of the other rectification output from the rectification step. An energy storage step of storing energy in the inductance by causing a rectified output to flow in the inductance via the second switching means for switching, and a capacitor that stores the energy stored in the energy storage step as a current according to a predetermined voltage polarity. A third switching means for switching to discharge to the And energy release step of releasing into capacitor current through the fourth switching means for switching,
The first switching means and the second switching means are electrically connected so that the period during which the first switching means and the second switching means are in the conducting state is shorter than the period during which the third switching means is in the conducting state. The third switching means and the fourth switching are alternately performed so that the third switching means and the rectifying means and the capacitor are simultaneously conducted. And a control step for controlling the means.

According to such a rectification method, the period during which the first switching means and the second switching means are in the conductive state is shorter than the period during which the third switching means is in the conductive state.
Conduction of the first switching means and the second switching means and conduction of the third switching means are alternately executed, and conduction of the third switching means and conduction between the rectifying means and the capacitor are simultaneously performed. Thus, the third switching means and the fourth switching means are controlled.

Therefore, according to the rectifying method of the present invention, since the polarity of the current flowing from the inductance to the capacitor is switched by the third switching means, both positive and negative voltages with respect to the load are applied. It is possible to supply.

Since the contact point between the third switching means and the capacitor is always at the lowest potential with respect to the load, the voltage supplied to the load can be set to any value from 0V to the peak value of the rectified voltage.

Further, in the rectification method according to the present invention, the power factor can always be maintained at approximately 1 because the current waveform of the inductance has a similar shape to the voltage waveform.

Furthermore, in the rectification method according to the present invention, when a diode is used as the third switching means, a signal for controlling the third switching means is unnecessary, so that the device is simplified and the manufacturing cost is reduced. be able to.

Further, in the rectification method according to the present invention, in the control step, control is performed to change the period during which the first switching means and the second switching means are in the conductive state according to the voltage across the capacitor. The voltage can be kept constant even if the load current changes. Further, there is an advantage that a voltage according to a predetermined target value that changes with time can be supplied regardless of fluctuations in the load current.

Further, according to the rectification method of the present invention, by newly controlling the fourth switching means, it becomes possible to control conduction and interruption between the rectification means responsible for the rectification process and the capacitor. Therefore, the primary side (rectifying means) and the secondary side (capacitor) can be insulated without using a conventional separation transformer, so that the power factor is improved, arbitrary polarity is selected, and the absolute value of the AC waveform peak value is from 0V. In addition to setting the voltage up to, it is possible to prevent electric shock.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating a configuration of a rectifying device shown as a first specific example of the present invention.

FIG. 2 (a) is a waveform diagram showing a voltage waveform over time in the rectifying device shown as the first specific example of the present invention, and FIG. 2 (b) is the first example of the present invention. It is a figure which shows the waveform of the electric current in the rectifier shown as a specific example with respect to time passage.

FIG. 3 is a configuration diagram illustrating a configuration of a modified example of the rectifying device shown as the first specific example of the present invention.

FIG. 4 is a configuration diagram illustrating a configuration of a rectifying device shown as a second specific example of the present invention.

FIG. 5 is a configuration diagram illustrating a configuration of a modified example of the rectifying device shown as the second specific example of the present invention.

FIG. 6 is a configuration diagram illustrating a configuration of a rectifying device shown as a third specific example of the present invention.

FIG. 7A shows operating waveforms of the switch element 13 and the switch element 15 in ON / OFF states when the reference signal 41 is constant in the rectifying device shown as the third specific example of the present invention. FIG. 7 (b) is a waveform diagram showing that the switching element 14 is turned on / off when the reference signal 41 is constant.
It is a wave form diagram which shows the operation waveform of an OFF state.

FIG. 8 is a configuration diagram illustrating a configuration of a rectifying device shown as a fourth specific example of the present invention.

FIG. 9 is a configuration diagram illustrating a configuration of a rectifying device shown as a fifth specific example of the present invention.

FIG. 10 is a configuration diagram illustrating a configuration of a rectifying device shown as a sixth specific example of the present invention.

FIG. 11A shows operating waveforms of the switch elements 13 and 15 in ON / OFF states when the reference signal 41 is constant in the rectifier shown as the third specific example of the present invention. FIG. 11B is a waveform diagram shown in FIG.
Is the switching element 14 when the reference signal 41 is constant.
FIG. 6 is a waveform diagram showing operation waveforms in the ON / OFF state of FIG.

FIG. 12 (a) is a waveform diagram showing a current waveform and a voltage waveform of a conventional capacitor input type half-wave rectifier circuit, and FIG. 12 (b) is a conventional capacitor input type rectifier circuit. It is a wave form diagram which shows a current waveform and a voltage waveform.

FIG. 13 is a waveform diagram showing a voltage waveform in a power supply line that supplies power to a conventional rectifier.

FIG. 14 is a configuration diagram illustrating a configuration of a conventional rectifying device.

FIG. 15 is a configuration diagram illustrating a configuration of a conventional rectifying device.

[Explanation of symbols]

1,1a Rectifier, 2,2a Rectifier, 3 Rectifier, 4 Rectifier, 5 Rectifier, 6 Rectifier, 11
AC power supply, 12 rectifier elements, 13 switch elements, 14
Switch element, 15 switch element, 16 inductance, 17, 17a diode, 18, 18a capacitor, 19 control unit, 20, 20a load, 21
Diode, 22 switch element, 23 switch element, 24 switch element, 31 reference signal generator, 32
Signal comparison part, 33 load voltage detection part, 34 PWM modulation part, 35 switch element control part, 41 reference signal, 42
Potential across capacitor 18, 43 detection load voltage, 44
Comparison signal, 45 PWM modulation signal, 46 control signal,
47 control signals, 48 control signals

Claims (8)

[Claims] 1. An AC voltage from an AC power supply is rectified by a rectifying means, the rectified output is charged into a capacitor through an inductance and a diode connected in accordance with a predetermined polarity, and a terminal voltage of the capacitor is charged. In a rectifying device that supplies a load, connected between the rectifying means and the inductance,
First switching means for switching between conduction and interruption of the rectified output; second switching means having one end connected to the inductance and the diode and the other end connected to the rectifying means; The third switching means connected to the first switching means and the inductance and the other end of which is connected to the capacitor, and the period during which the first switching means and the second switching means are in the conductive state are the third. Control means for alternately executing the conduction of the first switching means and the second switching means and the conduction of the third switching means so that the switching means is shorter than the period in which the switching means is in the conductive state. A rectifying device characterized by the above. 2. The rectifying device according to claim 1, wherein the third switching means is a mechanical switch circuit. 3. The rectifying device according to claim 1, wherein the third switching means is a diode. 4. The control means performs control to change a period during which the first switching means and the second switching means are in a conductive state according to a voltage across the capacitor. 1. The rectifying device according to 1. 5. An AC voltage from an AC power supply is rectified by rectification means, the rectified output is charged into a capacitor through an inductance and a diode connected in accordance with a predetermined polarity, and a terminal voltage of the capacitor is charged. In a rectifying device that supplies a load, connected between the rectifying means and the inductance,
First switching means for switching between conduction and interruption of the rectified output; second switching means having one end connected to the inductance and the diode and the other end connected to the rectifying means; Third switching means connected to the switching means of No. 1 and the inductance and having the other end connected to the capacitor; and fourth switching means for switching between conduction and interruption between the rectification means and the capacitor. The first switching means and the second switching means are arranged such that the period during which the first switching means and the second switching means are in the conductive state is shorter than the period during which the third switching means is in the conductive state. The conduction of the switching means and the conduction of the third switching means are alternately executed, and the conduction of the third switching means and the conduction between the rectifying means and the capacitor are simultaneously performed. Third switching means And a control means for controlling the fourth switching means, the rectifying device. 6. The control unit according to claim 5, wherein the control unit changes the period during which the first switching unit and the second switching unit are in a conductive state according to the voltage across the capacitor. Rectifier. 7. An AC voltage from an AC power supply is rectified by a rectification process, the rectified output is charged into a capacitor through an inductance and a diode connected according to a predetermined polarity, and a terminal voltage of the capacitor is charged. In the rectification method of supplying to a load, a first switching means for switching conduction and interruption of one rectification output from the rectification step, and a second switching means for switching conduction and interruption of the other rectification output from the rectification step. An energy storage step of storing energy in the inductance by causing the rectified output to flow in the inductance via a switching means, and the energy stored in the energy storage step to a capacitor as a current according to a predetermined voltage polarity. Energy for discharging the current to the capacitor through the third switching means for switching to discharge And the first switching means and the second switching means such that the period during which the first switching means and the second switching means are in the conductive state is shorter than the period during which the third switching means is in the conductive state. A rectification method comprising: a control step of alternately performing conduction of the second switching means and conduction of the third switching means. 8. An AC voltage from an AC power supply is rectified by rectification means, the rectified output is charged into a capacitor through an inductance and a diode connected in accordance with a predetermined polarity, and a terminal voltage of the capacitor is charged. In the rectification method of supplying to a load, a first switching means for switching conduction and interruption of one rectification output from the rectification means, and a second switching means for switching conduction and interruption of the other rectification output from the rectification step. An energy storage step of storing energy in the inductance by causing the rectified output to flow in the inductance via a switching means, and the energy stored in the energy storage step to a capacitor as a current according to a predetermined voltage polarity. And a third switching means for switching so as to discharge, and conduction between the rectifying means and the capacitor. An energy discharging step of discharging the current to the capacitor through a fourth switching means for switching between disconnection and a period during which the first switching means and the second switching means are in the conductive state is the third. The conduction of the first switching means and the second switching means and the conduction of the third switching means are alternately executed so as to be shorter than the period in which the switching means is in the conducting state, and the third switching means is conducted. And a control step of controlling the third switching means and the fourth switching means so that the conduction of the switching means and the conduction between the rectifying means and the capacitor are simultaneously performed. And rectification method.