JPH11206130A - Power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power unit which can output DC voltage within a wider range while improving the power factor. SOLUTION: A power unit can vary DC output voltage in a wide range by the combination of four elements being no improvement of power factor with a full wave rectifying circuit, being improvement of power factor with the full wave rectifying circuit, being no improvement of power factor with a voltage doubler rectifying circuit, and being improvement of power factor with the voltage doubler rectifying circuit, controlling a switch 8 for switching of the rectifying circuit by a voltage doubler/full wave rectifying control means 14, thereby switching a first diode bridge 3 to the full wave rectifying circuit or the voltage doubler rectifying circuit, and also, short-circuiting an AC power source 1 through a reactor 2 by the short-circuit element 10 controlled by a power factor improvement control means 13 in each rectifying circuit, thereby controlling the width of the short circuit pulses of the short circuit element while improving the power factor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply using a rectifier circuit having both functions of a full-wave rectification method and a voltage doubler rectification method and capable of generating a wide range of output voltage while improving the power supply power factor. Related to the device.

[0002]

2. Description of the Related Art As an apparatus having a full-wave rectifier circuit and a voltage doubler rectifier circuit as a rectifier circuit, for example, Japanese Patent Application Laid-Open No.
There is an inverter device described in No. 57. Thus, in a device having a full-wave rectifier circuit and a voltage doubler rectifier circuit,
When the power supplied to the load is large, the supply current is reduced by increasing the DC output voltage using a voltage doubler rectifier circuit, and the loss (copper loss) caused by the flow of a large current is reduced. On the other hand, when the power supplied to the load is small, a full-wave rectifier circuit is used to lower the DC output voltage, thereby improving efficiency, reducing leakage current,
The noise is reduced.

[0003]

As described above, a power supply device using a full-wave rectifier circuit and a voltage doubler rectifier circuit is effective for improving the efficiency, but it is difficult to extract a large amount of active power from the power supply device. However, there is a problem that the power supply power factor needs to be improved, and the above-described conventional device cannot improve the power supply power factor.

[0004] The present invention has been made in view of the above,
An object of the present invention is to provide a power supply device capable of outputting a wider range of DC voltage while improving the power supply power factor.

[0005]

To achieve the above object, according to the present invention, a rectifier circuit for rectifying an AC voltage from an AC power supply to generate a DC voltage, and a rectifier circuit connected in series to the AC power supply. It has a connected reactor, short-circuit control means for controlling to short-circuit the AC power supply via the reactor, and switching control means for controlling to switch the rectifier circuit to a full-wave rectifier circuit or a voltage doubler rectifier circuit. That is the gist.

According to the first aspect of the present invention, the rectifier circuit is switched to a full-wave rectifier circuit or a voltage doubler rectifier circuit by the switching control means, and in each rectifier circuit, the AC power is supplied via the reactor by the short-circuit control means. Since the short-circuit pulse width can be controlled while improving the power factor by short-circuiting, there is no power factor improvement with full-wave rectifier circuit, there is power factor improvement with full-wave rectifier circuit, and there is no power factor improvement with voltage doubler rectifier circuit The DC output voltage can be varied in a wide range by the combination of the voltage doubler rectifier circuit and the power factor improvement.

The present invention according to claim 2 is based on claim 1.
In the invention described in the above, the switching control means controls the rectification circuit to a full-wave rectification circuit or a voltage doubler rectification circuit based on an output signal of the short-circuit control means and an input current to a power supply or an output current from the power supply. The point is to perform switching control.

According to the present invention, switching control to a full-wave rectifier circuit or a voltage doubler rectifier circuit is performed based on the output signal of the short-circuit control means and the input current or output current of the power supply device. An accurate output voltage corresponding to a load can be supplied over a wide range.

Further, the present invention according to claim 3 provides the invention according to claim 1.
In the invention described above, when an inverter circuit that performs pulse width modulation control of a DC voltage from the rectifier circuit as a load of a power supply device is connected to the switching control unit, an output signal of the short-circuit control unit or a signal from the inverter circuit. The gist is to perform switching control of the rectifier circuit to a full-wave rectifier circuit or a voltage doubler rectifier circuit based on a duty ratio of a pulse width modulation control signal.

According to the present invention, when an inverter circuit for performing pulse width modulation control is connected as a load, the output signal of the short-circuit control means or the duty ratio of the pulse width modulation control signal from the inverter circuit. , The switching control to the full-wave rectifier circuit or the voltage doubler rectifier circuit is performed, so that an accurate output voltage according to the load of the inverter circuit can be supplied over a wide range.

According to a fourth aspect of the present invention, in the third aspect of the invention, when the short-circuit control means switches the rectifier circuit to a full-wave rectifier circuit,
When the duty ratio of the pulse width modulation control signal of the inverter circuit becomes close to 100%, a short-circuit pulse width for short-circuiting the AC power supply via the reactor is controlled, and the switching control means sets the short-circuit pulse width to a predetermined value. When the above occurs, the rectifier circuit is controlled to be switched to a voltage doubler rectifier circuit, and the short-circuit control means controls the short-circuit when the duty ratio of the pulse width modulation control signal of the inverter circuit becomes close to 100%. The gist is to control the pulse width.

According to the present invention, when the rectifier circuit is switched to a full-wave rectifier circuit, the short-circuit pulse width is controlled when the duty ratio of the pulse width modulation control signal becomes close to 100%. When the short-circuit pulse width becomes a predetermined value or more, the switching to the voltage doubler rectifier circuit is performed. When the duty ratio of the pulse width modulation control signal becomes close to 100%, the rectifier circuit is switched to control the short-circuit pulse width. It can be done smoothly.

Further, the present invention described in claim 5 is based on claim 1.
In the invention described in the above, when the short-circuit control means controls the switching control means to switch the rectifier circuit from a full-wave rectifier circuit to a voltage doubler rectifier circuit, the output voltage of the power supply device is set near a maximum value or a voltage doubler in advance. The gist of the present invention is to control a short-circuit pulse width for short-circuiting an AC power supply via the reactor so that an output voltage value obtained when switching to a rectifier circuit is obtained.

According to the fifth aspect of the present invention, when the rectifier circuit is controlled so as to switch from the full-wave rectifier circuit to the voltage doubler rectifier circuit, the output voltage of the power supply device is preliminarily near the maximum value or the voltage doubler rectifier circuit. Since the short-circuit pulse width is controlled so as to be an output voltage value obtained when the switching is performed, the fluctuation of the power supply voltage when the switching is performed from the full-wave rectification to the double voltage rectification can be suppressed.

Further, the present invention described in claim 6 is the first invention.
In the invention described in the above, when the short-circuit control means controls the switching control means to switch the rectifier circuit from a voltage doubler rectifier circuit to a full-wave rectifier circuit, a short-circuit pulse width for short-circuiting an AC power supply via the reactor. Is controlled in advance to be zero, and after the switching control means switches the rectifier circuit to a full-wave rectifier circuit, the short-circuit pulse width is changed so that the output voltage of the power supply device becomes the output voltage of the power supply device before switching. Is to be controlled.

According to the present invention, when the rectifier circuit is controlled to switch from the voltage doubler rectifier circuit to the full-wave rectifier circuit, the full-wave rectifier circuit is controlled in advance so that the short-circuit pulse width becomes zero. After switching to the rectifier circuit, control the short-circuit pulse width so that the output voltage of the power supply becomes the output voltage of the power supply before switching. It becomes possible to suppress.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing a configuration of a power supply device according to a first embodiment of the present invention. The power supply device shown in FIG. 1 includes a reactor 2 having one end connected to one output end of an AC power supply 1, and the other end of the reactor 2 is connected to a first diode bridge 3 including four diodes and a smoothing diode. It is composed of electrolytic capacitors 4, 5, and 6, and is connected to a converter constituting a rectifier circuit for rectifying an AC voltage from the AC power supply 1 into a DC voltage. The DC voltage from the converter is supplied to a load 7.

A rectifying circuit switching switch 8 is connected between one of the input terminals of the first diode bridge 3 and a connection point of the smoothing capacitors 4 and 5, and the rectifying circuit switching switch 8 is turned off. , The first diode bridge 3 forms a full-wave rectifier circuit, and when the rectifier circuit switch 8 is on, the first diode bridge 3
Constitutes a voltage doubler rectifier circuit. In addition,
The rectifier circuit switching switch 8 includes a relay, a triac, or a diode bridge and a one-way short-circuit element such as an IGBT, a bipolar transistor, or a MOSFET.

A second diode bridge 9 is connected to both ends of the AC power supply 1 via the reactor 2, and both output terminals of the second diode bridge 9 are composed of, for example, a bipolar transistor, an IGT, a MOSFET and the like. When the short-circuiting element 10 which is a switching element is connected and the short-circuiting element 10 is turned on, the reactor 2 and the second
The AC power supply 1 via the diode bridge 9 of
Thereby, the power factor of the power supply device can be improved.

The control terminal of the short-circuit element 10, that is, the base, is connected to a power factor improvement control means 13 provided in the controller 11, and the short-circuit element 10 is driven by the power factor improvement control means 13. 10 is turned on.

Further, zero-cross detecting means 12 provided in the controller 11 is connected to both ends of the AC power supply 1, so that the zero-cross detecting means 12 detects the time when the AC voltage of the AC power supply 1 passes through the zero cross point. The detection signal is supplied to the power factor improvement control means 13.

Further, the controller 11 has, in addition to the zero-crossing detecting means 12 and the power factor improvement controlling means 13, a voltage doubler / full wave rectifying controlling means 14 constituting a switching control means. The control means 14 controls the rectifier circuit switching switch 8 based on the width of the short-circuit pulse, which is an output signal of the power factor improvement control means 13 constituting the short-circuit control means, and the input current or output current of the power supply device. Control is performed so that the rectifier circuit constituted by one diode bridge 3 is switched to a full-wave rectifier circuit or a voltage doubler rectifier circuit.

In the power supply device of the present embodiment configured as described above, when a sine wave AC voltage is input from the AC power supply 1, the zero-cross point of the AC voltage is detected by the zero-cross detecting means 12 of the controller 11. Are supplied to the power factor improvement control means 13. The power factor improvement control means 13 calculates a short-circuit start time and a short-circuit time from a zero-cross point of the short-circuit signal, and outputs the calculated short-circuit signal to the zero-cross detection means 1
The output is delayed from the zero-cross point detected in step 2 by the short-circuit start time to drive the short-circuit element 10 to the ON state, thereby short-circuiting the AC power supply 1 via the second diode bridge 9 and the reactor 2. When the AC power supply 1 is short-circuited during the short-circuit signal and the short-circuit element 10 is opened to an off state, the energy stored in the reactor 2 is released to the load side, and the first diode bridge 3 and the capacitors 4, 5, 6
And supplied to the load 7.

By short-circuiting the AC power supply 1 via the reactor 2 as described above, the conduction time of the power supply current is extended,
The power supply power factor will be improved.

The power supply device of the present embodiment configured as described above has the short-circuit element 1 controlled by the power factor improvement control means 13.
By short-circuiting the AC power supply 1 via the reactor 2 by 0 and improving the power factor by widening the conduction angle of the power supply current, and by varying the short-circuit time of the short-circuit element 10 under the control of the power factor improvement control means 13. The first diode bridge 3 is switched to a full-wave rectifier circuit or a voltage-doubler rectifier circuit by the rectifier circuit switching switch 8 under the control of the booster function for varying the DC output voltage of the power supply device and the control of the voltage-doubler / full-wave rectifier control means 14. And a function of varying the DC output voltage of the power supply device.

Next, the operation of the power supply device configured as described above will be described with reference to FIG. FIG. 2 is a diagram showing a power factor and an output voltage of the power supply device with respect to an input current of the power supply device.

As shown in FIG. 2, when the input current is small, the voltage doubler / full-wave rectification control means 14 controls the rectification circuit switching switch 8 to be turned off, and the rectification circuit by the first diode bridge 3. Is set in the full-wave rectifier circuit, and the power factor improvement control means 13 controls the short-circuit element 10 not to be short-circuited, and thus to not improve the power factor, thereby reducing the DC output voltage of the power supply device. Controlling.

When the rectifier circuit of the first diode bridge 3 is similarly set to a full-wave rectifier circuit and the input current is slightly large, the short-circuit element 10 is intermittently controlled by the power factor improvement control means 13. That is, the short-circuit pulse width to be supplied to the short-circuit element
The DC output voltage of the power supply device is controlled to be slightly larger by improving the power factor and increasing the DC output voltage.

Further, when the input current is large and the boost ratio by the power factor improvement control means 13 exceeds a predetermined value,
The voltage doubler / full-wave rectification control means 14 controls the rectifier circuit switching switch 8 to turn on, and switches the rectifier circuit by the first diode bridge 3 to a voltage doubler rectifier circuit.
The DC output voltage of the power supply device is controlled to be large by controlling the short-circuit element 10 not to be short-circuited by the power factor improvement control means 13 and therefore not to improve the power factor.

In a state where the rectifier circuit of the first diode bridge 3 is similarly set as a voltage doubler rectifier circuit, when the input current is larger and a larger output voltage is required, the rectifier circuit is supplied to the short-circuit element 10. The power factor improvement control means 13 variably controls the short-circuit pulse width to improve the power factor and increase the DC output voltage, thereby further controlling the DC output voltage of the power supply device.

That is, in the present embodiment, the rectifier circuit by the first diode bridge 3 is turned on / off by the rectifier circuit switching switch 8 under the control of the voltage doubler / full wave rectifier control means 14 so that the full-wave rectifier circuit or the voltage doubler. Controlled by a rectifier circuit, the DC output voltage of the power supply is divided into two main stages,
Each of the two areas is further divided into power factor improvement control means 13.
The power factor is not improved and the power factor is improved by the short-circuit variable control of the short-circuit element 10 by the above.
A DC output voltage region having a plurality of stages is formed, whereby the power factor improvement control means 13 and the voltage doubler / full-wave rectification control means 14 control the first DC output voltage from the smallest DC output voltage to the second DC output voltage. 4 can be freely output.

FIG. 3 shows a state in which the power factor improvement control means 13 and the voltage doubler / full-wave rectification control means 14 control the power-factor improvement control from the state without the power factor improvement by the full-wave rectification to increase the output voltage. FIG. 4 is a diagram showing a power factor / output voltage with respect to an input voltage when switching to voltage doubler rectification while performing the power factor improvement control. Even with such control, an output voltage can be generated in a wide range from a small voltage to a large voltage as in the case of FIG.

FIG. 4 is a circuit diagram showing a configuration of a power supply device according to another embodiment of the present invention. In the power supply device shown in FIG. 1, an inverter circuit 15 for performing pulse width modulation (PWM) control and a motor 16 are connected as the load 7 in the power supply device shown in FIG. 1, and an inverter control circuit 17 for controlling the inverter circuit 15 is provided. Is provided in the controller 11, and the other configuration and operation are the same as those in FIG.

The power supply device shown in FIG. 4 has a function of improving the power factor by increasing the conduction angle of the power supply current by short-circuiting the AC power supply 1 via the reactor 2 by the short-circuiting element 10.
And a voltage boosting function for varying the DC output voltage by varying the short-circuit time of the first DC / DC converter. And the function of changing Further, the inverter control circuit 17 varies the duty ratio of the drive signal to the inverter circuit 15 to variably control the output voltage of the inverter circuit 15 and drives the electric motor 16.

FIG. 5 is a diagram showing PWM duty ratio / power factor / output voltage with respect to input current in the power supply device shown in FIG. As shown in FIG. 5, the DC output voltage is changed in two stages by switching between a full-wave rectifier circuit and a doubler rectifier circuit by the voltage-doubler / full-wave rectifier controller 14, and the boosting by the power factor improvement controller 13 is performed. By combining the method of varying the DC output voltage with the function, the DC output voltage can be varied over a wide range. That is, similarly to the embodiment of FIG. 1, four combinations of full-wave rectification and no power factor improvement, full-wave rectification and power factor improvement, double voltage rectification and no power factor improvement, double voltage rectification and power factor improvement Thus, the DC output voltage can be varied in a wide range.

In FIG. 5, when the input current is small,
Full-wave rectification and duty ratio of PWM control signal is almost 1
At the time when the power supply reaches 00%, the power factor improvement control is performed, the short-circuit pulse width is increased, and the DC output voltage of the power supply device is increased. Then, when the input current increases and the boost ratio exceeds a certain value, the mode is switched to voltage doubler rectification. At this time, since the DC output voltage increases, the duty ratio of the PWM control signal becomes 100% or less. As the current increases, the duty ratio of the PWM signal becomes almost 100% again.
At this point, the power factor improvement control is performed to extend the short-circuit pulse.

FIG. 6 is a diagram showing a PWM duty ratio / power factor / output voltage with respect to an input current showing another operation in the embodiment shown in FIG. In the operation example shown in FIG. 6, regardless of the full-wave rectification or the voltage doubler rectification circuit, even when the duty ratio of the PWM control signal has not reached 100%, the power factor improvement control is performed and the power supply voltage is reduced. By increasing the torque, it is possible to increase the torque and the number of revolutions of the electric motor as a load.

FIG. 7 is a diagram showing the operation of the power supply device according to the third embodiment of the present invention, and shows the PWM duty ratio / power factor / output voltage with respect to the input current. In the present embodiment, as shown in FIG. 7, in the full-wave rectification, when switching to the voltage doubler rectification, the power factor improvement controller 13 raises the power supply voltage to the power supply voltage obtained when the voltage value is previously switched to the voltage doubler rectification. By doing so, it is possible to suppress fluctuations in the power supply voltage when switching from full-wave rectification to double voltage rectification.

It should be noted that even if the power factor improvement control means 13 cannot increase the power supply voltage value obtained when the voltage value is switched to the double voltage rectification, the power factor improvement control means 1
By increasing the power supply voltage to the maximum value raised by 3, the fluctuation of the power supply voltage can be minimized.

FIG. 8 is a diagram showing the operation of the power supply device according to the fourth embodiment of the present invention, and shows the PWM duty ratio / power factor / output voltage with respect to the input current. In the present embodiment, as shown in FIG. 8, when switching to full-wave rectification in the voltage doubler rectification, the power factor improvement control by the power factor improvement control means 13 is not performed in advance, and the power supply voltage is reduced and the full-wave rectification is performed. After switching to the rectifier circuit, perform power factor improvement control, raise the power supply voltage to the voltage value before switching,
It is possible to suppress the fluctuation of the power supply voltage when switching from the voltage doubler rectification to the full wave rectification.

As in the third embodiment, when switching from the voltage doubler rectification to the full-wave rectification, even if the power supply voltage cannot be increased to the voltage value before the switching by the power factor improvement controller 13, By increasing the power supply voltage to the maximum value raised by the power factor improvement control means 13, the fluctuation of the power supply voltage can be suppressed to the minimum value.

Further, when an inverter circuit of an air conditioner is connected as the load 7 of each power supply device described above, the voltage doubler is applied so that the operation of the air conditioner is in full-wave rectification in the cooling mode or the dehumidifying mode. By controlling the rectifying circuit changeover switch 8 by the full-wave rectification control means 14, efficient control can be achieved.

The first diode bridge 3, the second diode bridge 9, the short-circuit element 10, and the rectifying circuit switching switch 8 in each of the above embodiments are housed in one package, so that the number of parts can be reduced. The number of terminals can be reduced, the reliability can be improved, the size can be reduced, the economy can be increased, and the mounting can be facilitated.

[0045]

As described above, according to the first aspect of the present invention, the rectifier circuit is switched to the full-wave rectifier circuit or the voltage doubler rectifier circuit by the switch control means, and the short-circuit control means is used in each rectifier circuit. The short-circuit pulse width can be controlled while improving the power factor by short-circuiting the AC power supply via the reactor, so there is no power factor improvement with full-wave rectifier circuit, there is power factor improvement with full-wave rectifier circuit, and double voltage The DC output voltage can be varied in a wide range by the combination of the rectifier circuit and no power factor improvement, and the voltage doubler rectifier circuit and the power factor improvement can be adjusted in a wide range. Optimal control according to the DC output voltage required by the load In this way, efficiency and economy can be improved.

According to the present invention, the switching control to the full-wave rectifier circuit or the voltage doubler rectifier circuit is performed based on the output signal of the short-circuit control means and the input current or output current of the power supply device. Thus, it is possible to efficiently supply an accurate output voltage according to the load over a wide range.

Furthermore, according to the present invention, when an inverter circuit for performing pulse width modulation control is connected as a load, the output signal of the short-circuit control means or the duty of the pulse width modulation control signal from the inverter circuit is output. Since the switching control to the full-wave rectifier circuit or the voltage doubler rectifier circuit is performed based on the ratio, an accurate output voltage according to the load of the inverter circuit can be efficiently supplied over a wide range.

According to the present invention, when the rectifier circuit is switched to the full-wave rectifier circuit, the short-circuit pulse width is controlled when the duty ratio of the pulse width modulation control signal is close to 100%. When the short-circuit pulse width exceeds a predetermined value, it switches to the voltage doubler rectifier circuit, and when the duty ratio of the pulse width modulation control signal becomes close to 100%, the short-circuit pulse width is controlled. Can be done.

According to the fifth aspect of the present invention, when the rectifier circuit is controlled so as to switch from the full-wave rectifier circuit to the voltage doubler rectifier circuit, the output voltage of the power supply device is set near the maximum value or the voltage doubler rectifier in advance. Since the short-circuit pulse width is controlled so that the output voltage value is obtained when switching to the circuit,
It is possible to suppress fluctuations in the power supply voltage when switching from full-wave rectification to voltage doubler rectification.

Further, according to the present invention, when the rectifier circuit is controlled to switch from the voltage doubler rectifier circuit to the full-wave rectifier circuit, the short-circuit pulse width is controlled in advance to be zero, After switching to the wave rectifier circuit, the short-circuit pulse width is controlled so that the output voltage of the power supply becomes the output voltage of the power supply before switching, so the power supply voltage changes when switching from double voltage rectification to full-wave rectification Can be suppressed.

[Brief description of the drawings]

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

2 is a diagram showing a power factor and an output voltage of the power supply device with respect to an input current of the power supply device shown in FIG.

FIG. 3 shows a state in which power factor improvement control is performed from a state without power factor improvement in the full-wave rectification of the power supply device shown in FIG. 1, and an output voltage is increased. It is a figure which shows the power factor / output voltage with respect to the input voltage at the time of switching.

FIG. 4 is a circuit diagram showing a configuration of a power supply device according to another embodiment of the present invention.

5 is a diagram showing a PWM duty ratio / power factor / output voltage with respect to an input current in the power supply device shown in FIG.

6 is a diagram showing a PWM duty ratio / power factor / output voltage with respect to an input current showing another operation in the embodiment shown in FIG. 4;

FIG. 7 is a diagram showing an operation of the power supply device according to the third embodiment of the present invention, and shows a PWM duty ratio / power factor / output voltage with respect to an input current.

FIG. 8 is a diagram showing an operation of the power supply device according to the fourth embodiment of the present invention, and shows a PWM duty ratio / power factor / output voltage with respect to an input current.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 AC power supply 2 Reactor 3 First diode bridge 4, 5, 6 Smoothing capacitor 7 Load 8 Rectifier circuit switch 9 Second diode bridge 10 Short circuit element 11 Controller 12 Zero cross detection means 13 Power factor improvement control means 14 Double voltage / Full-wave rectification control means 15 Inverter circuit 17 Inverter control circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02P 7/63 302 H02P 7/63 302C

Claims (6)

[Claims] 1. A rectifier circuit for rectifying an AC voltage from an AC power supply to generate a DC voltage, a reactor connected in series to the AC power supply, and controlling the AC power supply to be short-circuited via the reactor. A power supply device comprising: a short-circuit control unit; and a switch control unit that controls the rectifier circuit to switch to a full-wave rectifier circuit or a voltage doubler rectifier circuit. 2. The switching control means according to claim 1, further comprising: The power supply device according to claim 1, wherein switching control is performed. 3. The switching control means, when an inverter circuit for performing pulse width modulation control of a DC voltage from the rectifier circuit as a load of a power supply device is connected, an output signal of the short-circuit control means or a signal from the inverter circuit. The power supply device according to claim 1, wherein switching control of the rectifier circuit to a full-wave rectifier circuit or a voltage doubler rectifier circuit is performed based on a duty ratio of a pulse width modulation control signal. 4. The short-circuit control means, wherein the switching control means switches the rectifier circuit to a full-wave rectifier circuit.
When the duty ratio of the pulse width modulation control signal of the inverter circuit is close to 100%, a short-circuit pulse width for short-circuiting the AC power supply via the reactor is controlled, and the switching control means sets the short-circuit pulse width to a predetermined value. When the above occurs, the rectifier circuit is controlled to be switched to a voltage doubler rectifier circuit, and the short-circuit control means controls the short-circuit when the duty ratio of the pulse width modulation control signal of the inverter circuit becomes close to 100%. 4. The power supply according to claim 3, wherein the pulse width is controlled. 5. When the switching control means controls the switching control means to switch the rectifier circuit from a full-wave rectifier circuit to a voltage-doubler rectifier circuit, the output voltage of the power supply device is preliminarily near the maximum value or a voltage doubler. 2. The power supply device according to claim 1, wherein a short-circuit pulse width for short-circuiting an AC power supply via the reactor is controlled so as to obtain an output voltage value obtained when switching to a rectifier circuit. 6. The short-circuit pulse width for short-circuiting an AC power supply via the reactor when the switching control means controls the rectifier circuit to switch from the voltage doubler rectifier circuit to a full-wave rectifier circuit. Is controlled in advance to be zero, and after the switching control means switches the rectifier circuit to a full-wave rectifier circuit, the short-circuit pulse width is changed so that the output voltage of the power supply device becomes the output voltage of the power supply device before switching. The power supply device according to claim 1, wherein the power supply device is controlled.