JP2016086585A - Power unit, and air conditioner employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-efficiency power unit which includes a power factor improvement function and reduces a voltage drop by suppressing an excessive in-rush current that may be generated in powering-on, and suppressing a reverse recovery current of a reverse blocking diode.SOLUTION: The power unit comprises: a rectification circuit in which first to fourth diodes are configured in a diode bridge; a first series circuit that is configured by connecting a fifth diode and a first switching element; a second series circuit which is configured by connecting a sixth diode and a second switching element; a smoothing capacitor that is connected between positive electrode side wiring and negative electrode side wiring; a first reactor which is connected between a first output terminal of an AC power source and a first AC input terminal of the rectification circuit; a second reactor which is connected between a second output terminal of the AC power source and a second AC input terminal of the rectification circuit; a first coil which is connected between the first switching element and the first AC input terminal of the rectification circuit; and a second coil which is connected between the second switching element and the second AC input terminal of the rectification circuit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device and an air conditioner using the same.

A power supply device that receives an AC power supply and generates a DC voltage basically has a function of rectifying and smoothing an AC voltage (power) into a DC voltage (power).
However, a function for improving the power factor, a function for dealing with an excessive inrush current generated when the power supply device is turned on, and a function for reducing the reverse recovery current of the diode are required.
As a basic circuit for rectifying and smoothing an AC voltage (power) into a DC voltage (power), there is a so-called capacitor input rectifying and smoothing circuit (see FIG. 5, details will be described later) including a diode bridge and a smoothing capacitor.
As a technique for improving the power factor on the AC input side during rectification, a part of the rectifier diode is replaced with a switching element, a reactor is provided between the switching element and the AC power supply, and the power factor is increased by a boost chopper. There is a rectifying / smoothing circuit for improvement (see FIG. 6, details will be described later).
Further, as a technique for preventing an excessive inrush current generated at power-on from flowing into the switching element and destroying the element, a rectifying / smoothing circuit provided with a rectifier diode that bypasses the inrush current (see FIG. 9, Patent Document 1). Details will be described later).
Further, there is a rectifying / smoothing circuit (see FIG. 10, details will be described later) for improving the power factor by providing a reactor, a switching element, and a reverse blocking diode between the rectifying diode and the smoothing capacitor in the capacitor input rectifying / smoothing circuit.
As a technique for reducing the reverse recovery current of the reverse blocking diode, a rectifying / smoothing circuit in which a coil and a diode are provided between the switching element and the reverse blocking diode (see FIG. 11, Patent Document 2, details will be described later). )

JP 2004-72846 A JP-A-7-284268

However, the capacitor input rectifying / smoothing circuit including the diode bridge and the smoothing capacitor shown in FIG. 5 has a problem that the power factor during rectification is low (details will be described later).
6 is replaced with a switching element, a reactor is provided between the switching element and the AC power supply, and the power factor correction is performed by the boost chopper, the rectifying / smoothing circuit is configured when the power supply device is turned on. There is a problem that the switching element may be destroyed by an excessive inrush current that is generated (details will be described later).
Further, a reactor is provided between the switching element shown in FIG. 9 (similar to Patent Document 1) and an AC power supply, and a rectifying diode that further bypasses the inrush current is provided in a rectifying and smoothing circuit that improves the power factor by a boost chopper. In the rectifying and smoothing circuit, when the switching element is operated when the input power is small, there is a problem that the obtained effect is smaller than the energy required for switching and the energy efficiency is poor.
In the rectifying / smoothing circuit in which the reactor, the switching element, and the reverse blocking diode are provided between the rectifying diode and the smoothing capacitor in the capacitor input rectifying / smoothing circuit shown in FIG. 10 to improve the power factor, the reverse blocking diode is instantaneous. However, there is a problem that reverse recovery current (FIG. 12) flows and voltage loss and power loss occur (details will be described later).
In the rectifying and smoothing circuit for reducing the reverse recovery current of the reverse blocking diode by providing a coil and a diode between the switching element and the reverse blocking diode shown in FIG. There is a problem that the switching element may be destroyed by the inrush current (details will be described later).

Therefore, the present invention solves such a problem, and the object of the present invention is to have a power factor correction function, suppress an excessive inrush current generated when the power is turned on, and reverse recovery current of the reverse blocking diode. Is to provide a power supply device that is small in size, small in size, and highly efficient.
Another object of the present invention is to mount the power supply device on an air conditioner to improve the efficiency and size of the air conditioner.

In order to solve the above-described problems and achieve the object of the present invention, the present invention is configured as follows.
That is, the power supply device of the present invention includes a first, second, third, and fourth diode to form a diode bridge, and a connection point between the anode of the first diode and the cathode of the second diode is a first alternating current. As an input terminal, a connection point between the anode of the third diode and the cathode of the fourth diode is used as a second AC input terminal, and a connection point between the cathode of the first diode and the cathode of the third diode is connected to the positive electrode side wiring. And connecting a rectifier circuit in which a connection point between the anode of the second diode and the anode of the fourth diode is connected to the negative-side wiring, the anode of the fifth diode, and the second terminal of the first switching element, A first series circuit in which a cathode of a fifth diode is connected to the positive side wiring and a first terminal of the first switching element is connected to the negative side wiring; An anode of the anode and a second terminal of the second switching element are connected, a cathode of the sixth diode is connected to the positive side wiring, and a first terminal of the second switching element is connected to the negative side wiring. Two series circuits, a smoothing capacitor connected between the positive electrode side wiring and the negative electrode side wiring, and a first capacitor connected between the first output terminal of the AC power source and the first AC input terminal of the rectifier circuit. A first reactor, a second reactor connected between a second output terminal of the AC power source and a second AC input terminal of the rectifier circuit, a second terminal of the first switching element, and a first AC of the rectifier circuit A first coil connected between the input terminal and a second coil connected between the second terminal of the second switching element and the second AC input terminal of the rectifier circuit. And
Other means will be described in the embodiment for carrying out the invention.

According to the present invention, a power factor correction function is provided, an excessive inrush current generated at the time of power-on is suppressed, a reverse recovery current of a reverse blocking diode is suppressed, a voltage drop is small, a small size, and a highly efficient power source Equipment can be provided.
Moreover, the said power supply device can be mounted in an air conditioner and the efficiency and size reduction of an air conditioner can be achieved.

It is a figure which shows the circuit structure of the power supply device which is 1st Embodiment of this invention. It is a figure which shows the connection structure of the circuit structure of the power supply device which is 2nd Embodiment of this invention, and the electric compressor provided with the power supply device and motor which are mounted in the air conditioner which is 5th Embodiment. It is a figure which shows the circuit structure of the power supply device which is 3rd Embodiment of this invention. It is a figure which shows the connection structure of the circuit structure of the power supply device which is 4th Embodiment of this invention, and the electric compressor provided with the power supply device and motor which are mounted in the air conditioner which is 6th Embodiment. It is a figure which shows the circuit structure of the 1st example of the capacitor | condenser input rectification smoothing circuit which receives an alternating current power supply as a comparative example, and produces | generates a DC voltage. It is a figure which shows the circuit structure of the 2nd example of the capacitor | condenser input rectification smoothing circuit which receives an alternating current power supply as a comparative example, and produces | generates a DC voltage. It is a figure which shows the voltage waveform and electric current waveform of the input side of the capacitor | condenser input rectification smoothing circuit shown in FIG. 5 as a comparative example. It is a figure which shows the voltage waveform and electric current waveform of the input side of the capacitor | condenser input rectification smoothing circuit shown in FIG. 6 as a comparative example. It is a figure which shows the circuit structure of the 3rd example of the capacitor | condenser input rectification smoothing circuit which receives an alternating current power supply as a comparative example, and produces | generates a DC voltage. It is a figure which shows the circuit structure of the 4th example of the capacitor | condenser input rectification smoothing circuit which receives an alternating current power supply and produces | generates a DC voltage as a comparative example. It is a figure which shows the circuit structure of the 5th example of the capacitor | condenser input rectification smoothing circuit which receives an alternating current power supply and produces | generates a DC voltage as a comparative example. FIG. 11 is a diagram showing that a reverse recovery current flows in the circuit of FIG. 10 as a comparative example. It is a figure which shows that the reverse recovery current stopped flowing in the circuit of FIG. 11 as a comparative example.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the drawings.

(First Embodiment / Power Supply Device)
The power supply device which is 1st Embodiment of this invention is demonstrated with reference to FIG.

FIG. 1 is a diagram showing a circuit configuration of a power supply device 10 according to the first embodiment of the present invention.
In FIG. 1, a power supply device 10 includes reactors (reactors) 14a and 14b, rectifier diodes (diodes) 11a, 11b, 11c and 11d, coils 15a and 15b, reverse blocking diodes (diodes) 12a and 12b, and switching elements (MOSFETs). 13 a and 13 b and a smoothing capacitor (capacitor) 16.
In claim 1 of the claims, the reactors 14a and 14b correspond to a first reactor and a second reactor, respectively. The rectifier diodes 11a, 11b, 11c, and 11d correspond to first, second, third, and fourth diodes, respectively, in order. The coils 15a and 15b correspond to a first coil and a second coil, respectively. The reverse blocking diodes 12a and 12b correspond to fifth and sixth diodes, respectively. The switching elements 13a and 13b correspond to a first switching element and a second switching element, respectively.

《Rectifier circuit configuration with rectifier diode》
The rectifier diodes 11a, 11b, 11c, and 11d form a diode bridge and have a function of a rectifier circuit.
That is, the anode of the rectifier diode 11 a is connected to the cathode of the rectifier diode 11 b, the cathode of the rectifier diode 11 a is connected to the direct current positive electrode side wiring 101, and the anode of the rectifier diode 11 b is connected to the direct current negative electrode side wiring 102. Has been.

The anode of the rectifier diode 11c is connected to the cathode of the rectifier diode 11d, the cathode of the rectifier diode 11c is connected to the DC positive-side wiring 101, and the anode of the rectifier diode 11d is connected to the DC negative-side wiring 102. Yes.
A connection point between the rectifier diode 11a and the rectifier diode 11b is a first AC input terminal of the rectifier circuit, and a connection point between the rectifier diode 11c and the rectifier diode 11d is a second AC input terminal of the rectifier circuit.
That is, the first and second output terminals of the AC power supply 201 are connected to the first and second AC input terminals of the rectifier circuit (rectifier diodes 11a, 11b, 11c, and 11d) via the reactors 14a and 14b, respectively. . Then, the voltage is rectified by the rectifier circuits (rectifier diodes 11a, 11b, 11c, and 11d), and a voltage (power) mainly including the rectified DC component is supplied to the positive electrode side wiring 101 and the negative electrode side wiring 102.

Further, the voltage (power) mainly composed of the rectified direct current component in the positive electrode side wiring 101 and the negative electrode side wiring 102 is smoothed and converted into a DC voltage by the action of the smoothing capacitor 16 and supplied to the load 202. .
The configuration and operation of the rectifier circuit (rectifier diodes 11a, 11b, 11c, 11d) and the smoothing capacitor 16 are referred to as a capacitor input rectification smoothing circuit.
Further, only this rectifier circuit (rectifier diodes 11a, 11b, 11c, 11d) naturally has a rectifying action.
However, if it is assumed that only this rectifier circuit is provided, the voltage (characteristic line 1001) applied between the first AC input terminal and the second AC input terminal is as shown in FIG. In a small region, there is a section where current (characteristic line 1002) does not flow.
This is because the rectifier diodes (11a, 11b, 11c, 11d) have a built-in potential at the PN junction (difference in work function between the P-type semiconductor and the N-type semiconductor at the PN junction), so that the voltage is small in the forward direction (generally). This is because an electric current does not flow. If there is a section in which this current does not flow, the difference between the current waveform and the sine waveform becomes large, which causes the power factor to decrease.

However, in FIG. 1, the reactors 14a and 14b are respectively connected to the first and second output terminals of the AC power supply 201 and the first AC input terminal and the second AC input of the rectifier circuit (rectifier diodes 11a, 11b, 11c and 11d). It is provided between the terminals.
The reactors 14a and 14b have an action of accumulating and releasing electric energy. Further, there is a property that a counter electromotive force is generated when a current flows. By the action of the reactors 14a and 14b, a steep change in current is suppressed, and even when the input voltage is reduced, the stored energy is released, so that the current slope and the maximum value are reduced, and rectification is performed. The current waveform flowing in the circuit is close to a sine wave, and the power factor is improved.
The power factor improvement effect of the rectifier circuits (rectifier diodes 11a, 11b, 11c, and 11d) by the reactors 14a and 14b is effective even when the switching elements 13a and 13b described later are not switched.

<Configuration of boost chopper circuit>
Further, a step-up chopper circuit is configured by reverse blocking diodes 12a and 12b, switching elements 13a and 13b, reactors 14a and 14b, and coils 15a and 15b.
That is, the anode of the reverse blocking diode 12a and the second terminal of the switching element 13a are connected, the cathode of the reverse blocking diode 12a is connected to the positive electrode side wiring 101, and the first terminal of the switching element 13a is connected to the negative electrode side wiring 102. (First series circuit).
Further, the anode of the reverse blocking diode 12b and the second terminal of the switching element 13b are connected, the cathode of the reverse blocking diode 12b is connected to the positive electrode side wiring 101, and the first terminal of the switching element 13b is connected to the negative electrode side wiring 102. (Second series circuit).
Further, the second terminal of the switching element 13a is connected to the second terminal of the reactor 14a via the coil 15a, and the first terminal of the reactor 14a is further connected to the first output terminal of the AC power supply 201.
The second terminal of the switching element 13b is connected to the second terminal of the reactor 14b via the coil 15b, and the first terminal of the reactor 14b is connected to the second output terminal of the AC power supply 201.

  In the above, there are reactors 14a and 14b (several mH) and coils 15a and 15b (several 10 μH) as elements having inductance, but the reactors 14a and 14b function as elements of the boost chopper circuit. The coils 15a and 15b are not directly used as a function of the step-up chopper circuit, but are used for another purpose to be described later.

This step-up chopper circuit has a rectifying function and a function for improving the power factor.
That is, a part of the diode bridge constituting the rectifier circuit is replaced with the switching elements 13a and 13b, and short-circuit opening (ON / OFF) is repeated so that the switching elements 13a and 13b are synchronously rectified (rectifying operation). By repeating this on / off, energy is accumulated and released in the reactors 14a and 14b provided between the AC power supply 201 and the reactor.
By controlling the switching elements 13a and 13b, current flows through the reverse blocking diode 12a and the switching element 13b in the positive half cycle of the AC power supply 201.

Further, in the negative half cycle of the AC power supply 201, a current flows through the reverse blocking diode 12b and the switching element 13a.
As for the switching elements 13a and 13b, MOSFETs (metal-oxide-semiconductor field-effect transistors) are used as the switching elements. Since there is no PN junction like a diode in the channel through which the MOSFET current flows, a rectifier circuit with a small voltage drop can be configured.
In addition, when a super junction MOSFET is used as the MOSFET, the voltage drop becomes smaller and the loss can be further reduced.
In the case of a MOSFET, an antiparallel parasitic diode is formed in the transistor (FIGS. 1, 13a, and 13b).

In the reactors 14a and 14b, a current determined by changes in inductance and voltage flows.
This current flows regardless of the voltage of the smoothing capacitor 16 due to the action of the reverse blocking diodes 12a and 12b. With this operation, a current can flow even in a section where the voltage of the AC power supply 201 is lower than the voltage of the smoothing capacitor 16.
In other words, as described above, by storing and releasing energy in the reactors 14a and 14b of this step-up chopper circuit, even in a section where the input voltage of the AC power supply 201 is small, there is almost no section where current flows at all. As shown, the current waveform can be made sinusoidal, and the power factor is improved.
Note that FIG. 8 will be described in detail again in Comparative Example 2 described later.

The reactors 14a and 14b are approximately several mH (1 mH or more and less than 10 mH) as described above. Further, the coils 15a and 15b are several tens of μH (10 μH or more and less than 100 μH) as described above.
Thus, it is important that the coils 15a and 15b have a sufficiently small inductance with respect to the reactors 14a and 14b.
As described above, the coils 15a and 15b connected in series to the switching elements 13a and 13b have a small inductance, and the back electromotive force of the coils 15a and 15b is small in the region where the current is small, thereby providing an effect of synchronous rectification. When the current is increased, the back electromotive force of the coils 15a and 15b is also increased, and there is a possibility that the synchronous rectification may be hindered. In practice, however, the rectifier diodes 11a to 11d are respectively connected to the boost chopper circuit as described above. Since they are connected in parallel, the current does not flow through the rectifier diodes 11a to 11d and the operation is not hindered.
The power factor improvement in the rectification operation by the rectifier diodes 11a to 11d depends on the functions of the reactors 14a and 14b as described above.
At this time, if the inductance values of the coils 15a and 15b are close to the inductance values of the reactors 14a and 14b, the counter electromotive force generated in the coils 15a and 15b may interfere with the rectification operation by the rectifier diodes 11a to 11d. Therefore, it is desirable that the inductance values of the coils 15a and 15b are sufficiently small with respect to the inductance values of the reactors 14a and 14b.

As described above, the boost chopper circuit has a function of synchronous rectification and a power factor improvement function as long as the switching elements 13a and 13b are appropriately controlled to be turned on / off.
The switching elements 13a and 13b of the step-up chopper circuit are turned on / off by pulse width control (PWM). By combining the pulse width and timing, only the above-described synchronous rectification function and power factor improvement function can be used. In addition, there is a function of boosting (variable voltage) the voltage value of the rectified DC voltage.
Further, illustration of a control circuit for turning on and off the switching elements 13a and 13b is omitted.

《Reverse recovery current countermeasure configuration》
When the switching elements 13a and 13b are turned off from on, a current in the reverse direction may flow through the reverse blocking diodes 12a and 12b instantaneously. This is because carriers accumulated in the vicinity of the PN junctions of the reverse blocking diodes 12a and 12b are discharged when the applied voltage is reversed.
This phenomenon in which a reverse current flows is called a reverse recovery current, but the flow of the reverse recovery current results in a loss of energy, and the efficiency of the power supply device decreases.

The first measure for reducing the reverse recovery current is to use a fast recovery diode with a low reverse recovery current or a wide-gap semiconductor Schottky barrier diode such as SiC (Silicon Carbide) for the reverse blocking diodes 12a and 12b. It is.
However, the diode has a good reverse recovery current, but has a large forward voltage drop.
Therefore, the reverse blocking diode having a small reverse recovery current is not used in the following.
By using reverse blocking diodes 12a and 12b of a type with a small voltage drop in the forward direction, the reverse recovery current is suppressed by means of a circuit described below.

A second measure for suppressing the reverse recovery current by means of a circuit will be described.
As shown in FIG. 1, the coils 15a and 15b are connected between the anode of the rectifier diode 11a and the anode of the reverse blocking diode 12a, and between the anode of the rectifier diode 11c and the anode of the reverse blocking diode 12b, respectively.
For example, when the switching element 13a is turned on while a current is flowing in the rectifier diode 11a, a reverse recovery current is generated in the rectifier diode 11a. This reverse recovery current is reversed by the coil 15a by flowing through the coil 15a. An electromotive force is generated and the reverse recovery current is suppressed.
When the reverse recovery phenomenon of the diode (rectifier diode 11a) ends, the reverse recovery current disappears. The extinguished reverse recovery current energy is stored in the coil 15a. The energy of the reverse recovery current accumulated in the coil 15a is released (recovered) to the smoothing capacitor 16 when the switching element 13a is turned off, and does not cause a loss.

  Similarly, the reverse recovery current caused by turning on the switching element 13a in the reverse blocking diode 12a is also accumulated in the coil 15a. When the switching element 13a is turned off, the reverse recovery current is opened (collected) to the smoothing capacitor 16 and does not cause a loss.

Further, the reverse recovery current and the energy of the rectifier diode 11b and the reverse blocking diode 12b when the switching element 13b is turned on / off are recovered by the action of the coil 15b and do not cause a loss.
Therefore, in the power supply device 10 of the first embodiment, the rectifier diodes 11a and 11b and the reverse blocking diodes 12a and 12b employ rectifier diodes that have a large reverse recovery current but a small voltage drop, and suppress the reverse recovery current. Can be used.

Note that “rectifier diode” and “reverse blocking diode” are given different names depending on their main circuit functions, but they are still diodes, and in the circuit of FIG. 1, reverse recovery current can be generated. Sex is the same.
The reactors 14a and 14b are several mH as described above, while the coils 15a and 15b are several tens of μH.
Here, as described above, the inductances of the reactors 14a and 14b are characterized by being sufficiently larger than the inductances of the coils 15a and 15b. However, the respective inductances are examples, and the sizes are not limited.
The reactors 14a and 14b are mainly used for rectification, while the coils 15a and 15b are used to reduce the reverse recovery current of the diodes (reverse blocking diodes and rectifier diodes) as described above. It is used to suppress the influence of
The reactors 14a and 14b and the coils 15a and 15b are both elements having inductance, but there are differences between several mH and several tens of μH as described above, and the main functions are also the reactors 14a and 14b (rectifying action, boost chopper) There is a difference between the action, power factor improvement action) and the coils 15a and 15b (reverse recovery current reduction action and inrush current suppression action described below), so different names are used to clarify the difference. ing.

《Inrush current countermeasure configuration》
In the circuit of FIG. 1, an inrush current flows from the AC power supply 201 to the smoothing capacitor 16 via the rectifier diodes 11a, 11b, 11c, and 11d when the power is turned on.
In addition, an excessive current may flow through the boost chopper circuit including the reverse blocking diodes 12a and 12b and the switching elements 13a and 13b.
The switching elements 13a and 13b are more likely to be destroyed than the rectifier diodes (11a to 11d). In particular, when MOSFETs are used as the switching elements 13a and 13b, there is a gate film that is thin and has a low withstand voltage.
Further, the reverse blocking diodes 12a and 12b may be more likely to be destroyed than the rectifier diodes (11a to 11d).
As countermeasures, coils 15a and 15b are provided.

  Since the coils 15a and 15b are inserted in series with respect to the switching elements 13a and 13b, the inductance of the coils 15a and 15b is several tens of μH. Electric power is generated to suppress the inrush current.

Further, since the boost chopper circuits (12a, 12b, 13a, 13b) are connected in parallel with the rectifier circuits (rectifier diodes 11a, 11b, 11c, 11d), the inrush current is shunted.
Since the inrush current is shunted, the possibility that the switching elements 13a and 13b and the reverse blocking diodes 12a and 12b of the boost chopper circuit are destroyed is reduced.

  The switching elements 13a and 13b and the reverse blocking diodes 12a and 12b of the step-up chopper circuit are destroyed by the suppression action of the coils 15a and 15b and the shunt action of the rectifier circuits (rectifier diodes 11a, 11b, 11c, and 11d). The risk of being reduced is greatly reduced.

<Effects of Power Supply Device of First Embodiment>
As described above, the power supply device 10 of FIG. 1 has a power factor improving function, suppresses an excessive inrush current generated when the power is turned on, suppresses a reverse recovery current of the reverse blocking diode, reduces a voltage drop, and has a high efficiency. Power supply. Further, since the inrush current is suppressed, the safety is high and the voltage loss and the power loss are small, so that the power supply device can be downsized.

(Comparative example)
Next, in order to show how the power supply device according to the first embodiment of the present invention is superior to the prior art, an example of another rectifying / smoothing circuit is shown as a comparative example.

<Comparative Example 1>
As Comparative Example 1, a capacitor input rectifying and smoothing circuit having the configuration shown in FIG. 5 will be described with reference to FIG. 2 to 4 will be described later as an embodiment of the present invention.
FIG. 5 is a diagram showing a circuit configuration of a first example of a capacitor input rectifying / smoothing circuit that receives an AC power supply and generates a DC voltage (power).
FIG. 7 is a diagram showing voltage waveforms and current waveforms on the input side of the capacitor input rectifying and smoothing circuit shown in FIG. 6 will be described later as a comparative example 2.
In FIG. 5, a rectifier circuit is configured with rectifier diodes 11a to 11d as diode bridges.

The AC power supply 201 supplies an AC voltage (power) to the first and second AC input terminals of the rectifier circuit.
The rectifier circuits (rectifier diodes 11 a to 11 d) rectify an AC voltage and supply a voltage (power) mainly composed of a DC component to the smoothing capacitor 16 via the positive electrode side wiring 101 and the negative electrode side wiring 102.
The voltage (power) smoothed by the smoothing capacitor 16 is supplied to the load 202.
The capacitor input rectifying and smoothing circuit shown in FIG. 5 has a current (characteristic line 1002: FIG. 7) in a region where the voltage (characteristic line 1001: FIG. 7) applied between the first AC input terminal and the second AC input terminal is small. There is a section where 7) does not flow.
Since there is a section where no current flows, there is a problem that the current waveform is greatly different from a sine wave, and the power factor is lowered.

<Comparative Example 2>
As Comparative Example 2, a capacitor input rectifying and smoothing circuit having the configuration shown in FIG. 6 will be described with reference to FIG.
FIG. 6 is a diagram illustrating a circuit configuration of a second example of the capacitor input rectifying / smoothing circuit that receives an AC power supply and generates a DC voltage (power).
FIG. 8 is a diagram showing voltage waveforms and current waveforms on the input side of the capacitor input rectifying and smoothing circuit shown in FIG.
In FIG. 6, a part of the rectifier circuit (rectifier diodes 11a to 11d) in FIG. 5 is replaced with switching elements (13e, 13f), and reactors 14a, 14b are connected between the switching elements (13e, 13f) and the AC power supply 201. And a rectifying / smoothing circuit for improving the power factor by a boost chopper.

In the reactors 14a and 14b, a quantity of electricity determined by changes in inductance and voltage flows.
This current flows regardless of the voltage of the smoothing capacitor 16 due to the action of the reverse blocking diodes 12a and 12b. By this operation, a current (characteristic line 1003: FIG. 8) can flow even in a section where the voltage of the AC power supply 201 is lower than the voltage of the smoothing capacitor 16.
In other words, by storing and releasing energy in the reactors 14a and 14b of the boost chopper circuit, there is almost no section where current flows even in a section where the input voltage of the AC power supply 201 is small. As shown in FIG. Can be made sinusoidal to improve the power factor.

However, in the capacitor input rectifying / smoothing circuit shown in FIG. 6, since the smoothing capacitor 16 is not charged when the power is turned on, a large current flows when the power is turned on.
This is called inrush current. In general, the rectifier diode used in the capacitor input rectifying and smoothing circuit of FIG. 5 is a rectifier diode having a non-repetitive surge withstand capability that can withstand this inrush current.
However, the switching elements 13e and 13f and the reverse blocking diodes 12e and 12f have a problem that the surge resistance is low, and there is a possibility that the switching elements 13e and 13f and the reverse blocking diodes 12e and 12f may be destroyed by an inrush current when the power is turned on.

<Comparative Example 3>
As Comparative Example 3, a capacitor input rectifying and smoothing circuit having the configuration shown in FIG. 9 will be described.
FIG. 9 is a diagram illustrating a circuit configuration of a third example of the capacitor input rectifying / smoothing circuit that receives an AC power supply and generates a DC voltage (power). Further, a technique similar to Patent Document 1 is disclosed.
In FIG. 9, rectifier diodes 11a and 11c are provided to reduce inrush currents flowing through the switching elements 13e and 13f and the reverse blocking diodes 12e and 12f.
However, when the rectifier diodes 11a and 11c are provided as shown in FIG. 9, most of the power source current flows through the rectifier diodes 11a and 11c due to the counter electromotive force generated in the reactors 14a and 14b.

Each series circuit of the switching elements 13e and 13f and the reactors 14a and 14b cannot operate with a voltage drop smaller than that of the rectifier diodes 11a and 11c. For this reason, the power supply device shown in FIG. 9 must always switch the switching elements 13e and 13f.
Therefore, even when the input power from the AC power supply 201 is small, it is necessary to perform the switching operation, and the energy loss due to the switching operation substantially exceeds the power factor improvement effect when the input power is small. There is a problem that it is not a good idea.

<Comparative example 4>
As Comparative Example 4, a capacitor input rectifying and smoothing circuit having the configuration shown in FIG. 10 will be described.
FIG. 10 is a diagram illustrating a circuit configuration of a fourth example of the capacitor input rectification smoothing circuit that receives an AC power supply and generates a DC voltage (power).
FIG. 12 is a diagram showing that a reverse recovery current (characteristic line 2004) flows in the circuit of FIG. FIG. 11 will be described later as Comparative Example 5.
In FIG. 10, the AC voltage is rectified by the rectifier diodes 11a to 11d and a voltage mainly composed of a direct current component is output to the positive electrode side wiring 111 and the negative electrode side wiring 102. A boosting chopper consisting of 25 is provided to improve the power factor, and a rectifying and smoothing circuit that outputs a DC voltage (power) to the smoothing capacitor 16 is configured. A voltage (electric power) is supplied to the load 202 from the positive electrode side wiring 121 and the negative electrode side wiring 102 at both ends of the smoothing capacitor 16.

Here, the principle of the boost chopper and the operation of the reverse blocking diode 5 will be described.
As shown in FIG. 10, when the full-wave rectified waveform is short-circuited in the reactor 24 via the switching element 26, a current that increases with a slope determined by the voltage and the inductance of the reactor 24 flows.
This current flows regardless of the voltage of the smoothing capacitor 16 due to the action of the reverse blocking diode 25. By this operation, a current can flow even during a period in which the voltage of the AC power supply 201 is lower than the voltage of the smoothing capacitor 16, and a current waveform as shown in FIG. 8 can be obtained.
When the switching element 26 is turned off, no current flows through the switching element 26, but the current in the reactor 24 cannot be changed steeply (in this case, decreased) due to the inertia of the inductance.

Therefore, the reactor 24 generates a counter electromotive force in order to keep the current flowing, and flows a current for charging the smoothing capacitor 16 via the reverse blocking diode 25. By repeating this operation, the current waveform can be made sinusoidal.
When the switching element 26 is turned on from off, a current in the reverse direction flows through the reverse blocking diode 25 instantaneously. This is called reverse recovery current. As shown in FIG. 12, the reverse recovery current (characteristic line 2004) is superimposed on the current of the reactor 24 and flows through the switching element 26.
This reverse recovery current (characteristic line 2004) has a problem that voltage loss and power loss occur in the circuit of FIG.

<Comparative Example 5>
As Comparative Example 5, a capacitor input rectifying and smoothing circuit having the configuration shown in FIG. 11 will be described.
FIG. 11 is a diagram illustrating a circuit configuration of a fifth example of the capacitor input rectifying / smoothing circuit that receives an AC power supply and generates a DC voltage (power).
FIG. 13 is a diagram showing that the reverse recovery current (characteristic line 2004) no longer flows (characteristic line 2005) in the circuit of FIG.
In FIG. 11, a coil 15 and a diode 29 are further provided between the switching element 26 and the reverse blocking diode 25 in the circuit of FIG. This is to reduce the reverse recovery current of the reverse blocking diode 25 in the circuit of FIG.
As described above, the current flowing through the inductance does not like a sharp change. If an inductance is inserted in a path through which a steep current such as a reverse recovery current flows, a reverse machine voltage is generated and the current can be suppressed.
That is, in FIG. 11, since the coil 15 also acts on the current of the reactor 24, the diode 29 is connected in parallel with the coil 15 to bypass the current. The reverse recovery current of the reverse blocking diode 25 flows through the coil 15. At this time, a counter electromotive force is generated in the coil 15 to suppress the reverse recovery current (characteristic line 2005: FIG. 13).

As described above, although the reverse recovery current is suppressed, when the reverse recovery current disappears, the return current flows through the diode 29 by the action of the inductance of the coil 15.
The energy due to this current is consumed and lost due to the voltage drop of the resistance of the coil 15 and the diode 29, and there is a problem that the efficiency of the power supply device is lowered.

(Second Embodiment / Power Supply Device)
Next, the power supply device which is 2nd Embodiment of this invention is demonstrated with reference to FIG.
FIG. 2 is a diagram illustrating a circuit configuration of a power supply device according to a second embodiment of the present invention and a connection relationship between the power supply device and an electric compressor including a motor. In addition, FIG. 2 is also a figure which serves as description of the air conditioner of 5th Embodiment mentioned later.
A power supply device 20 in FIG. 2 is provided with an inverter 17 for converting a DC voltage (power) into an AC voltage (power) having a variable frequency and voltage in addition to the power supply device 10 of the first embodiment shown in FIG. It is.
The power supply device 10 of the first embodiment shown in FIG. 1 is a power supply device that receives an AC voltage (power) from an AC power supply and outputs a DC voltage (power), whereas FIG. The power supply device 20 of the second embodiment is a power supply device that receives an AC voltage (power) from, for example, a commercial AC power supply and outputs an AC voltage (power) having a variable frequency and voltage.

In FIG. 2, the inverter 17 is configured to include switching elements 18a, 18b, 18c, 18d, 18e, and 18f made of MOSFETs.
The switching element 18a as the upper arm and the switching element 18b as the lower arm constitute a U-phase switching leg.
The switching element 18c serving as the upper arm and the switching element 18d serving as the lower arm constitute a V-phase switching leg.
The switching element 18e serving as the upper arm and the switching element 18f serving as the lower arm constitute a W-phase switching leg.
The above U-phase, V-phase, and W-phase switching legs are supplied with DC voltage (electric power) using the positive-side wiring 101 and the negative-side wiring 102 connected to the smoothing capacitor 16 as power sources.
Then, by controlling the control terminals (gate terminals) of the switching elements 18a, 18b, 18c, 18d, 18e, and 18f respectively by a control circuit (not shown), switching of the U phase, the V phase, and the W phase is performed. A three-phase AC voltage (power) is output from the leg by a U-phase AC output 103U, a V-phase AC output 103V, and a W-phase AC output 103W.

Note that the three-phase AC voltage (power) output from the inverter 17 becomes a variable frequency when the control circuit performs predetermined control of the inverter 17.
In addition, by controlling on / off the switching elements 13a and 13b of the boost chopper circuit (12a, 12b, 13a, 13b, 14a, 14b, 15a, and 15b), the voltage across the smoothing capacitor 16 is Since the DC voltage is variable, the voltage amplitude of the three-phase AC voltage (electric power) of the inverter 17 using the DC voltage of the smoothing capacitor 16 as a power source is also variable.
The three-phase AC voltage (voltage) output from the inverter 17 is supplied to an electric compressor 203 provided with a motor (electric motor).
The control circuit that controls the inverter 17 and the control circuit that controls the switching of the switching elements 13a and 13b of the step-up chopper circuit are preferably integrated control circuits.
2 is different from the power supply device 10 of the first embodiment of FIG. 1 only in the configuration of the inverter 17, as described above, the power supply device 10 of the first embodiment of FIG. A duplicate description is omitted.

  2 has a circuit for generating a DC voltage (electric power) in common with the power supply apparatus 10 of FIG. 1, the power supply apparatus 20 of FIG. 2 also has a power factor improving function. In addition, it suppresses the excessive inrush current that occurs when the power is turned on, suppresses the reverse recovery current of the reverse blocking diode, and has a low voltage drop, high safety, high efficiency, variable frequency, variable voltage three-phase AC The power supply device outputs voltage (power).

(Third embodiment: power supply device)
A power supply device according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a diagram showing a circuit configuration of the power supply device 30 according to the third embodiment of the present invention.
The power supply device 30 of FIG. 3 is a modification of the circuit configuration of FIG. 1 based on substantially the same principle as the power supply device 10 of FIG.
In FIG. 3, the power supply device 30 includes a reactor 14, rectifier diodes 11a, 11b, 11c, and 11d, coils 15c and 15d, reverse blocking diodes 12c and 12d, switching elements 13c and 13d, and a smoothing capacitor 16. .
In claim 2, the rectifier diodes 11a, 11b, 11c, and 11d correspond to the first, second, third, and fourth diodes, respectively, in order. The coils 15c and 15d correspond to a second coil and a first coil, respectively. The reverse blocking diodes 12c and 12d correspond to sixth and fifth diodes, respectively. The switching elements 13c and 13d correspond to a second switching element and a first switching element, respectively.

The configuration of the rectifier circuit including the rectifier diodes 11a, 11b, 11c, and 11d is the same as that in FIG.
Only one reactor 14 is provided and connected between the first output terminal of the AC power supply 201 and the connection point (first AC input terminal) of the rectifier diode 11c and the rectifier diode 11d.
The second output terminal of the AC power supply 201 is connected between the connection point (second AC input terminal) of the rectifier diode 11a and the rectifier diode 11b.
The second terminal (drain electrode) of the switching element 13c (N-type MOFET) is connected to the positive electrode side wiring 101, and the first terminal (source electrode) is connected to the reactor 14 via the coil 15c.
The first terminal (source electrode) of the switching element 13d (N-type MOFET) is connected to the negative electrode side wiring 102, and the second terminal (drain electrode) is connected to the reactor 14 via the coil 15d.

The cathode of the reverse blocking diode 12c is connected to the first terminal of the switching element 13c. Further, the anode of the reverse blocking diode 12c is connected to the negative-side wiring 102 (second series circuit).
The anode of the reverse blocking diode 12d is connected to the second terminal of the switching element 13d. Further, the cathode of the reverse blocking diode 12d is connected to the positive electrode side wiring 101 (first series circuit).
The smoothing capacitor 16 is connected between the positive electrode side wiring 101 and the negative electrode side wiring 102.
Further, the DC voltage (electric power) of the smoothing capacitor 16 is supplied to the load 202 via the positive electrode side wiring 101 and the negative electrode side wiring 102.
The power supply device 30 (third embodiment) is configured by the above circuit.

Next, the operation of the boost chopper in the circuit of FIG. 3 will be described.
In the positive half cycle of the AC power supply 201, the current flows through the reactor 14 and the rectifier diode 11c, charges the smoothing capacitor 16, and flows through the rectifier diode 11b back to the AC power supply 201.
When the switching element 13d is turned on, the current in the reactor 14 flows through the switching element 13d via the coil 15d. At this time, a reverse recovery current flows through the rectifier diode 11c, but is suppressed by the action of the coil 15d.

  Note that a fast recovery diode with a small reverse recovery current can be used for the reverse blocking diode 12d (and 12c) in order to recover the reverse recovery current quickly.

Similar to the power supply device 10 of the first embodiment shown in FIG. 1, the inductance of the coil 15 d is small and no reverse recovery current flows if the current disappears.
The operation for improving the power factor by the operation of the step-up chopper by turning on / off the switching element 13d is the same as that of the power supply device 10 of the first embodiment.
The above description is about the positive half cycle of the AC power supply 201. However, the same operation is performed in the switching element 13c, the coil 15c, the reverse blocking diode 12c, the reactor 14, and the rectifier diode 11c even in the negative half cycle. Thus, the same is true for suppressing reverse recovery current and performing power factor improvement. In practice, duplicate descriptions are omitted.

Also in the power supply device 30 of the third embodiment shown in FIG. 3, the reverse recovery currents of the reverse blocking diodes 12c and 12d are suppressed by the action of the coils 15c and 15d. Since the coils 15c and 15d have the action, it is not necessary to use a fast recovery diode with a small reverse recovery current for the reverse blocking diodes 12c and 12d.
Moreover, the inrush current to the reverse blocking diodes 12c and 12d and the switching elements 13c and 13d can be suppressed by the action of the coils 15c and 15d.

  Also in the power supply device 30 of the third embodiment, if a super junction MOSFET is used for the switching elements 13a and 13b, loss can be reduced by synchronous rectification.

(Fourth embodiment, power supply device)
Next, the power supply device which is 4th Embodiment of this invention is demonstrated with reference to FIG.
FIG. 4 is a diagram illustrating a circuit configuration of a power supply device 40 according to the fourth embodiment of the present invention and a connection relationship between the power supply device 40 and an electric compressor 203 including a motor. FIG. 4 is also a diagram that also serves as an explanation of an air conditioner according to a sixth embodiment to be described later.
The power supply device 40 in FIG. 4 includes the inverter 17 that converts the DC voltage (power) into an AC voltage (power) having a variable frequency and voltage in addition to the power supply device 30 of the third embodiment shown in FIG. It is.
The power supply device 30 of the third embodiment shown in FIG. 3 is a power supply device that receives an AC voltage (power) from an AC power supply and outputs a DC voltage (power), whereas FIG. The power supply device 40 of the fourth embodiment is a power supply device that receives an AC voltage (power) from, for example, a commercial AC power supply and outputs an AC voltage (power) having a variable frequency and voltage.

In FIG. 4, the inverter 17 is the same as the inverter 17 described in FIG. That is, the inverter 17 outputs a three-phase AC voltage (power) having a variable frequency.
Since the power supply device 40 of the fourth embodiment includes a step-up chopper circuit similarly to the power supply device 30 of the third embodiment, the three-phase AC voltage of the inverter 17 that uses the DC voltage of the smoothing capacitor 16 as a power source. The voltage amplitude of (power) is also variable.
The variable frequency, variable voltage three-phase AC voltage (voltage) output from the inverter 17 is supplied to an electric compressor 203 having a motor (electric motor).
In addition, the power supply device 40 of 4th Embodiment in FIG. 4 combined the power supply device 30 of 3rd Embodiment of FIG. 3 and the inverter 17 in the power supply device 20 of 2nd Embodiment of FIG. 2 as mentioned above. It is. Therefore, the overlapping description is omitted.

  4 has a circuit for generating a DC voltage (power) in common with the power supply device 30 of FIG. 3, the power supply device 40 of FIG. 4 also has a power factor improving function. In addition, it suppresses the excessive inrush current that occurs when the power is turned on, suppresses the reverse recovery current of the reverse blocking diode, and has a low voltage drop, high safety, high efficiency, variable frequency, variable voltage three-phase AC The power supply device outputs voltage (power).

(Fifth embodiment / air conditioner)
The air conditioner which is 5th Embodiment of this invention is demonstrated with reference to FIG.
FIG. 2 shows a connection relationship between the power supply device 20 of the second embodiment and the electric compressor 203 provided with a motor.
The power supply device 20 and the electric compressor 203 are provided in the air conditioner.
The air conditioner is provided with a refrigerating cycle (not shown) that is composed of an outdoor heat exchanger, a decompressor, an indoor heat exchanger, and a four-way valve by compressing a refrigerant with an electric compressor 11.
Moreover, the air blower is provided with respect to each heat exchanger. The refrigerant is compressed by the electric compressor 203. In the outdoor unit, the outdoor heat exchanger exchanges heat with the outdoor air by blowing from the blower. In the indoor unit, the indoor heat exchanger sends air from the blower. Heat exchange with air.
Switching between cooling and heating is performed by reversing the direction of refrigerant circulation using a four-way valve.

As described above, the electric compressor 203 is driven by the variable voltage and variable frequency three-phase alternating current supplied by the power supply device 20.
That is, by using the power supply device 20 of the second embodiment (or the power supply device 10 of the first embodiment) for the air conditioner, the power factor of the power supply current is improved even for the air conditioner.
Further, since the DC voltage can be boosted inside the power supply device 20 of the second embodiment (or the power supply device 10 of the first embodiment), the efficiency as an air conditioner can be improved.
In the region where the input current is small, the efficiency can be improved as an air conditioner.
In addition, since the reverse recovery current can be suppressed, the generation of noise can be suppressed, and noise countermeasure parts can be reduced as an air conditioner.

(Sixth embodiment, air conditioner)
The air conditioner which is 6th Embodiment of this invention is demonstrated with reference to FIG.
In FIG. 4, the connection relationship between the power supply apparatus 40 of 4th Embodiment and the electric compressor 203 provided with the motor is shown.
The power supply device 40 and the electric compressor 203 are provided in the air conditioner.
The power supply device 40 has been described in the fourth embodiment.
The air conditioner provided with the electric compressor 203 has been described in the fifth embodiment.
The air conditioner which is 6th Embodiment is the structure and effect | action similar to the air conditioner of 5th Embodiment except mounting the power supply device 40 of 4th Embodiment.
The power supply device 40 mounted in the sixth embodiment has substantially the same operations, functions, and effects as the power supply device 20 mounted in the fifth embodiment.
Therefore, the air conditioner according to the sixth embodiment has substantially the same functions, functions, and effects as the air conditioner according to the fifth embodiment.
In practice, duplicate descriptions are omitted.

(Other embodiments)
As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, this invention is not limited to these embodiment and its deformation | transformation, There exists a design change etc. of the range which does not deviate from the summary of this invention. Well, here are some examples:

<Switching element of IGBT>
When the power supply device according to the second embodiment has been described with reference to FIG. 2, the switching elements constituting the inverter 17 have been described as MOSFETs. However, the switching elements constituting the inverter 17 are not limited to MOSFETs.
The switching element forming the inverter 17 may be an IGBT. A super junction MOSFET may also be used.

<Three-phase AC power supply>
Although the case where the AC power supply 201 is a single phase has been described with reference to FIG. 1, it may be a three-phase case. In this case, at least the set of rectifier diodes 11a to 11d and the set of reactors 14a and 14b are each three sets (for U, V, and W phases).

<Devices other than air conditioners>
In 5th, 6th embodiment, the case where the power supply device of 1st-4th embodiment was mounted in an air conditioner was demonstrated.
However, since the power supply device of the first and third embodiments is a power supply device that obtains a DC voltage (power) from the AC voltage (power) of the AC power supply, It is not limited to air conditioners. Devices that directly or indirectly use DC voltage (electric power) are widely available and applicable.
Moreover, since the power supply apparatus of 2nd, 4th embodiment is a power supply apparatus which obtains a variable voltage and a variable frequency three-phase alternating current voltage (electric power) from the alternating voltage (electric power) of commercial alternating current power supply, for example, this power supply apparatus The device that is effective by mounting is not limited to an air conditioner.
A motor is driven based on a three-phase AC voltage (electric power) having a variable voltage and a variable frequency, and devices equipped with this motor are widely available and applicable.

10, 20, 30, 40 Power supply device 11a, 11b, 11c, 11d Rectifier diode 12a, 12b, 12c, 12d Reverse blocking diode 13a, 13b, 13c, 13d Switching element (MOSFET)
14, 14a, 14b Reactor 15a, 15b Coil 16 Smoothing capacitor 17 Inverter 18a, 18b, 18c, 18d, 18e, 18f Switching element 101 Positive side wiring 102 Negative side wiring 201 AC power source 202 Load 203 Electric compressor (motor)

Claims (8)

A diode bridge is configured by including first, second, third, and fourth diodes, a connection point between the anode of the first diode and the cathode of the second diode is a first AC input terminal, and A connection point between the anode and the cathode of the fourth diode is a second AC input terminal, a connection point between the cathode of the first diode and the cathode of the third diode is connected to a positive-side wiring, and the anode of the second diode A rectifier circuit formed by connecting a connection point of the anode of the fourth diode to a negative electrode side wiring;
An anode of the fifth diode and a second terminal of the first switching element are connected, a cathode of the fifth diode is connected to the positive electrode side wiring, and a first terminal of the first switching element is connected to the negative electrode side wiring. A first series circuit comprising:
An anode of the sixth diode and a second terminal of the second switching element are connected, a cathode of the sixth diode is connected to the positive side wiring, and a first terminal of the second switching element is connected to the negative side wiring. A second series circuit comprising:
A smoothing capacitor connected between the positive electrode side wiring and the negative electrode side wiring;
A first reactor connected between a first output terminal of an AC power supply and a first AC input terminal of the rectifier circuit;
A second reactor connected between a second output terminal of the AC power source and a second AC input terminal of the rectifier circuit;
A first coil connected between a second terminal of the first switching element and a first AC input terminal of the rectifier circuit;
A second coil connected between a second terminal of the second switching element and a second AC input terminal of the rectifier circuit;
A power supply apparatus comprising: A diode bridge is configured by including first, second, third, and fourth diodes, a connection point between the anode of the first diode and the cathode of the second diode is used as a second AC input terminal, and the third diode A connection point between the anode and the cathode of the fourth diode is a first AC input terminal, a connection point between the cathode of the first diode and the cathode of the third diode is connected to a positive-side wiring, and the anode of the second diode A rectifier circuit formed by connecting a connection point of the anode of the fourth diode to a negative electrode side wiring;
An anode of the fifth diode and a second terminal of the first switching element are connected, a cathode of the fifth diode is connected to the positive electrode side wiring, and a first terminal of the first switching element is connected to the negative electrode side wiring. A first series circuit comprising:
The cathode of the sixth diode and the first terminal of the second switching element are connected, the anode of the sixth diode is connected to the negative side wiring, and the second terminal of the second switching element is connected to the positive side wiring. A second series circuit comprising:
A smoothing capacitor connected between the positive electrode side wiring and the negative electrode side wiring;
A reactor connected between a first output terminal of an AC power source and a first AC input terminal of the rectifier circuit;
A first coil connected between a second terminal of the first switching element and a first AC input terminal of the rectifier circuit;
A second coil connected between a first terminal of the second switching element and a first AC input terminal of the rectifier circuit;
With
A power supply apparatus comprising: a second output terminal of an AC power supply connected to a second AC input terminal of the rectifier circuit. The power supply device according to claim 1 or 2,
further,
A power supply apparatus comprising: an inverter that inputs a DC voltage of the smoothing capacitor through the positive electrode side wiring and the negative electrode side wiring, converts the voltage into a three-phase AC voltage having a variable frequency, and outputs the voltage. In any one of Claims 1 thru | or 3,
The power supply apparatus, wherein the first switching element and the second switching element are made of MOSFETs. In claim 4,
The power supply apparatus, wherein the MOSFET is a super junction MOSFET. In any one of Claims 1 thru | or 3,
The reactor has an inductance value of 1 mH or more and less than 10 mH, and the coil has an inductance value of 10 μH or more and less than 100 μH. In any one of Claims 1 thru | or 3,
The fifth and sixth diodes are fast recovery diodes or wide-gap semiconductor Schottky barrier diodes. An air conditioner comprising the power supply device according to any one of claims 1 to 7.

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