WO2022180747A1

WO2022180747A1 - Power supply device

Info

Publication number: WO2022180747A1
Application number: PCT/JP2021/007171
Authority: WO
Inventors: 貴寛平田
Original assignee: 三菱電機株式会社
Priority date: 2021-02-25
Filing date: 2021-02-25
Publication date: 2022-09-01
Also published as: JP7370492B2; JPWO2022180747A1

Abstract

A supply device (101) comprises: a converter unit (13A); an inverter unit (14); a bus voltage detection unit (17) that detects the voltage value of a DC voltage supplied to the inverter unit (14); a compressor current detection unit (18) that detects the current value of current flowing through a motor; and a microcomputer (16) that controls the converter unit (13A). The converter unit (13A) includes reactors (La, Lb), a diode bridge (4), smoothing capacitors (Ca, Cb), a relay (Ra1) that executes switching as to which of the reactors (La, Lb) is to be connected to a commercial AC power source (1), and relays (Rb1, Rc1) that execute switching as to which of the smoothing capacitors (Ca, Cb) is to be connected to the diode bridge (4) and the inverter unit (14). The microcomputer (16) controls the relays (Ra1, Rb1, Rc1) on the basis of the voltage value detected by the bus voltage detection unit (17) and the current value detected by the compressor current detection unit (18).

Description

power supply

The present disclosure relates to a power supply device that rectifies an AC voltage to generate a DC voltage.

One type of power supply that rectifies an AC voltage to generate a DC voltage is a power supply that drives a motor using an inverter system. This power supply device is applied to air conditioners and the like.

The power supply device described in Patent Document 1 rectifies a commercial AC voltage from a commercial power supply with a diode bridge connected to a reactor and smoothes it with a smoothing capacitor to generate a DC voltage. This DC voltage is supplied from the inverter to the motor as a power supply voltage.

JP-A-11-289766

However, in the technique of Patent Document 1, the reactor and smoothing capacitor connected to the diode bridge are fixed regardless of the size of the load, and the generated DC voltage cannot be changed. Therefore, the DC voltage is constant regardless of the characteristics of the motor and the operating range, so that the DC voltage is distorted under the influence of the operating frequency and the characteristics of the motor. As a result, power source resonance occurs depending on the characteristics and use environment of the power source device and the electric motor, and there is a problem that the operation of the motor by the power source device becomes unstable.

The present disclosure has been made in view of the above, and aims to obtain a power supply device that can stably operate a motor.

In order to solve the above-described problems and achieve the object, the power supply device of the present disclosure includes a converter section that converts the AC voltage of the commercial AC power source into a DC voltage, and a converter section that converts the DC voltage from the converter section into an AC voltage. An inverter section for driving the motor, a voltage detection section for detecting the voltage value of the DC voltage supplied to the inverter section, a current detection section for detecting the value of current flowing through the motor, and a control device for controlling the converter section. . The converter section includes a plurality of reactors that can be connected to a commercial AC power supply and have different inductance values, and rectifies the AC voltage from the commercial AC power supply while being connected to the commercial AC power supply through one of the plurality of reactors. a rectifying circuit that generates a voltage; and a plurality of smoothing capacitors having different capacitor capacities that are connectable to the rectifying circuit and the inverter unit, smooth the DC voltage while connected to the rectifying circuit and the inverter unit, and send the DC voltage to the inverter unit. have The converter section has a first switching section for switching which of the plurality of reactors is connected to the commercial AC power supply, and a second switching section for switching which of the plurality of smoothing capacitors is to be connected to the rectifier circuit and the inverter section. and a switching unit. The control device controls the first switching section and the second switching section based on the voltage value detected by the voltage detection section and the current value detected by the current detection section.

The power supply device according to the present disclosure has the effect of stably driving the motor.

1 shows a configuration of a power supply device according to a first embodiment; FIG. FIG. 2 is a diagram showing a configuration of a microcomputer included in the power supply device according to the first embodiment; 4 is a flowchart showing the procedure of first control processing by the power supply device according to the first embodiment; 4 is a flowchart showing the processing procedure of second control processing by the power supply device according to the first embodiment; FIG. 4 shows a configuration of a power supply device according to a second embodiment; FIG. 10 is a flow chart showing a processing procedure of third control processing by the power supply device according to the second embodiment; FIG. FIG. 4 is a diagram showing a configuration example of a processing circuit provided in the microcomputer according to the first and second embodiments when the processing circuit is implemented by a processor and a memory; FIG. 4 is a diagram showing an example of a processing circuit when the processing circuit included in the microcomputer according to the first and second embodiments is configured with dedicated hardware;

A power supply device according to an embodiment of the present disclosure will be described in detail below with reference to the drawings.

Embodiment 1.
1 is a diagram illustrating a configuration of a power supply device according to a first embodiment; FIG. The power supply device 101 is a device that rectifies an AC voltage to generate a DC voltage (hereinafter referred to as a DC voltage Vdc) and converts the DC voltage Vdc into an AC voltage. The power supply device 101 drives the compressor motor 15 by the inverter section 14 which is a load. A compressor motor 15, which is an example of an electric motor, is a motor applied to an air conditioner or the like.

The power supply device 101 includes a converter section 13A that converts the AC voltage of the commercial AC power supply 1 into a DC voltage Vdc, and an inverter section 14 that drives the compressor motor 15 by an inverter system. The inverter unit 14 converts the DC voltage Vdc from the converter unit 13A into an AC voltage and supplies the AC voltage to the compressor motor 15 .

The power supply device 101 also includes a bus voltage detection section 17 that detects the DC voltage Vdc from the converter section 13A, and a compressor current detection section 18 that detects the current flowing through the compressor motor 15 . The power supply device 101 also includes a microcomputer (hereinafter referred to as a microcomputer) 16 that reads the DC voltage Vdc detected by the bus voltage detector 17 and the compressor current detected by the compressor current detector 18, and It has relay drive circuits 19A to 19C driven by signals.

The converter section 13A has reactors La and Lb, relays Ra1, Rb1 and Rc1 which are switching sections, relay excitation coils 8A, 8B and 8C, and smoothing capacitors Ca and Cb. Relay Ra1 is a first switching unit, and relays Rb1 and Rc1 are second switching units.

Reactors La and Lb are reactors with different inductance values. That is, the power supply device 101 has a plurality of reactors with different inductance values. The smoothing capacitors Ca and Cb are capacitors having different capacitor capacities. That is, the power supply device 101 has a plurality of capacitors with different capacitor capacities.

The relay Ra1 is connected to the commercial AC power supply 1. Relay Ra1 switches connection with commercial AC power supply 1 to connection with one of reactors La and Lb connected in parallel. That is, the relay Ra1 switches between the commercial AC power supply 1 and the reactors La and Lb to connect the commercial AC power supply 1 to the reactor La or to the reactor Lb.

Each of the reactors La and Lb has one end connectable to the relay Ra1 and the other end connected to the diode bridge 4 via the connection point 31 . Diode bridge 4 is an example of a rectifier circuit.

The relay excitation coil 8A is connected to the relay drive circuit 19A. The relay excitation coil 8B is connected to the relay drive circuit 19B, and the relay excitation coil 8C is connected to the relay drive circuit 19C.

The relay drive circuit 19A drives the relay Ra1 by controlling the relay excitation coil 8A. The relay drive circuit 19B drives the relay Rb1 by controlling the relay excitation coil 8B. The relay drive circuit 19C drives the relay Rc1 by controlling the relay excitation coil 8C.

The diode bridge 4 is connected to the reactors La and Lb, the commercial AC power supply 1, the relay Rb1, and the connection point 33. The relay Rb1 has one end connected to the diode bridge 4 and the other end connectable to the connection point 34 or the connection point 32 . The relay Rb1 switches connection with the diode bridge 4 to connection with one of the parallel-connected smoothing capacitors Ca and Cb. That is, the relay Rb1 connects the diode bridge 4 to the smoothing capacitor Ca through the connection point 32, or connects the smoothing capacitor Ca through the connection point 34 between the diode bridge 4 and the

connection points

32 and 34. Toggles whether to connect to Cb.

One end of the smoothing capacitor Ca is connectable to the relays Rb1 and Rc1 via the connection point 32, and the other end is connected to the connection point 33. Smoothing capacitor Cb has one end connectable to relays Rb1 and Rc1 via connection point 34 and the other end connected to connection point 35 .

One end of the relay Rc1 is connected to the inverter section 14 via the connection point 36, and the other end is connectable to the connection point 34 or the connection point 32. The relay Rc1 switches connection with the inverter unit 14 to connection with one of the parallel-connected smoothing capacitors Ca and Cb. That is, the relay Rc1 connects the inverter section 14 to the smoothing capacitor Ca via the connection point 32 or connects the smoothing capacitor Ca via the connection point 34 between the inverter section 14 and the

connection points

32 and 34 . Toggles whether to connect to Cb.

The connection point 35 is connected to the connection point 33 and the connection point 37. The inverter unit 14 is connected to the

connection points

36 and 37 and the compressor motor 15 . The compressor current detection unit 18 is connected to the inverter unit 14 and detects the compressor current flowing through the compressor motor 15 by detecting the current flowing through the inverter unit 14 . The bus voltage detection unit 17 is connected to the

connection points

36 and 37 and detects the bus voltage of the inverter unit 14, that is, the DC voltage Vdc.

A microcomputer 16, which is a control device, is connected to relay drive circuits 19A to 19C, a compressor current detector 18, and a bus voltage detector 17. The microcomputer 16 receives the compressor current detected by the compressor current detector 18 and the DC voltage Vdc detected by the bus voltage detector 17 . Microcomputer 16 controls relay drive circuits 19A-19C based on DC voltage Vdc and compressor current.

The microcomputer 16 according to the first embodiment is configured such that one of the reactors La and Lb and one of the smoothing capacitors Ca and Cb is controlled so that the DC voltage Vdc is within the permissible range and the compressor current is within the permissible range. The power supply device 101 is operated with either one.

Note that the switching unit arranged in the power supply device 101 is not limited to the relays Ra1 and Rb1, and any switching unit such as a semiconductor switch may be used as long as it is a device capable of switching connections.

FIG. 2 is a diagram showing the configuration of a microcomputer included in the power supply device according to the first embodiment. The microcomputer 16 has a voltage storage section 22 , a voltage comparison section 23 , a current storage section 25 , a current comparison section 26 and a relay control section 24 . The voltage storage unit 22 is the first storage unit, and the current storage unit 25 is the second storage unit.

The voltage storage unit 22 is connected to the bus voltage detection unit 17 and the voltage comparison unit 23 . Voltage comparator 23 is connected to relay controller 24 and current comparator 26 . Current storage unit 25 is connected to compressor current detection unit 18 and current comparison unit 26 . The relay control section 24 is connected to the current comparing section 26 and the relay driving circuits 19A to 19C.

The voltage storage unit 22 is a memory or the like that stores the DC voltage Vdc detected by the bus voltage detection unit 17, the allowable voltage of the DC voltage Vdc, and the allowable limit voltage of the DC voltage Vdc. The allowable voltage is the voltage allowed for the power supply device 101 , and the allowable limit voltage is the limit voltage allowed for the power supply device 101 . In other words, the allowable voltage is a first reference value of voltage (first voltage reference value), and the allowable limit voltage is a second reference value of voltage (second voltage reference value). Also, the allowable voltage is a value smaller than the allowable limit voltage.

The allowable voltage is obtained by temporarily stopping the operation of the compressor motor 15, that is, the operation of the compressor motor 15 using the converter unit 13A, and switching the reactors La and Lb or switching the smoothing capacitors Ca and Cb. It is a reference value for determining whether or not. The permissible limit voltage is a reference value for determining whether to completely stop the operation of the power supply device 101 and notify the abnormality. Therefore, when the DC voltage Vdc becomes equal to or higher than the allowable voltage, the power supply device 101 can resume operation after the switching of the reactors La and Lb or the switching of the smoothing capacitors Ca and Cb. becomes equal to or higher than the allowable limit voltage, the power supply device 101 stops the operation and notifies the abnormality.

When the DC voltage Vdc is equal to or higher than the allowable voltage, the microcomputer 16 stops the operation of the compressor motor 15 and executes at least one of switching between the reactors La and Lb and switching between the smoothing capacitors Ca and Cb. do. After that, the microcomputer 16 restarts the operation of the compressor motor 15 . When the DC voltage Vdc is equal to or higher than the allowable limit voltage, the microcomputer 16 stops the operation of the compressor motor 15 and notifies the user of the abnormality.

When comparing the DC voltage Vdc and the allowable voltage of the DC voltage Vdc, the voltage comparison unit 23 reads the DC voltage Vdc and the allowable voltage of the DC voltage Vdc from the voltage storage unit 22 . When comparing the DC voltage Vdc with the allowable limit voltage of the DC voltage Vdc, the voltage comparator 23 reads the DC voltage Vdc and the allowable limit voltage of the DC voltage Vdc from the voltage storage unit 22 .

The voltage comparison unit 23 compares the DC voltage Vdc with the allowable voltage of the DC voltage Vdc when the power supply device 101 starts operating or when current normal information (to be described later) is received. Voltage comparison unit 23 compares DC voltage Vdc with the allowable limit voltage of DC voltage Vdc when power supply device 101 starts operating or when current limit normality information, which will be described later, is received.

When the DC voltage Vdc is lower than the allowable voltage, the voltage comparator 23 sends information indicating that the DC voltage Vdc is lower than the allowable voltage (hereinafter referred to as normal voltage information) to the current comparator 26 .

Also, when the DC voltage Vdc is equal to or higher than the allowable voltage, the voltage comparison unit 23 sends information indicating that the DC voltage Vdc is equal to or higher than the allowable voltage (hereinafter referred to as voltage abnormality information) to the relay control unit 24 .

Further, when the DC voltage Vdc is smaller than the allowable limit voltage, the voltage comparator 23 outputs information indicating that the DC voltage Vdc is smaller than the allowable limit voltage (hereinafter referred to as normal voltage limit information) to the current comparator 26 . send to

The current storage unit 25 is a memory or the like that stores the compressor current detected by the compressor current detection unit 18, the allowable current of the compressor current, and the allowable limit current of the compressor current. The allowable current is the current allowed for the power supply device 101 , and the allowable limit current is the limit current allowed for the power supply device 101 . In other words, the permissible current is a first reference value of current (first current reference value), and the permissible limit current is a second reference value of current (second current reference value). Also, the allowable current is a value smaller than the allowable limit current.

The allowable current is a reference value for determining whether to temporarily stop the operation of the compressor motor 15 and switch the reactors La and Lb or the smoothing capacitors Ca and Cb. The permissible limit current is a reference value for determining whether to completely stop the operation of the power supply device 101 and notify the abnormality. Therefore, when the compressor current exceeds the allowable current, the power supply device 101 can resume operation after switching the reactors La and Lb or switching the smoothing capacitors Ca and Cb. becomes equal to or higher than the allowable limit current, the power supply device 101 stops operation and notifies the abnormality.

When the compressor current is equal to or higher than the allowable current, the microcomputer 16 stops the operation of the compressor motor 15 and executes at least one of switching between the reactors La and Lb and switching between the smoothing capacitors Ca and Cb. . After that, the microcomputer 16 restarts the operation of the compressor motor 15 . If the compressor current is equal to or higher than the allowable limit current, the microcomputer 16 stops the operation of the compressor motor 15 and notifies the user of the abnormality.

Upon receiving the normal voltage information from the voltage comparison unit 23, the current comparison unit 26 reads out the compressor current and the allowable current of the compressor current from the current storage unit 25. In this case, the current comparator 26 compares the compressor current and the allowable current.

When the compressor current is smaller than the allowable current, the current comparing unit 26 sends information indicating that the compressor current is smaller than the allowable current (hereinafter referred to as normal current information) to the relay control unit 24 .

When the compressor current is equal to or higher than the allowable current, the current comparator 26 sends information indicating that the compressor current is equal to or higher than the allowable current (hereinafter referred to as current abnormality information) to the relay control unit 24 .

Upon receiving the voltage limit normal information from the voltage comparison unit 23, the current comparison unit 26 reads the compressor current and the allowable limit current of the compressor current from the current storage unit 25. In this case, the current comparator 26 compares the compressor current with the allowable limit current.

When the compressor current is smaller than the allowable limit current, the current comparator 26 sends information indicating that the compressor current is smaller than the allowable limit current (hereinafter referred to as normal current limit information) to the voltage comparator 23. .

The relay control unit 24 controls the relay drive circuits 19A to 19C based on the information sent from the voltage comparison unit 23 and the information sent from the current comparison unit 26. Upon receiving the voltage abnormality information from the voltage comparison unit 23, the relay control unit 24 controls one of the relay drive circuits 19A to 19C. Also, when the relay control unit 24 receives current abnormality information from the current comparison unit 26, it controls any one of the relay drive circuits 19A to 19C.

When the voltage comparison unit 23 determines that the DC voltage Vdc is smaller than the allowable voltage and the current comparison unit 26 determines that the compressor current is smaller than the allowable current, the microcomputer 16 determines that the compressor motor 15 is Continue driving. An element pair that is a combination of a reactor and a smoothing capacitor when the DC voltage Vdc is smaller than the allowable voltage and the compressor current is smaller than the allowable current is allowed and recommended for the operation of the compressor motor 15. It is a combination (permissible combination).

When the voltage comparator 23 determines that the DC voltage Vdc is equal to or higher than the allowable voltage, the microcomputer 16 temporarily stops the operation of the compressor motor 15 and switches the reactors La and Lb or the smoothing capacitors Ca and Cb. , the operation of the compressor motor 15 is restarted.

When the current comparator 26 determines that the compressor current is equal to or higher than the allowable current, the microcomputer 16 temporarily stops the operation of the compressor motor 15 and switches the reactors La and Lb or the smoothing capacitors Ca and Cb. , the operation of the compressor motor 15 is restarted.

Further, when the voltage comparison unit 23 determines that the DC voltage Vdc is equal to or higher than the allowable limit voltage, the microcomputer 16 stops the operation of the compressor motor 15 . Further, the microcomputer 16 stops the operation of the compressor motor 15 when the current comparator 26 determines that the compressor current is equal to or higher than the allowable limit current.

The relationship between the inductance value of the reactor La and the inductance value of the reactor Lb is such that the inductance value of the reactor La<the inductance value of the reactor Lb.

In the power supply device 101, the reactor La is connected between the commercial AC power supply 1 and the diode bridge 4 when the relay excitation coil 8A is not excited by the relay drive circuit 19A. Further, when the relay excitation coil 8A is excited by the relay driving circuit 19A, the commercial AC power supply 1 and the diode bridge 4 are connected by the reactor Lb.

The relationship between the capacitance of the smoothing capacitor Ca and the capacitance of the smoothing capacitor Cb is that the capacitance of the smoothing capacitor Ca<the capacitance of the smoothing capacitor Cb.

When the relay drive circuit 19B does not excite the relay excitation coil 8B and when the relay drive circuit 19C does not excite the relay excitation coil 8C, the diode bridge 4 and the inverter section 14 are connected by the smoothing capacitor Ca. . When the relay drive circuit 19B excites the relay excitation coil 8B and the relay drive circuit 19C excites the relay excitation coil 8C, the diode bridge 4 and the inverter section 14 are connected by the smoothing capacitor Cb. be done.

In this manner, the microcomputer 16 establishes connection between the commercial AC power supply 1 and the diode bridge 4 through either reactor La or Lb depending on whether the relay drive circuit 19A excites the relay excitation coil 8A. It is possible to control whether

In addition, the microcomputer 16 connects between the diode bridge 4 and the inverter unit 14 depending on whether the relay drive circuit 19B excites the relay excitation coil 8B and whether the relay drive circuit 19C excites the relay excitation coil 8C. , smoothing capacitors Ca and Cb to be connected.

Here, the voltages stored in the voltage storage unit 22 will be described. The voltage storage unit 22 stores the voltage of the difference between the maximum value and the minimum value of the DC voltage Vdc detected by the bus voltage detection unit 17 as the DC voltage Vdc detected by the bus voltage detection unit 17 . Further, the voltage storage unit 22 stores the voltage of the difference between the maximum value and the minimum value of the allowable range of the DC voltage Vdc as the allowable voltage, and stores the difference between the maximum value and the minimum value of the allowable limit range of the DC voltage Vdc. is stored as the allowable limit voltage. Thus, the allowable voltage is defined by the maximum and minimum values of the allowable range of the DC voltage Vdc, and the allowable limit voltage is defined by the maximum and minimum values of the allowable limit range of the DC voltage Vdc. there is

The current stored in the current storage unit 25 will be described. The current storage unit 25 stores the maximum value of the compressor current detected by the compressor current detection unit 18 as the compressor current. Further, the current storage unit 25 stores the allowable maximum value of the compressor current as the allowable current, and stores the maximum allowable limit value of the compressor current as the allowable limit current. Thus, the permissible current is defined by the maximum value of the permissible range of compressor current, and the permissible limit current is defined by the maximum value of the permissible limit range of compressor current.

Next, the processing procedure of the first control processing by the power supply device 101 will be described. 3 is a flowchart of a procedure of first control processing by the power supply device according to the first embodiment; FIG. In the first control process, the microcomputer 16 controls the relay drive circuits 19A-19C based on the DC voltage Vdc and the compressor current.

When the power supply device 101 starts the first control process, the bus voltage detector 17 detects the DC voltage Vdc (step ST2). Bus voltage detection unit 17 may always detect DC voltage Vdc during operation of power supply device 101 . The voltage storage unit 22 stores the difference between the maximum value and the minimum value of the DC voltage Vdc detected by the bus voltage detection unit 17 as the DC voltage Vdc.

When the power supply device 101 starts the first control process, the commercial alternating current power supply 1 and the diode bridge 4 are connected by the reactor La, and the diode bridge 4 and the inverter section 14 are connected to each other through smoothing. are connected by a capacitor Ca. The voltage storage unit 22 stores the voltage of the difference between the maximum value and the minimum value of the DC voltage Vdc detected by the bus voltage detection unit 17 as the DC voltage Vdc detected by the bus voltage detection unit 17 .

The voltage comparison unit 23 compares the DC voltage Vdc stored in the voltage storage unit 22 with the allowable voltage stored in the voltage storage unit 22 in advance, and determines whether or not the DC voltage Vdc<allowable voltage ( step ST3).

When the DC voltage Vdc<the allowable voltage (step ST3, Yes), the compressor current detector 18 detects the compressor current (step ST4). Note that the compressor current detection unit 18 may constantly detect the compressor current while the power supply device 101 is in operation. The current storage unit 25 stores the maximum value of the compressor current detected by the compressor current detection unit 18 as the compressor current.

The current comparison unit 26 compares the compressor current stored in the current storage unit 25 with the allowable current stored in advance in the current storage unit 25, and determines whether or not compressor current<allowable current ( step ST5).

If compressor current < allowable current (step ST5, Yes), the power supply device 101 continues the operation of the compressor motor 15 (step ST6). As a result, the power supply device 101 can prevent power supply resonance and operate stably. Then, after the specific time has passed, the power supply device 101 returns to the process of step ST2. That is, the bus voltage detector 17 detects the DC voltage Vdc (step ST2).

If the DC voltage Vdc<the allowable voltage is not satisfied (step ST3, No), the power supply device 101 proceeds to the process of step ST7. Further, when the DC voltage Vdc<the allowable voltage, the power supply device 101 executes the processes of steps ST4 and ST5.

The current comparison unit 26 compares the compressor current stored in the current storage unit 25 with the allowable current stored in advance in the current storage unit 25, and determines whether or not compressor current<allowable current ( step ST5). If compressor current < allowable current (step ST5, No), the power supply device 101 proceeds to the process of step ST7. Moreover, when compressor current < allowable current, the power supply device 101 executes the process of step ST6.

If the DC voltage Vdc < the allowable voltage or the compressor current < the allowable current, the microcomputer 16 determines that there is a power supply resonance abnormality and stops the operation of the compressor motor 15 . That is, the microcomputer 16 stops supplying the DC voltage Vdc from the converter section 13A to the inverter section 14 . Further, the microcomputer 16 drives the relay Ra1 by exciting the relay excitation coil 8A with the relay drive circuit 19A. As a result, the microcomputer 16 switches the connection between the commercial AC power supply 1 and the diode bridge 4 from the reactor La to the reactor Lb, and starts the operation of the compressor motor 15 (step ST7). That is, the microcomputer 16 starts supplying the DC voltage Vdc from the converter section 13A to the inverter section 14 .

After that, the power supply device 101 executes the processing from steps ST8 to ST12. The processing from steps ST8 to ST12 is the same as the processing from steps ST2 to ST6 described above. That is, in step ST8, the bus voltage detection unit 17 detects the DC voltage Vdc, and in step ST9, the voltage comparison unit 23 determines whether or not DC voltage Vdc<allowable voltage. In step ST10, the compressor current detector 18 detects the compressor current, and in step ST11, the current comparator 26 determines whether or not compressor current<allowable current. In step ST12, the power supply device 101 continues the operation of the compressor motor 15, and after the specific time has elapsed, the process returns to step ST8.

If the DC voltage Vdc<allowable voltage is not satisfied (step ST9, No) or if the compressor current<allowable current is not satisfied (step ST11, No), the microcomputer 16 proceeds to the process of step ST13.

If the DC voltage Vdc < the allowable voltage or the compressor current < the allowable current, the microcomputer 16 determines that there is a power supply resonance abnormality and stops the operation of the compressor motor 15 . Further, the microcomputer 16 drives the relay Rb1 by exciting the relay excitation coil 8B with the relay drive circuit 19B. Further, the microcomputer 16 drives the relay Rc1 by exciting the relay excitation coil 8C with the relay driving circuit 19C. As a result, the microcomputer 16 switches the connection between the diode bridge 4 and the inverter section 14 from the smoothing capacitor Ca to the smoothing capacitor Cb, and starts the operation of the compressor motor 15 (step ST13).

After that, the power supply device 101 executes the processes from steps ST14 to ST18. The processing from steps ST14 to ST18 is the same as the processing from steps ST2 to ST6 described above. That is, in step ST14, the bus voltage detection unit 17 detects the DC voltage Vdc, and in step ST15, the voltage comparison unit 23 determines whether DC voltage Vdc<allowable voltage. In step ST16, the compressor current detector 18 detects the compressor current, and in step ST17, the current comparator 26 determines whether or not compressor current<allowable current. In step ST18, the power supply device 101 continues the operation of the compressor motor 15, and after the specific time has elapsed, the process returns to step ST14.

If the DC voltage Vdc < the allowable voltage (step ST15, No) or the compressor current < the allowable current (step ST17, No), the microcomputer 16 proceeds to the process of step ST19.

If the DC voltage Vdc < the allowable voltage or the compressor current < the allowable current, the microcomputer 16 determines that there is a power supply resonance abnormality and stops the operation of the compressor motor 15 . Furthermore, the microcomputer 16 does not excite the relay excitation coil 8A by the relay driving circuit 19A. As a result, the microcomputer 16 switches the connection between the commercial AC power supply 1 and the diode bridge 4 from the reactor Lb to the reactor La to start the operation of the compressor motor 15 (step ST19).

After that, the power supply device 101 executes the processing from steps ST20 to ST24. The processing from steps ST20 to ST24 is the same as the processing from steps ST2 to ST6 described above. That is, in step ST20, the bus voltage detection unit 17 detects the DC voltage Vdc, and in step ST21, the voltage comparison unit 23 determines whether DC voltage Vdc<allowable voltage. In step ST22, the compressor current detector 18 detects the compressor current, and in step ST23, the current comparator 26 determines whether or not compressor current<allowable current. In step ST24, the power supply device 101 continues the operation of the compressor motor 15, and after the specific time has elapsed, the process returns to step ST20.

If DC voltage Vdc<allowable voltage (step ST21, No) or compressor current<allowable current (step ST23, No), the power supply device 101 proceeds to the process of step ST25. The process of step ST25 is the second control process by the power supply device 101 .

By executing the processing from steps ST2 to ST25, the power supply device 101 has executed the following four combinations as element pairs that are combinations of reactors and smoothing capacitors.
・Reactor La and smoothing capacitor Ca
・Reactor La and smoothing capacitor Cb
・Reactor Lb and smoothing capacitor Ca
・Reactor Lb and smoothing capacitor Cb

Note that the power supply device 101 may execute the above four combinations in any order. That is, the power supply device 101 may execute the processes from steps ST2 to ST6, the processes from steps ST7 to ST12, the processes from steps ST13 to ST18, and the processes from steps ST19 to ST24 in any order.

If the microcomputer 16 does not execute the processing of steps ST2 to ST6 first, it executes the same processing as steps ST7, ST13, and ST19 before the processing of step ST2. Specifically, the microcomputer 16, in the processing of steps ST7 to ST12, the processing of steps ST13 to ST18, or the processing of steps ST19 to ST24, when the DC voltage Vdc<the allowable voltage or when the compressor current<the allowable current is not , the operation of the compressor motor 15 is stopped. Further, the microcomputer 16 does not excite the relay excitation coil 8A by the relay drive circuit 19A and does not excite the relay excitation coils 8B and 8C by the

relay drive circuits

19B and 19C. As a result, the microcomputer 16 uses the connection between the commercial AC power supply 1 and the diode bridge 4 as the reactor La, and the connection between the diode bridge 4 and the inverter section 14 as the smoothing capacitor Ca. to start driving.

Next, the processing procedure of the second control processing by the power supply device 101 will be described. 4 is a flowchart of a second control process performed by the power supply according to the first embodiment; FIG. In the second control process, the microcomputer 16 controls the relay drive circuits 19A-19C based on the DC voltage Vdc and the compressor current.

When the first control process ends, the power supply device 101 starts the second control process, which is the process of step ST25. When the power supply device 101 starts the second control process, the microcomputer 16 determines that there is power resonance abnormality and stops the operation of the compressor motor 15 (step ST26).

Furthermore, the microcomputer 16 drives the relay so that the DC voltage Vdc and the compressor current are the combination closest to the allowable voltage and allowable current among the four combinations (four element pairs) described above up to this point. The circuits 19A to 19C are controlled to start operation (step ST27).

That is, the microcomputer 16 sets the element pair, which is the combination of the reactor connected to the commercial AC power supply 1 and the smoothing capacitor connected to the diode bridge 4 and the inverter unit 14, to the combination closest to the allowable voltage and allowable current. The relay driving circuits 19A to 19C are controlled to start operation. In other words, the microcomputer 16 controls the relay drive circuits 19A to 19C so that the combination of the reactor and the smoothing capacitor is such that the DC voltage Vdc is the lowest and the compressor current is the lowest. Start. In this case, microcomputer 16 selects the closest combination of allowable voltage and allowable current based on DC voltage Vdc, allowable voltage, compressor current and allowable current stored in voltage storage unit 22 . The combination of the reactor and the smoothing capacitor closest to the permissible voltage and permissible current is the most stable combination of the DC voltage Vdc and the compressor current.

For example, the microcomputer 16 selects the combination of the reactor La and the smoothing capacitor Ca when the combination of the reactor La and the smoothing capacitor Ca is the combination closest to the allowable voltage and allowable current. Then, the microcomputer 16 controls the relay driving circuit 19A so that the connection between the commercial AC power supply 1 and the diode bridge 4 is connected via the reactor La. Further, the microcomputer 16 controls the

relay drive circuits

19B and 19C so that the connection between the diode bridge 4 and the inverter section 14 is via the smoothing capacitor Ca.

When the power supply device 101 starts operating the compressor motor 15, the bus voltage detection unit 17 detects the DC voltage Vdc (step ST28). The voltage storage unit 22 stores the voltage of the difference between the maximum value and the minimum value of the DC voltage Vdc detected by the bus voltage detection unit 17 as the DC voltage Vdc detected by the bus voltage detection unit 17 .

The voltage comparison unit 23 compares the DC voltage Vdc stored in the voltage storage unit 22 with the permissible limit voltage previously stored in the voltage storage unit 22, and determines whether or not the DC voltage Vdc<the permissible limit voltage. (step ST29).

If the DC voltage Vdc<the allowable limit voltage is not satisfied (step ST29, No), the power supply device 101 proceeds to the process of step ST35. If the DC voltage Vdc<the allowable limit voltage (step ST29, Yes), the compressor current detector 18 detects the compressor current (step ST30). The current storage unit 25 stores the maximum value of the compressor current detected by the compressor current detection unit 18 as the compressor current.

The current comparison unit 26 compares the compressor current stored in the current storage unit 25 with the permissible limit current stored in advance in the current storage unit 25, and determines whether or not compressor current<permissible limit current. (step ST31).

If compressor current < allowable current (step ST31, No), the power supply device 101 proceeds to the process of step ST35. If the compressor current<the allowable limit current (step ST31, Yes), the power supply device 101 continues the operation of the compressor motor 15 (step ST32). As a result, the power supply device 101 can be operated within a range in which there is no problem in quality even in a state of being subjected to power supply resonance.

The microcomputer 16 determines whether or not the elapsed operation time, which is the elapsed time since the power supply device 101 started operating the compressor motor 15 in the second control process, has passed a specific time. That is, the microcomputer 16 determines whether or not elapsed driving time>specific time (step ST33).

If the elapsed operation time>the specific time is not satisfied (step ST33, No), the power supply device 101 returns to the process of step ST28. On the other hand, if the elapsed operation time>the specific time (step ST33, Yes), the power supply device 101 returns to the first control process (step ST34). That is, the process returns to step ST2 in FIG.

If the DC voltage Vdc < the allowable limit voltage (step ST29, No) or if the compressor current <the allowable limit current (step ST31, No), the microcomputer 16 determines that there is a power supply resonance abnormality, and determines that the compressor motor 15 is stopped and an abnormality is notified (step ST35). That is, the microcomputer 16 determines that the DC voltage Vdc or the compressor current exceeds the permissible limit and that there is a power supply resonance abnormality, stops the operation of the compressor motor 15, and notifies the user of the abnormality.

The power supply device 101 can change at least one of the reactor and the smoothing capacitor according to the magnitude of the load on the inverter section 14 . As a result, the power supply device 101 can change the DC voltage Vdc to be generated, so that the DC voltage Vdc can be changed according to the characteristics or operating range of the compressor motor 15 . Therefore, since the power supply device 101 is not affected by the operating frequency of the compressor motor 15 and the characteristics of the compressor motor 15, no distortion occurs in the DC voltage Vdc. As a result, the power supply device 101 can prevent the occurrence of power resonance due to the characteristics of the power supply device 101 and the compressor motor 15 and the environment in which they are used. can.

Moreover, since the power supply device 101 can change at least one of the reactor and the smoothing capacitor, even if the characteristics of the compressor motor 15 are changed or the operating frequency of the compressor motor 15 is changed, , the current flowing through the compressor motor 15 is not distorted due to the wiring environment. Therefore, regardless of the characteristics of the power supply device 101 and the compressor motor 15 and the operating environment, the power supply resonance of the DC voltage Vdc and the compressor current does not occur in the power supply device 101 . Therefore, the operation of the power supply device 101 does not become unstable, the maximum value of the compressor current does not reach the upper limit of the protection circuit, and the operation of the compressor motor 15 does not stop.

Thus, in Embodiment 1, the voltage comparator 23 compares the DC voltage Vdc and the allowable voltage, and the current comparator 26 compares the compressor current and the allowable current. Also, the voltage comparator 23 compares the DC voltage Vdc with the permissible limit voltage, and the current comparator 26 compares the compressor current with the permissible limit current. Then, the microcomputer 16 controls the relay drive circuits 19A to 19C based on these comparison results to use a combination of either the reactor La or Lb and the smoothing capacitor Ca or Cb to perform compression. The machine motor 15 is running.

As a result, the power supply device 101 can operate the compressor motor 15 and the air conditioner while preventing power supply resonance due to the characteristics and usage environment of the power supply device 101 and the compressor motor 15 . Further, the power supply device 101 can prevent power supply resonance and achieve power saving.

Also, the power supply device 101 selects an appropriate combination of one of the reactors La and Lb and one of the smoothing capacitors Ca and Cb based on the DC voltage Vdc and the compressor current. As a result, the power supply device 101 can improve the power factor of the air conditioner and efficiently operate the air conditioner.

Embodiment 2.
Next, Embodiment 2 will be described with reference to FIGS. 5 and 6. FIG. In the second embodiment, the three reactors are switched and the three smoothing capacitors are switched according to the values of the DC voltage Vdc and the compressor current.

FIG. 5 is a diagram showing the configuration of the power supply device according to the second embodiment. 5 that achieve the same functions as those of the power supply device 101 of Embodiment 1 shown in FIG. 1 are denoted by the same reference numerals, and overlapping descriptions are omitted.

The power supply device 102, like the power supply device 101, drives the compressor motor 15 by means of the inverter section 14. Power supply device 102 includes converter section 13B instead of converter section 13A, as compared with power supply device 101 .

Compared to the converter section 13A, the converter section 13B has relays Ra2, Rb2, and Rc2 instead of the relays Ra1, Rb1, and Rc1. Further, the converter section 13B has a reactor Lc in addition to the reactors La and Lb as compared with the converter section 13A. In addition to the smoothing capacitors Ca and Cb, the converter unit 13B has a smoothing capacitor Cc as compared with the converter unit 13A.

The relay Ra2 is connected to the commercial AC power supply 1. Also, the relay Ra2 switches the connection with the commercial AC power supply 1 to one of the parallel-connected reactors La to Lc. That is, the relay Ra2 switches between the commercial AC power supply 1 and the reactors La to Lc to connect the commercial AC power supply 1 to the reactor La, to the reactor Lb, or to the reactor Lc.

Each of the reactors La to Lc has one end connectable to the relay Ra2 and the other end connected to the diode bridge 4 via the connection point 31 .

In the second embodiment, the relay drive circuit 19A drives the relay Ra2 by controlling the relay excitation coil 8A. The relay drive circuit 19B drives the relay Rb2 by controlling the relay excitation coil 8B. The relay drive circuit 19C drives the relay Rc2 by controlling the relay excitation coil 8C.

The diode bridge 4 is connected to the reactors La to Lc, the commercial AC power supply 1, the relay Rb2, and the connection point 33. One end of the relay Rb2 is connected to the diode bridge 4, and the other end is connectable to any one of the connection points 34, 32, and 38. As shown in FIG.

One end of the smoothing capacitor Cc is connectable to the relays Rb2 and Rc2 via the connection point 38, and the other end is connected to the connection point 39. Connection point 35 is connected to connection point 37 via connection point 39 .

The relay Rb2 switches connection with the diode bridge 4 to connection with one of the parallel-connected smoothing capacitors Ca to Cc. That is, the relay Rb2 connects the diode bridge 4 to the smoothing capacitor Ca via the connection point 32, to the smoothing capacitor Cb via the connection point 34, or to the smoothing capacitor Cb via the connection point 38. Toggles whether to connect to Cc.

One end of the relay Rc2 is connected to the inverter section 14 via the connection point 36, and the other end is connectable to any one of the connection points 34, 32, and 38. The relay Rc2 switches connection with the inverter unit 14 to connection with one of the parallel-connected smoothing capacitors Ca to Cc. That is, the relay Rc2 connects the inverter section 14 to the smoothing capacitor Ca via the connection point 32, to the smoothing capacitor Cb via the connection point 34, or to the smoothing capacitor Cb via the connection point 38. Toggles whether to connect to Cc.

It should be noted that the switching unit arranged in the power supply device 102 is not limited to the relays Ra2 to Rc2, and any switching unit such as a semiconductor switch may be used as long as it can switch the connection.

Next, the processing procedure of the third control processing by the power supply device 102 will be described. In the third control process, the microcomputer 16 controls the relay drive circuits 19A-19C based on the DC voltage Vdc and the compressor current.

The power supply device 102 has a configuration in which a reactor Lc and a smoothing capacitor Cc are added to the power supply device 101 . Therefore, the number of combinations of reactors and smoothing capacitors increases by the amount of added reactors Lc and smoothing capacitors Cc. That is, in the first embodiment, there are four combinations of reactors and smoothing capacitors, whereas in the second embodiment, there are nine combinations (three types x three types) of reactors and smoothing capacitors. )become.

The power supply device 102 of the second embodiment performs the following five combinations in addition to the four combinations of the first embodiment.
・Reactor La and smoothing capacitor Cc
・Reactor Lb and smoothing capacitor Cc
・Reactor Lc and smoothing capacitor Ca
・Reactor Lc and smoothing capacitor Cb
・Reactor Lc and smoothing capacitor Cc

The power supply device 101 of the first embodiment repeats the same processing as steps ST2 to ST6 four times, but the power supply device 102 of the second embodiment repeats the same processing as steps ST2 to ST6 nine times. repeat. Thereby, the power supply device 102 implements nine combinations of reactors and smoothing capacitors.

The microcomputer 16 of the second embodiment executes the above-described five combinations after executing the four combinations by executing steps ST1 to ST24, which are the first control processing described with reference to FIG.

FIG. 6 is a flow chart showing the procedure of the third control process by the power supply device according to the second embodiment. The microcomputer 16 controls at least one of the relay drive circuits 19A to 19C while the operation of the power supply 102 is stopped, thereby switching the combination of the reactor and the smoothing capacitor to start the operation of the power supply 102. (step ST37). In this case, the microcomputer 16 switches to an unexecuted combination among the combinations of the reactor and the smoothing capacitor.

After that, the power supply device 102 executes the processing from steps ST38 to ST42. The processing from steps ST38 to ST42 is the same as the processing from steps ST2 to ST6 described above. That is, in step ST38, the bus voltage detection unit 17 detects the DC voltage Vdc, and in step ST39, the voltage comparison unit 23 determines whether or not DC voltage Vdc<allowable voltage. In step ST40, the compressor current detector 18 detects the compressor current, and in step ST41, the current comparator 26 determines whether or not compressor current<allowable current. In step ST42, the power supply device 102 continues the operation of the compressor motor 15, and after the specific time has elapsed, the process returns to step ST38.

If the DC voltage Vdc < the allowable voltage (step ST39, No) or the compressor current < the allowable current (step ST41, No), the microcomputer 16 proceeds to the process of step ST43.

The microcomputer 16 determines whether or not the switching process has been executed a specified number of times (step ST43). The prescribed number of times is the number of times of switching that can execute all the combinations of the reactor and the smoothing capacitor. In the second embodiment, the number of combinations of reactors and smoothing capacitors is nine, so the microcomputer 16 determines whether switching processing has been performed eight times.

If the microcomputer 16 has not executed the switching process for the prescribed number of times (step ST43, No), it executes the process from step ST37 to ST43. Note that the power supply device 102 may execute the above nine combinations in any order.

When the third control process ends, that is, when the switching process has been performed the specified number of times (step ST43, Yes), the power supply 102 starts the second control process, which is the process of step ST25.

As described in the first and second embodiments, the number of reactors and smoothing capacitors included in

power supply devices

101 and 102 with variable reactors and smoothing capacitors is limited to two types each or three types each. do not have. There is no limit to the number of reactors and smoothing capacitors that

power supply devices

101 and 102 have, as long as at least one of the reactors and smoothing capacitors is plural.

As described above, in the second embodiment, the microcomputer 16 controls the relay drive circuits 19A to 19C to use a combination of any one of the reactors La to Lc and any one of the smoothing capacitors Ca to Cc. I am driving a 102. Therefore, in the second embodiment as well, the same effect as in the first embodiment can be obtained. That is, the power supply 102 can prevent power supply resonance due to the characteristics of the power supply 102 and the compressor motor 15 and the usage environment, and can operate the air conditioner while preventing the power supply resonance.

Since the power supply device 102 has more reactors and smoothing capacitors to choose from than the power supply device 101, the air conditioner can be operated more stably than the power supply device 101.

Here, the hardware configuration of the microcomputer 16 will be explained. The microcomputer 16 is implemented by a processing circuit. The processing circuitry may be a processor and memory executing programs stored in the memory, or may be dedicated hardware.

FIG. 7 is a diagram showing a configuration example of a processing circuit when the processing circuit provided in the microcomputer according to the first and second embodiments is realized by a processor and memory. A processing circuit 90 shown in FIG. 7 includes a processor 91 and a memory 92 . When the processing circuit 90 is composed of the processor 91 and the memory 92, each function of the processing circuit 90 is implemented by software, firmware, or a combination of software and firmware. Software or firmware is written as a program and stored in memory 92 . In the processing circuit 90, each function is realized by the processor 91 reading and executing the program stored in the memory 92. FIG. That is, the processing circuit 90 has a memory 92 for storing a program that results in the execution of the processing of the microcomputer 16 . This program can also be said to be a program for causing the microcomputer 16 to execute each function realized by the processing circuit 90 . This program may be provided by a storage medium storing the program, or may be provided by other means such as a communication medium. The above program can also be said to be a program that causes the microcomputer 16 to execute the processes described with reference to FIGS.

Here, the processor 91 is, for example, a CPU (Central Processing Unit), a processing device, an arithmetic device, a microprocessor, a microcontroller, or a DSP (Digital Signal Processor). In addition, the memory 92 is a non-volatile or volatile memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), EEPROM (registered trademark) (Electrically EPROM), etc. A semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, or a DVD (Digital Versatile Disc) is applicable.

FIG. 8 is a diagram showing an example of a processing circuit when the processing circuit included in the microcomputer according to the first and second embodiments is configured with dedicated hardware. The processing circuit 93 shown in FIG. 8 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these thing applies. The processing circuit 93 may be partially realized by dedicated hardware and partially realized by software or firmware. Thus, the processing circuitry 93 can implement each of the functions described above by dedicated hardware, software, firmware, or a combination thereof.

The configurations shown in the above embodiments are only examples, and can be combined with other known techniques, or can be combined with other embodiments, without departing from the scope of the invention. It is also possible to omit or change part of the configuration.

1 Commercial AC power supply, 4 Diode bridge, 8A to 8C Relay excitation coil, 13A, 13B Converter section, 14 Inverter section, 15 Compressor motor, 16 Microcomputer, 17 Bus voltage detection section, 18 Compressor current detection section, 19A ~ 19C relay drive circuit, 22 voltage storage unit, 23 voltage comparison unit, 24 relay control unit, 25 current storage unit, 26 current comparison unit, 31 to 39 connection points, 90, 93 processing circuit, 91 processor, 92 memory, 101, 102 Power supply, Ca-Cc smoothing capacitor, La-Lc reactor, Ra1-Rc1, Ra2-Rc2 relay.

Claims

a converter unit that converts the AC voltage of a commercial AC power supply to a DC voltage;
an inverter unit that converts the DC voltage from the converter unit into an AC voltage to drive the motor;
a voltage detection unit that detects the voltage value of the DC voltage supplied to the inverter unit;
a current detection unit that detects a current value flowing through the motor;
a control device that controls the converter;
with
The converter section
a plurality of reactors connectable to the commercial AC power supply and having different inductance values;
a rectifier circuit connected to the commercial AC power supply via one of the plurality of reactors and rectifying an AC voltage from the commercial AC power supply to generate the DC voltage;
a plurality of smoothing capacitors having different capacitor capacities connectable to the rectifier circuit and the inverter unit, and smoothing the DC voltage while being connected to the rectifier circuit and the inverter unit and sending the DC voltage to the inverter unit;
a first switching unit that switches which one of the plurality of reactors is to be connected to the commercial AC power supply;
a second switching unit that switches which of the plurality of smoothing capacitors is connected to the rectifier circuit and the inverter;
has
The control device is
A power supply device that controls the first switching section and the second switching section based on the voltage value detected by the voltage detection section and the current value detected by the current detection section.
The control device is
a first storage unit that stores a first voltage reference value that is a first reference value for the voltage value;
a voltage comparison unit that compares the voltage value detected by the voltage detection unit and the first voltage reference value;
a relay control unit that controls the first switching unit and the second switching unit based on the comparison result of the voltage comparison unit;
having
The power supply device according to claim 1 .
The control device is
a second storage unit that stores a first current reference value that is a first reference value for the current value;
a current comparison unit that compares the current value detected by the current detection unit and the first current reference value;
has
The relay control unit controls the first switching unit and the second switching unit based on the comparison result of the current comparison unit.
The power supply device according to claim 2.
The control device is
The element pair, which is a combination of the reactor connected to the commercial AC power supply and the smoothing capacitor connected to the rectifier circuit and the inverter unit, has a voltage value lower than the first voltage reference value. and controlling the first switching unit and the second switching unit so that an allowable combination is a combination in which the current value is lower than the first current reference value,
The power supply device according to claim 3.
The control device is
If the element pair is not the allowable combination, supply of the DC voltage from the converter section to the inverter section is stopped, and the element pair is changed to supply the DC voltage from the converter section to the inverter section. to start the
The power supply device according to claim 4.
The control device is
If all of the element pairs are not the allowable combination, the element pair is the combination in which the voltage value is closest to the first voltage reference value and the current value is closest to the first current reference value. controlling the first switching unit and the second switching unit so that
The power supply device according to claim 4 or 5.
The control device is
The voltage value detected by the voltage detection unit is compared with a second voltage reference value that is greater than the first voltage reference value and is a second reference value for the voltage value, and the voltage detection unit detects stopping the supply of the DC voltage from the converter unit to the inverter unit when the voltage value obtained is equal to or higher than the second voltage reference value;
The power supply device according to any one of claims 2 to 6.
The control device is
The current value detected by the current detection unit is compared with a second current reference value that is larger than the first current reference value and is a second reference value for the current value, and the current detection unit detects stopping the supply of the DC voltage from the converter unit to the inverter unit when the current value obtained is equal to or greater than the second current reference value;
The power supply device according to any one of claims 3 to 6.
The first switching unit and the second switching unit are relays,
The power supply device according to any one of claims 1 to 8.