JP2023070943A - Power source system and power supply control device - Google Patents

Abstract

To generate a three-phase AC using a plurality of external power supplies each outputting a single-phase AC, while ensuring protection performance against load.SOLUTION: Provided is a power source system including: a first external power supply, a second external power supply, and a third external power supply which are connected to a vehicle battery and convert DC power stored in the battery into single-phase AC power; and a power supply control device which generates and outputs a three-phase AC signal that is obtained by synchronizing, with 120° phase difference, single-phase AC signals output from the first external power supply, the second external power supply, and the third external power supply. The power supply control device includes monitoring means for monitoring the three-phase AC signal generated by the power supply control device and regulating means for regulating the output of the three-phase AC signal if an abnormality is detected in the three-phase AC signal by the monitoring means.SELECTED DRAWING: Figure 3

Description

The present invention relates to a power supply system and a power supply control device.

Patent Literature 1 discloses a configuration of a power converter that converts supplied DC power into single-phase AC power by a DC/AC conversion circuit and outputs the converted AC power. In addition, as vehicles become increasingly electrified, a portable external power supply device that is mounted on a vehicle and externally supplies electric power from a battery for running the vehicle is becoming popular. Such an external power supply can normally supply power to loads such as electrical products, and in times of disaster when the grid power cannot be used, it can supply power to a relief base such as an evacuation center. It is possible to In this way, the field of activity that requires an external power supply is expanding.

JP 2016-208635 A

However, portable external power feeders are designed to output single-phase AC power. may not be able to supply It would be very convenient if the external power feeder could be used as a three-phase AC power source. In that case, it is desirable to ensure the protection performance of the load that receives power supply.

SUMMARY OF THE INVENTION An object of the present invention is to provide a technique for generating three-phase AC signals using a plurality of external power feeders that output single-phase AC signals while ensuring load protection performance.

According to the invention,
a first external power feeder, a second external power feeder, and a third external power feeder, which are connected to a vehicle battery and convert DC power stored in the battery into single-phase AC power;
A three-phase AC signal is generated and output by synchronizing the single-phase AC signals output from the first external power feeder, the second external power feeder, and the third external power feeder with a phase difference of 120°. a power supply control device that
A power system comprising:
The power supply control device,
monitoring means for monitoring the three-phase AC signal generated by the power supply control device;
a regulating means for regulating the output of the three-phase AC signal when the monitoring means detects that the three-phase AC signal has an abnormality;
There is provided a power supply system characterized by:

According to the present invention, it is possible to provide a technique of generating a three-phase AC signal using a plurality of external power feeders that output a single-phase AC signal while ensuring protection performance for a load.

The figure which shows the structure of the power supply system which concerns on one Embodiment. The figure which shows the structure of an external electric power feeder. The figure which shows the structure of a power supply control apparatus. FIG. 4 is a diagram for explaining processing of a phase synchronization unit; (A) is a comparison diagram of power during normal operation and phase failure, and (B) is a diagram showing an example of a negative phase monitoring circuit. The figure which shows another structural example of an electric power feeding control apparatus.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined arbitrarily. Also, the same or similar configurations are denoted by the same reference numerals, and redundant explanations are omitted.

<First Embodiment>
<Summary of power supply system>
FIG. 1 is a diagram showing the configuration of a power supply system 10 according to one embodiment of the present invention. The power supply system 10 has external power feeders 20A to 20C and a power feed control device 30 .

The external power feeders 20A to 20C are connected to the battery BT of the corresponding vehicle VEH, convert the DC power stored in the battery BT into single-phase AC power, and output the single-phase AC power. Battery BT is, for example, a lithium ion battery. The vehicle VEH is, for example, an electric vehicle (EV), a plug-in hybrid vehicle (PHEV), or a fuel cell vehicle (FCV vehicle) that drives a motor generator with electric power stored in a battery BT and runs with the driving force of the motor generator. ). The external power feeders 20A to 20C are connected to the power feed control device 30 via the cable 3. FIG.

The external power feeders 20A to 20C are each connected to the vehicle VEH via a connector 60 of a predetermined connection standard, and are stored in the battery BT of the vehicle VEH and convert the output DC power into single-phase AC power. Output. As the connector 60, a connector conforming to the ChadeMO standard, which is a rapid charging standard, can be used. However, the connection standard of the connector 60 is not limited to this example, and connectors of various connection standards can be used. .

The power supply control device 30 generates a three-phase AC signal by synchronizing the single-phase AC signals output from the external power feeders 20A to 20C with a phase difference of 120°, and supplies the three-phase AC signal to the load.

<Configuration of external power supply>
In this embodiment, the external power feeders 20B and 20C have the same configuration as the external power feeder 20A, so the configuration of the external power feeder 20A will be described as a representative. FIG. 2 is a diagram showing the configuration of the external power feeder 20A.

The external power feeder 20A is connected to an interface section 21 that can be connected to the vehicle VEH via a connector 60, an inverter unit 22 that converts DC power from the vehicle VEH into single-phase AC power and outputs the same, and a filter section 24. 26.

The inverter unit 22 has three inverter circuits 22a to 22c. Each of the inverter circuits 22a to 22c converts the DC signal input from the interface unit 21 into a single-phase AC signal of a predetermined frequency (commercial frequency of 50 Hz or 60 Hz, for example). Each of the inverter circuits 22a to 22c is configured as, for example, an H bridge circuit, and includes a plurality of switching elements composed of transistors such as MOSFETs and IGBTs, and diodes (parasitic diodes) connected in parallel to each switching element. may also be used). Each switching element is turned on and off by a control signal output from the control circuit 23, thereby converting the DC signal into a single-phase AC signal.

The inverter unit 22 also has voltage/current sensors S1 and S2 and a control circuit 23 that controls the inverter circuits 22a to 22c. The voltage/current sensor S1 is a sensor that detects the voltage and current on the power line L1 at the connection terminal 26a, and can detect the AC voltage and AC current output from the inverter circuit 22a. The voltage/current sensor S2 is a sensor that detects the voltage and current on the power line L2 at the connection terminal 26a, and can detect the AC voltage and AC current output from the inverter circuit 22b.

Based on the detection results of the voltage/current sensors S1 and S2, the control circuit 23 manages the operating states of the inverter circuits 22a and 22b. The control circuit 23 is configured by a microcomputer including a processor such as a CPU and storage devices such as a ROM and a RAM.

The inverter unit 22 is connected to the filter section 24 . The filter unit 24 includes an LC filter 24a (low-pass filter) for removing harmonic components and a noise filter 24b for removing noise. Each AC signal output from the inverter circuits 22a to 22c is input to an LC filter 24a and a noise filter 24b to remove harmonic components and noise.

The filter section 24 is connected to the connection section 26 . The connection unit 26 has connection terminals 26 a to 26 c that can be connected to the power supply control device 30 or the load 50 . In the connection example shown in FIG. 2, the inverter circuit 22a and the inverter circuit 22b are connected to the power supply control device 30 via the connection terminals 26a and 26b, respectively, and the inverter circuit 22c is connected to the load 50 via the connection terminal 26c. there is

A cable 3 connecting the external power feeder 20A and the power feed control device 30 includes power lines L1 and L2. The power lines L1 and L2 are power lines through which single-phase AC power is output from the first inverter circuit 22a and the second inverter circuit 22b. In addition, the output single-phase AC power output from the inverter circuit 22c is supplied to the load 50 via the power line L3.

The operation unit 40 is a user interface (UI) between the external power feeder 20A and the user. The operation unit 40 has a connection interface (connection I/F) 41 . The connection interface 41 is a remote controller (not shown) that the user can carry around and a wireless or wired interface, and the user can also instruct the external power supply 40A from the remote controller in place of the operation switch 42 and the mode setting switch 43, which will be described later. It is possible.

The operation unit 40 also includes an operation switch 42 (operation SW) for instructing operation (start)/stop of the external power supply 20A, and a mode setting switch (mode setting SW) for instructing switching of the operation mode of the external power supply 20A. 43. A mode setting switch 43 can be used to set the operation mode of the external power feeder 20A.

The inverter circuits 22a and 22b are connected to a phase adjustment circuit 29 that adjusts the phase difference between the AC voltages they output. The control circuit 23 switches the setting of the phase adjustment circuit 29 based on the operation mode set by the instruction of the mode setting switch 43 .

When a predetermined operation mode (called a three-phase mode) is selected, the control circuit 23 controls the single-phase AC voltage output from the inverter circuit 22b with respect to the single-phase AC voltage output from the inverter circuit 22a. is set to 120°. A single-phase AC signal having a voltage phase difference of 120° is output from power lines L1 and L2. For example, the voltage of the single-phase AC signal output from the power line L1 is represented by A·sin(ωt), and the voltage of the single-phase AC signal output from the power line L2 is A·sin(ωt−2π/3). is represented by A indicates the voltage amplitude and ω indicates the angular frequency. In the above description, the configuration of the external power feeder 20A has been described as a representative example, but the same applies to the external power feeder 20B and the external power feeder 20C. Then, a single-phase AC signal having a voltage phase difference of 120° is output from the power lines L1 and L2. The voltage amplitudes of the single-phase AC signals output from the external power feeders 20A-20C are the same.

<Power supply control device>
FIG. 3 is a diagram showing the configuration of the power supply control device 30. As shown in FIG. The power supply control device 30 has an interface section 31 (I/F section), a control circuit 32, phase synchronization sections 33 and 34, and a generation section 35 as an internal configuration. The interface unit 31 (I/F unit) is an interface connectable to the external power feeder 20A, the external power feeder 20B, and the external power feeder 20C. The I/F unit 31 has a connector 31a to which the cable 3 (including power lines L1 and L2) of the external power feeder 20A is detachably connected, and the cable 3 (including power lines L1 and L2) of the external power feeder 20B is detachably attached. and a connector 31c to which the cable 3 (including the power lines L1 and L2) of the external power feeder 20C is detachably connected.

The control circuit 32 is composed of a microcomputer including a processor such as a CPU and storage devices such as a ROM and a RAM, and controls operations of the phase synchronization units 33 and 34 .

The phase synchronization section 33 and the phase synchronization section 34 include, for example, a PLL circuit (PLL: Phase-locked loop). Functions of the phase synchronization section 33 and the phase synchronization section 34 will be described with reference to FIG. Here, the single-phase AC signals output from the power lines L1 and L2 of the external power feeder 20A are expressed as U1 and V1. Single-phase AC signals output from power lines L1 and L2 of the external power feeder 20B are denoted by V2 and W1. W2 and U2 represent single-phase AC signals output from the power lines L1 and L2 of the external power feeder 20C. When the external power feeders 20A to 20C are operated in the three-phase mode, the voltages of the single-phase AC signal U1 and the single-phase AC signal V1 have a phase difference of 120°, and the single-phase AC signal V2 and the single-phase AC signal W1 have a phase difference of 120°, and the voltages of the single-phase AC signal W2 and the single-phase AC signal U2 have a phase difference of 120°.

The phase synchronization unit 33 adjusts the phase difference α between the single-phase AC signal V2 and the single-phase AC signal V1 to 0 while maintaining the phase difference (120°) between the single-phase AC signal V2 and the single-phase AC signal W1. A single-phase AC signal V2' and a single-phase AC signal W1' obtained by correcting the single-phase AC signal V2 and the single-phase AC signal W1 are output. The phase synchronization unit 34 maintains the phase difference (120°) between the single-phase AC signal W2 and the single-phase AC signal U2, and the phase difference β between the single-phase AC signal W1′ and the single-phase AC signal W2 becomes 0. A single-phase AC signal W2' and a single-phase AC signal U2' obtained by correcting the single-phase AC signal W2 and the single-phase AC signal U2 are output as follows.

The generator 35 generates three-phase AC signals U to W having a voltage phase difference of 120 degrees. The three-phase AC signals U to W are supplied to the load through the cable 4 connecting the power supply controller 30 and the load. The U-phase AC signal is generated from single-phase AC signals U1 and U2', which are voltage synchronization signals. The V-phase AC signal is generated from single-phase AC signals V1 and V2', which are voltage synchronization signals. The W-phase AC signal is generated from single-phase AC signals W1 and W1', which are voltage synchronization signals.

<Monitoring circuit and regulation circuit>
If there is an abnormality in the three-phase AC signals (U to W) output by the power supply control device 30, the performance of the load receiving power may be degraded. It is desirable to ensure the protection performance of the load to which power is supplied. Modes of abnormality in the three-phase AC signals (U to W) include, for example, phase loss and reverse phase. Causes of phase loss and reverse phase include, for example, connection failure between any of the external power feeders 20A to 20C and the power supply control device 30, failure of any of the external power feeders 20A to 20C, and connection of the external power feeders 20A to 20C. power shortage of the battery BT of any one of the three vehicles VEH.

The power supply control device 30 of this embodiment includes a monitoring circuit 36 and a regulation circuit 37 . A monitor circuit 36 monitors the three-phase AC signals (U to W) output from the generator 35 . The regulation circuit 37 regulates the output of the three-phase AC signal when the monitoring circuit 36 detects that there is an abnormality in the three-phase AC signal. In the case of this embodiment, the regulation circuit 37 is a breaker, which cuts off the electrical connection between the power supply control device 30 and the load in the event of an abnormality, thereby stopping the supply of the three-phase AC signal to the load.

A monitoring circuit 36 determines whether there is an abnormality in the three-phase AC signals (U to W) based on the detection results of the sensors 36u to 36w. The sensor 36u corresponds to the U phase, the sensor 36v corresponds to the V phase, and the sensor 36w corresponds to the W phase, and is a sensor for detecting voltage or current or voltage and current of each phase.

The monitoring circuit 36 includes a microcomputer having a processing section 36a, a storage section 36b and an interface section (I/F section) 36c. The processing unit 36a is a processor represented by a CPU, and executes programs stored in the storage unit 36b. The storage unit 36b is a semiconductor memory such as RAM and ROM, or a storage device such as a hard disk, and stores programs executed by the processing unit 36a and various data. The storage unit 36b may include multiple storage devices. The I/F unit 36c is an interface that relays signal transmission/reception between the external device and the processing unit 36a.

The processing unit 36a periodically acquires the detection results of the sensors 36u to 36w and determines whether or not there is an abnormality. For example, if no voltage is detected from the sensor 36u for a predetermined period of time, it is determined that the U phase is open. The same applies to the V phase and W phase.

Further, for example, from the voltage and current detected by the sensors 36u to 36w, the total power of each power of the U-phase, V-phase, and W-phase is calculated. As indicated by P1 in FIG. 5A, if the total power is constant (for example, within a predetermined range) for a predetermined period, it is determined to be normal, and the total power pulsates as indicated by P2. If it is present (if it pulsates out of the predetermined range), it is determined that one of the phases is open.

Also, based on the voltage detection results of the sensors 36u to 36w, the transition of voltage changes in the U-phase, V-phase, and W-phase during a predetermined period is monitored. It is determined that the phase is reversed.

When the processing unit 36a determines that there is an abnormality in the three-phase AC signals (U to W), the processing unit 36a sends a control signal to the relay 38 to cut off the regulation circuit 37 via the relay 38. This stops the supply of abnormal three-phase AC power to the load. This can protect the load.

In addition, the processor 36a uses the display device 39 to inform the user that the output of the three-phase AC signal has been restricted. The display device 39 is a liquid crystal display device or an LED. In the case of a liquid crystal display device, a message indicating that an abnormality has occurred may be displayed to the user. In the case of an LED, lighting may indicate that an abnormality has occurred. The notification to the user may be performed by an audio output device instead of the display device 39 or in combination with the display device 39 . The audio output device outputs, for example, a warning sound indicating the occurrence of an abnormality.

As described above, according to the present embodiment, it is possible to provide a technique of generating three-phase AC signals using a plurality of external power feeders that output single-phase AC signals while ensuring protection performance for loads.

<Second embodiment>
In the first embodiment, as the monitoring circuit 36, a configuration example capable of detecting both the phase loss and the reverse phase of the three-phase AC signals (U to W) was exemplified, but only the phase loss or only the reverse phase can be detected. It may be a possible configuration. FIG. 5B shows an example of a reverse phase detection circuit that replaces the sensors 36u to 36w.

In the illustrated example, resistors R1 and R2 are provided in series with the signal input lines from the U phase and W phase, respectively. Directly connected capacitor C and resistor R3 are connected between these resistors R1 and R2, and a V-phase signal input line is connected between capacitor C and resistor R3. A voltage sensor 36uw is connected in parallel with the series-connected capacitor C and resistor R3. When the phase is reversed, the voltage detected by the voltage sensor 36uw becomes approximately zero. A threshold voltage is set in advance, and when the voltage detected by the voltage sensor 36uw is equal to or lower than the threshold voltage, it can be determined that a reverse phase has occurred.

In the case of this embodiment, as the monitoring circuit 36, a circuit configuration other than a microcomputer including a processing section 36a, a storage section 36b, and an I/F section 36c can be employed. For example, instead of the microcomputer, a comparator that compares the voltage detected by the voltage sensor 36uw and the threshold voltage can be provided, and the comparison result of the comparator can be input to the relay 38 or the display device 39 such as an LED. Further, instead of the voltage sensor 36uw, a comparator is provided to which the voltage of the capacitor C and the resistor R3 connected in series and the threshold voltage are respectively input, and the comparison result of the comparator is displayed by the relay 38 or the display device 39 such as an LED. may be entered in the

<Third Embodiment>
By correcting the phase difference α and phase difference β shown in FIG. FIG. 6 is a diagram showing the configuration of the power supply control device 30 in this embodiment. The difference from the configuration example of FIG. 3 is that the control circuit 32 and the phase synchronization units 33 and 34 of the configuration example of FIG. 3 are not provided.

Elimination of the phase difference α and the phase difference β in FIG. 4 is performed in the external power feeders 20B and 20C. In the case of this embodiment, the single-phase AC signals are output in order from the external power feeders 20A to 20C. In other words, the user connects the external power feeders 20A to 20C to the power feed control device 30 and then sequentially operates the external power feeders 20A to 20C. A specific example will be described.

The user first outputs two single-phase AC signals U1 and V1 (see FIG. 4) having a voltage phase difference of 120° from the external power feeder 20A. Next, the user instructs to output two single-phase AC signals having a voltage phase difference of 120° from the external power feeder 20B. At this time, the control circuit 23 of the external power feeder 20B acquires the detection result of the voltage/current sensor S1. The single-phase AC signal V1 output from the external power feeder 20A is input to the connection terminal 26a of the external power feeder 20B via the generation section 35 of the power feed control device 30 and the connector 30b of the I/F section 31. Therefore, the voltage phase of the single-phase AC signal V1 can be specified from the detection result of the voltage/current sensor S1 of the external power feeder 20B. Therefore, the control circuit 23 of the external power feeder 20B outputs from the inverter circuit 22a a single-phase AC signal synchronized with the voltage phase of the single-phase AC signal V1 without a phase difference, that is, the single-phase AC signal V2' shown in FIG. is output, and the single-phase AC signal W1' in FIG. 4 is output from the inverter circuit 22b.

Next, the user instructs to output two single-phase AC signals having a voltage phase difference of 120° from the external power feeder 20C. At this time, the control circuit 23 of the external power feeder 20C acquires the detection result of the voltage/current sensor S1. A single-phase AC signal W1' output from the external power feeder 20B is input to the connection terminal 26a of the external power feeder 20C via the generator 35 of the power feed control device 30 and the connector 30b of the I/F section 31. Therefore, the voltage phase of the single-phase AC signal W1' can be specified from the detection result of the voltage/current sensor S1 of the external power feeder 20B. Therefore, the control circuit 23 of the external power feeder 20C outputs a single-phase AC signal synchronized with the voltage phase of the single-phase AC signal W1' without a phase difference from the inverter circuit 22a, that is, the single-phase AC signal W2 shown in FIG. ' is output, and the single-phase AC signal U21' in FIG. 4 is output from the inverter circuit 22b.

As described above, the single-phase AC signals U1 and U2′, the single-phase AC signals V1 and V2′, and the single-phase AC signals W1′ and W2′ are supplied to the generation unit 35 of the power supply control device 30, and power is supplied. As an output of the control device 30, a three-phase AC signal (U to V) can be output as in the first embodiment.

<Other embodiments>
In each of the above-described embodiments, a configuration example in which each of the external power feeders 20A to 20C outputs a two-phase single-phase AC signal was exemplified, but each of the external power feeders 20A to 20C is configured to output a single-phase single-phase AC signal. may be

Also, the external power feeders 20A to 20C may be generators that do not use the battery BT of the vehicle VEH as a power source.

<Summary of embodiment>
The above embodiments disclose at least the following power supply system and power supply control device.

1. The power supply system (1) of the above embodiment includes:
A first external power feeder (20A), a second external power feeder (20B), and a second three external feeders (20C);
Three-phase AC signals (U, V, a power supply control device (30) that generates and outputs W);
A power system comprising:
The power supply control device,
a monitoring means (36) for monitoring the three-phase AC signal generated by the power supply control device;
and regulation means (37) for regulating the output of the three-phase AC signal when the monitoring means detects that there is an abnormality in the three-phase AC signal.
According to this embodiment, it is possible to provide a technique of generating a three-phase AC signal using a plurality of external power feeders that output single-phase AC signals while ensuring protection performance for a load.

2. In the power supply system (1) of the above embodiment,
The monitoring means monitors the presence or absence of an open phase.
According to this embodiment, it is possible to prevent the performance of the load receiving power from deteriorating due to the phase loss in the three-phase AC signal, and to ensure the protection performance of the load.

3. In the power supply system (1) of the above embodiment,
The monitoring means monitors the presence or absence of a reversed phase.
According to this embodiment, it is possible to prevent the performance of the load receiving power from deteriorating due to the three-phase AC signal having the opposite phase, and to ensure the protection performance of the load.

4. In the power supply system (1) of the above embodiment,
The power supply control device includes an informing means (39) for informing a user that the regulating means has regulated the output of the three-phase AC signal.
According to this embodiment, it is possible to inform the user that the output of the three-phase AC signal is restricted.

5. In the power supply system (1) of the above embodiment,
The monitoring means includes sensors (36u, 36v, 36w) that detect at least one of the voltage or current of each phase of the three-phase AC signal, and based on the detection results of the sensors, the presence or absence of an abnormality is detected. judge.
According to this embodiment, it is possible to monitor multiple types of abnormalities such as phase loss and reversed phase.

6. The power supply control device (30) of the above embodiment includes:
A three-phase AC signal is generated by synchronizing the single-phase AC signals output from the first external power feeder ( ), the second external power feeder ( ), and the third external power feeder ( ) with a phase difference of 120°. A power supply control device that outputs by
monitoring means (36) for monitoring the generated three-phase AC signal;
and regulation means (37) for regulating the output of the three-phase AC signal when the monitoring means detects that there is an abnormality in the three-phase AC signal.
According to this embodiment, it is possible to provide a technique of generating a three-phase AC signal using a plurality of external power feeders that output single-phase AC signals while ensuring protection performance for a load.

The present invention is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

10: power supply system, 20A to 20C: external power supply, 30: power supply control device, 36: monitoring circuit, 37: regulation circuit

Claims (6)

a first external power feeder, a second external power feeder, and a third external power feeder, which are connected to a vehicle battery and convert DC power stored in the battery into single-phase AC power;
A three-phase AC signal is generated and output by synchronizing the single-phase AC signals output from the first external power feeder, the second external power feeder, and the third external power feeder with a phase difference of 120°. a power supply control device that
A power system comprising:
The power supply control device,
monitoring means for monitoring the three-phase AC signal generated by the power supply control device;
a regulation means for regulating the output of the three-phase AC signal when the monitoring means detects that there is an abnormality in the three-phase AC signal;
A power system characterized by: The power system of claim 1, comprising:
The monitoring means monitors the presence or absence of an open phase,
A power system characterized by: The power supply system according to claim 1 or claim 2,
The monitoring means monitors the presence or absence of a reversed phase.
A power system characterized by: The power supply system according to any one of claims 1 to 3,
The power supply control device includes notifying means for notifying a user that the restricting means has restricted the output of the three-phase AC signal.
A power system characterized by: The power supply system according to any one of claims 1 to 4,
The monitoring means includes a sensor that detects at least one of the voltage or current of each phase of the three-phase AC signal, and determines the presence or absence of an abnormality based on the detection result of the sensor.
A power system characterized by: Power supply control for generating and outputting a three-phase AC signal obtained by synchronizing the single-phase AC signals output from the first external power feeder, the second external power feeder, and the third external power feeder with a phase difference of 120°. a device,
monitoring means for monitoring the generated three-phase AC signal;
a regulation means for regulating the output of the three-phase AC signal when the monitoring means detects that there is an abnormality in the three-phase AC signal;
A power supply control device characterized by:

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