JP7041600B2 - Power system - Google Patents

Description

The present invention relates to a power supply system.

In recent years, for example, a vehicle such as an automobile is loaded with various loads that are driven by a plurality of different voltages. In order to supply electric power to such various loads, a power supply system capable of supplying different voltages is known (for example, Patent Document 1).

Jitsukaisho 63-333337 Publication No.

The power supply system includes, for example, a plurality of batteries depending on different voltages supplied to the load. Such a power supply system may not be able to supply power if, for example, one of the plurality of batteries fails.

An object of the present invention made in view of this point is to provide a power supply system with improved reliability.

In order to solve the above problems, the power supply system according to the first viewpoint is
Multiple converters connected in a loop and capable of bidirectional power conversion,
In the plurality of converters, a plurality of batteries provided between adjacent converters and
With a controller that can control the multiple converters,
Equipped with
The plurality of batteries are
With the first battery
A second battery whose nominal voltage is lower than that of the first battery,
Includes a third battery, which has a lower nominal voltage than the second battery.
The plurality of converters
A first converter capable of bidirectional power conversion between the first battery and the second battery,
A second converter capable of bidirectional power conversion between the second battery and the third battery,
Includes a third converter capable of bidirectional power conversion between the third battery and the first battery.

According to the power supply system according to the first aspect, reliability can be improved.

It is a block diagram of the power supply system which concerns on 1st Embodiment. It is a figure explaining the electric power path at the time of abnormality of the 1st battery with the configuration shown in FIG. It is a figure explaining the electric power path at the time of abnormality of the 2nd battery by the structure shown in FIG. It is a figure explaining the electric power path at the time of abnormality of the 3rd battery by the structure shown in FIG. It is a figure explaining the electric power path at the time of abnormality of the 1st converter by the structure shown in FIG. It is a figure explaining the electric power path at the time of abnormality of the 3rd converter by the structure shown in FIG. It is a flowchart which shows an example of the operation of the power-source system which concerns on 1st Embodiment. It is a flowchart which shows the other example of the operation of the power-source system which concerns on 1st Embodiment. It is a circuit diagram of the DC-DC converter which concerns on 2nd Embodiment. It is a circuit diagram of the AC-DC converter which concerns on 2nd Embodiment. It is a perspective view of the planar type transformer which concerns on 2nd Embodiment. It is sectional drawing of the planar type transformer in the LL line shown in FIG. It is a circuit diagram of the DC-DC converter which concerns on another example of 2nd Embodiment.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Hereinafter, the power supply system of the present disclosure will be described as being mounted on a vehicle such as a hybrid vehicle or an electric vehicle. However, the power supply system of the present disclosure may be mounted on any device that consumes power.

(First Embodiment)
[System configuration]
FIG. 1 is a block diagram of the power supply system 1 according to the first embodiment. In FIG. 1, the solid line connecting each block shows the flow of electric power. Further, in FIG. 1, the broken line connecting each block indicates the flow of control.

The power supply system 1 is mounted on a vehicle such as a hybrid vehicle or an electric vehicle. The power supply system 1 is connected to the AC power supply 2 when charging the first battery 21, which will be described later. The AC power supply 2 may be provided in a house, a charging stand, or the like. The AC power supply 2 may be a commercial AC power supply. The AC power supply 2 may be a three-phase type AC power supply. Alternatively, the AC power supply 2 may be a single-phase three-wire type AC power supply or a single-phase two-wire type AC power supply. The AC power supply 2 can supply an AC voltage in the range of, for example, 85V to 265V.

The power supply system 1 includes a first converter 11, a second converter 12, and a third converter 13 connected in a loop. Further, the power supply system 1 includes a first battery 21, a second battery 22, a third battery 23, a motor 31, an auxiliary device 32, an electronic control unit (ECU) 33, and a memory 40. , And a controller 41. In addition, the power supply system 1 may include a fourth converter 14.

In the power supply system 1 shown in FIG. 1, three converters, a first converter 11, a second converter 12, and a third converter 13, are connected in a loop. However, in the power supply system 1, for example, two converters may be connected in a loop shape, or four or more converters may be connected in a loop shape, depending on the number of batteries.

Hereinafter, the nominal voltage of the first battery 21 is assumed to be a high voltage in the range of, for example, 250V to 450V (hereinafter, referred to as “HV”). However, the nominal voltage of the first battery 21 may be an arbitrary voltage according to the drive voltage of the motor 31. Further, it is assumed that the nominal voltage of the second battery 22 is 48V. However, if the nominal voltage of the second battery 22 is lower than the nominal voltage of the first battery 21, it may be any voltage according to the driving voltage of the auxiliary device 32. Further, it is assumed that the nominal voltage of the third battery 23 is 12V. However, the nominal voltage of the third battery 23 may be any voltage according to the driving voltage of the ECU 33 as long as it is lower than the nominal voltage of the second battery 22.

The first converter 11 may be configured to include a switching element, an inductor, and the like. The first converter 11 is capable of bidirectional power conversion. The first converter 11 is, for example, a bidirectional DC-DC converter. The first converter 11 is capable of bidirectional power conversion between the first battery 21 and the second battery 22.

For example, the first converter 11 lowers the voltage HV supplied from the first battery 21 to a voltage suitable for charging the second battery 22 based on the control of the controller 41, and lowers the DC voltage after the lowering to the second. It is supplied to the battery 22. Alternatively, the first converter 11 lowers the voltage HV supplied from the first battery 21 to a voltage suitable for driving the auxiliary device 32 based on the control of the controller 41, and lowers the DC voltage after the step-down to the auxiliary device 32. Supply to 32. Alternatively, the first converter 11 boosts the voltage 48V supplied from the second battery 22 to a voltage suitable for driving the motor 31 based on the control of the controller 41, and supplies the boosted DC voltage to the motor 31. do.

The second converter 12 may be configured to include a switching element, an inductor, and the like. The second converter 12 is capable of bidirectional power conversion. The second converter 12 is, for example, a bidirectional DC-DC converter. The second converter 12 is capable of bidirectional power conversion between the second battery 22 and the third battery 23.

For example, the second converter 12 lowers the voltage 48V supplied from the second battery 22 to a voltage suitable for charging the third battery 23 based on the control of the controller 41, and lowers the DC voltage after the lowering to the third. It is supplied to the battery 23. Alternatively, the second converter 12 boosts the voltage 12V supplied from the third battery 23 to a voltage suitable for charging the second battery 22 based on the control of the controller 41, and raises the boosted DC voltage to the second. It is supplied to the battery 22. Alternatively, the second converter 12 lowers the 48V supplied from the second battery 22 to a voltage suitable for driving the ECU 33 based on the control of the controller 41, and supplies the DC voltage after the lowering to the ECU 33.

The third converter 13 may be configured to include a switching element, an inductor, and the like. The third converter 13 is capable of bidirectional power conversion. The third converter 13 is, for example, a bidirectional DC-DC converter. The third converter 13 is capable of bidirectional power conversion between the first battery 21 and the third battery 23.

For example, the third converter 13 lowers the voltage HV supplied from the first battery 21 to a voltage suitable for charging the third battery 23 based on the control of the controller 41, and lowers the DC voltage after the lowering to the third. It is supplied to the battery 23. Alternatively, the third converter 13 lowers the voltage HV supplied from the first battery 21 to a voltage suitable for driving the ECU 33 based on the control of the controller 41, and supplies the DC voltage after the lowering to the ECU 33. Alternatively, the third converter 13 boosts the voltage 12V supplied from the third battery 23 to a voltage suitable for driving the motor 31 based on the control of the controller 41, and supplies the boosted DC voltage to the motor 31. do.

The fourth converter 14 may be configured to include a switching element, an inductor, and the like. The fourth converter 14 is capable of bidirectional power conversion. The fourth converter 14 is, for example, a bidirectional AC-DC converter.

For example, the fourth converter 14 converts the AC power supplied from the AC power supply 2 into DC power based on the control of the controller 41. Further, the fourth converter 14 boosts the converted DC power voltage to the voltage HV based on the control of the controller 41. The fourth converter 14 supplies the boosted DC voltage to the first battery 21.

The first battery 21 may be configured to include a lithium ion battery. The first battery 21 is provided between the first converter 11 and the third converter 13. For example, the terminal on the positive electrode side of the first battery 21 is connected between the first converter 11 and the third converter 13. The first battery 21 and the motor 31 are isolated from the outside.

The first battery 21 is charged by the electric power supplied from the AC power source 2 via, for example, the fourth converter 14. The first battery 21 can supply DC power to at least one of the first converter 11, the third converter 13, and the motor 31 by discharging the charged power.

The first battery 21 is used to supply electric power to the motor 31. Therefore, the nominal capacity of the first battery 21 is larger than the nominal capacity of the second battery 22 and the nominal capacity of the third battery. Therefore, in the power supply system 1, the first battery 21 is charged by the electric power from the AC power supply 2. Next, by discharging the electric power charged in the first battery 21, the second battery 22 and the third battery 23 are charged as described later.

The second battery 22 may be configured to include a lithium ion battery. The second battery 22 is provided between the first converter 11 and the second converter 12. For example, the terminal on the positive electrode side of the second battery is connected between the first converter 11 and the second converter 12. Further, the terminal on the negative electrode side of the second battery 22 is connected to the housing (body) of the vehicle on which the power supply system 1 is mounted.

The nominal voltage of the second battery 22 is lower than the nominal voltage of the first battery 21. The second battery 22 is charged by the electric power supplied from the first battery 21, for example, via the first converter 11. The second battery 22 can supply DC power to at least one of the first converter 11, the second converter 12, and the auxiliary machine 32 by discharging the charged power.

The third battery 23 may be configured to include a lithium ion battery. The third battery 23 is provided between the second converter 12 and the third converter 13. For example, the terminal on the positive electrode side of the third battery 23 is connected between the second converter 12 and the third converter 13. Further, the terminal on the negative electrode side of the third battery 23 is connected to the housing (body) of the vehicle on which the power supply system 1 is mounted.

The nominal voltage of the third battery 23 is lower than the nominal voltage of the second battery 22. The third battery 23 is charged by the electric power supplied from the first battery 21, for example, via the third converter 13. The third battery 23 can supply DC power to at least one of the second converter 12, the third converter 13, and the ECU 33 by discharging the charged power.

The motor 31 generates a rotational driving force by the electric power supplied from the first battery 21. The rotational driving force generated by the motor 31 is transmitted to the tires of the vehicle equipped with the power supply system 1. The vehicle equipped with the power supply system 1 travels by transmitting the rotational driving force to the tires. The motor 31 may be an HEV motor or an EV motor.

The auxiliary machine 32 is driven by the electric power supplied from the second battery 22. In FIG. 1, one auxiliary machine 32 is connected to the second battery 22, but a plurality of auxiliary machines 32 may be connected to the second battery 22. The auxiliary machine 32 may be various devices included in the vehicle on which the power supply system 1 is mounted. For example, the auxiliary machine 32 may be an electric power steering, an electric suspension, a sensor for automatic driving, an electric actuator, or the like.

The ECU 33 is driven by the electric power supplied from the third battery 23. In FIG. 1, one ECU 33 is connected to the third battery 23, but a plurality of ECU 33s may be connected to the third battery 23. The ECU 33 may be a control unit that controls the motor 31, a control unit that controls the equipment included in the auxiliary machine 32, or the like.

The memory 40 is connected to the controller 41. The memory 40 stores the information acquired from the controller 41. The memory 40 may function as a working memory of the controller 41. The memory 40 may store a program executed by the controller 41. The memory 40 is composed of, for example, a semiconductor memory, but is not limited to this, and may be composed of a magnetic storage medium or another storage medium. The memory 40 may be included as part of the controller 41.

The controller 41 may be configured by a processor such as a CPU (Central Processing Unit) that executes a program that defines a control procedure. The controller 41 may be a kind of ECU 33.

The controller 41 can control the first converter 11, the second converter 12, the third converter 13, and the fourth converter 14. For example, the controller 41 controls the first converter 11 and the like by outputting a control signal to the first converter 11 and the like.

The controller 41 may be able to detect an abnormality in the first battery 21, the second battery 22, and the third battery 23.

For example, when the first battery 21 fails, the controller 41 detects that the first battery 21 is abnormal. In this case, the controller 41 may detect the failure of the first battery 21 by the BMS (Battery Management System) that monitors the voltage of each cell included in the first battery 21. Similarly, for example, the controller 41 detects that the second battery 22 is abnormal when the second battery 22 fails. Similarly, for example, the controller 41 detects that the third battery 23 is abnormal when the third battery 23 fails.

For example, the controller 41 detects that the first battery 21 is abnormal when the terminal of the first battery 21 is released from the first converter 11 or the like and when the terminal of the first battery 21 is short-circuited. The open terminal is also called an "open terminal". A short-circuited terminal is also referred to as a "short-circuited terminal". In this case, the controller 41 may detect the open terminal and the short terminal in the first battery 21 by monitoring the voltage between the terminals of the first battery 21. Similarly, for example, when the controller 41 detects an open terminal or a short terminal in the second battery 22, it detects that the second battery 22 is abnormal. Similarly, for example, when the controller 41 detects an open terminal or a short terminal in the third battery 23, the controller 41 detects that the third battery 23 is abnormal.

The controller 41 may be able to detect an abnormality in the first converter 11, the second converter 12, and the third converter 13.

For example, the controller 41 detects that the first converter 11 is abnormal when the output current or the output voltage of the first converter 11 is out of the predetermined range. In this case, the controller 41 may detect the abnormality of the first converter 11 by monitoring the output of the first converter 11. Similarly, for example, the controller 41 detects that the second converter 12 is abnormal when the output current or the output voltage of the second converter 12 is out of the predetermined range. Similarly, for example, the controller 41 detects that the third converter 13 is abnormal when the output current or the output voltage of the third converter 13 is out of the predetermined range.

[Normal]
The controller 41 controls the fourth converter 14 by outputting a control signal to the fourth converter 14 while the power supply system 1 is connected to the AC power supply 2, and the first battery is powered by the power from the AC power supply 2. 21 is charged.

For example, the controller 41 controls the first converter 11 and the third converter 13 while the vehicle equipped with the power supply system 1 is running, and transfers the electric power supplied to the first battery 21 to the second battery 22 and the third battery 23. Supply to. The power paths at this time are the path P1 and the path P2 shown in FIG. The path P1 is a path of electric power flowing from the first battery 21 to the second battery 22 via the first converter 11. The path P2 is a path of electric power flowing from the first battery 21 to the third battery 23 via the third converter 13.

By such control, the second battery 22 can be charged to supply electric power to the auxiliary device 32. Further, by such control, the third battery 23 can be charged to supply electric power to the ECU 33 and the controller 41.

[When the first battery is abnormal]
When the controller 41 detects an abnormality in the first battery 21, the failed first battery is disconnected from other circuit elements by means such as a relay (not shown). After that, the controller 41 controls the first converter 11 to supply the electric power charged in the second battery 22 to the motor 31 as a load connected to the first battery 21. The power path at this time is the path P3 shown in FIG. The path P3 is a path of electric power flowing from the second battery 22 to the motor 31 via the first converter 11.

By such control, even if an abnormality occurs in the first battery 21, the motor 31 can continue to be driven for a while by the electric power supplied from the second battery 22. That is, the vehicle equipped with the power supply system 1 can continue to drive the motor 31 for a while even if an abnormality occurs in the first battery 21 during traveling, for example. This allows the vehicle to travel to a safe position, such as on the side of a road, and then stop.

The controller 41 controls the third converter 13 when, for example, the charge rate SOC of the second battery 22 falls below a predetermined value, and the electric power charged in the third battery 23 is connected to the first battery 21. It may be supplied to the motor 31 as a load. The power path at this time is the path P4 shown in FIG. The path P4 is a path of electric power flowing from the third battery 23 to the motor 31 via the third converter 13.

[When the second battery is abnormal]
When the controller 41 detects an abnormality in the second battery 22, the controller 41 disconnects the failed second battery 22 from other circuit elements by means such as a relay (not shown). After that, the controller 41 controls the first converter 11 to supply the electric power charged in the first battery 21 to the auxiliary device 32 as a load connected to the second battery 22. The power path at this time is the path P5 shown in FIG. The path P5 is a path of electric power flowing from the first battery 21 to the auxiliary device 32 via the first converter 11.

By such control, even if an abnormality occurs in the second battery 22, the auxiliary machine 32 can continue to be driven by the electric power from the first battery 21. That is, the vehicle equipped with the power supply system 1 can drive the auxiliary machine 32 even if an abnormality occurs in the second battery 22 during traveling, for example.

The controller 41 may control the second converter 12 and the third converter 13 to supply the electric power charged in the first battery 21 to the auxiliary machine 32 as a load connected to the second battery 22. good. For example, when the controller 41 detects an abnormality in the first converter 11 in addition to an abnormality in the second battery 22, it controls the second converter 12 and the third converter 13 to supplement the power from the first battery 21. It may be supplied to the machine 32. The power path at this time is the path P6 shown in FIG. The path P6 is a path of electric power flowing from the first battery 21 to the auxiliary device 32 via the third converter 13 and the second converter 12.

[When the third battery is abnormal]
When the controller 41 detects an abnormality in the third battery 23, the controller 41 disconnects the failed third battery 23 from other circuit elements by means such as a relay (not shown). After that, the controller 41 controls the third converter 13 to supply the electric power charged in the first battery 21 to the ECU 33 and the controller 41 as a load connected to the third battery 23. The power path at this time is the path P7 shown in FIG. The path P7 is a path of electric power flowing from the first battery 21 to the ECU 33 or the like via the third converter 13.

By such control, even if an abnormality occurs in the third battery 23, the ECU 33 and the like can continue to be driven by the electric power from the first battery 21. That is, the vehicle equipped with the power supply system 1 can continue to drive the ECU 33 and the like even if an abnormality occurs in the third battery 23 while traveling, for example.

When the controller 41 detects, for example, an abnormality of the third converter 13 in addition to an abnormality of the third battery 23, the controller 41 controls the second converter 12 to use the electric power charged in the second battery 22 as the third battery. It may be supplied to the ECU 33 or the like as a load connected to the 23. The power path at this time is the path P8 shown in FIG. The path P8 is a path of electric power flowing from the second battery 22 to the ECU 33 or the like via the second converter 12.

[When the first converter is abnormal]
When the controller 41 detects an abnormality in the first converter 11, the controller 41 disconnects the first converter 11 from other circuit elements by means such as a relay (not shown). The controller 41 controls the second converter 12 and the third converter 13 to supply the electric power charged in the first battery 21 to the second battery 22 and the third battery 23. The power path at this time is the path P9 shown in FIG. The path P9 is a path of electric power flowing from the first battery 21 to the third battery 23 via the third converter 13, and from the first battery 21 to the second battery 22 via the third converter 13 and the second converter 12. It is a path of flowing power.

By such control, even if an abnormality occurs in the first converter 11, the second battery 22 and the third battery 23 can be charged by the electric power from the first battery 21. As a result, the auxiliary machine 32 can continue to be driven by the electric power supplied from the second battery 22. Further, the ECU 33 and the controller 41 can continue to be driven by the electric power supplied from the third battery 23.

[When the third converter is abnormal]
When the controller 41 detects an abnormality in the third converter 13, the controller 41 disconnects the third converter 13 from other circuit elements by means such as a relay (not shown). The controller 41 controls the first converter 11 and the second converter 12 to supply the electric power charged in the first battery 21 to the second battery 22 and the third battery 23. The power path at this time is the path P10 shown in FIG. The path P10 is a path of electric power flowing from the first battery 21 to the second battery 22 via the first converter 11, and from the first battery 21 to the third battery 23 via the first converter 11 and the second converter 12. It is a path of flowing power.

By such control, even if an abnormality occurs in the third converter 13, the second battery 22 and the third battery 23 can be charged by the electric power from the first battery 21. As a result, the auxiliary machine 32 can continue to be driven by the electric power supplied from the second battery 22. Further, the ECU 33 and the controller 41 can continue to be driven by the electric power supplied from the third battery 23.

[System operation]
FIG. 7 is a flowchart showing an example of the operation of the power supply system 1 according to the first embodiment. For example, the controller 41 starts the process shown in FIG. 7 when the vehicle equipped with the power supply system 1 starts traveling. Further, when the vehicle equipped with the power supply system 1 stops traveling, the controller 41 ends the process shown in FIG. 7.

The controller 41 determines whether or not the first battery 21 is abnormal (step S10). When the controller 41 determines that the first battery 21 is abnormal (step S10: Yes), the controller 41 proceeds to the process of step S11. On the other hand, when the controller 41 does not determine that the first battery 21 is abnormal (step S10: No), the controller 41 proceeds to the process of step S12.

In the process of step S11, the controller 41 controls the first converter 11 to supply the electric power charged in the second battery 22 to the motor 31 as a load connected to the first battery 21 (see: FIG. Route 2 P3).

In the process of step S12, the controller 41 determines whether or not the second battery 22 is abnormal. When the controller 41 determines that the second battery 22 is abnormal (step S12: Yes), the controller 41 proceeds to the process of step S13. On the other hand, when the controller 41 does not determine that the second battery 22 is abnormal (step S12: No), the controller 41 proceeds to the process of step S14.

In the process of step S13, the controller 41 controls the first converter 11 to supply the electric power charged in the first battery 21 to the auxiliary machine 32 as a load connected to the second battery 22 (see:: Route P5 in FIG. 3).

In the process of step S14, the controller 41 determines whether or not the third battery 23 is abnormal. When the controller 41 determines that the third battery 23 is abnormal (step S14: Yes), the controller 41 proceeds to the process of step S15. On the other hand, when the controller 41 does not determine that the third battery 23 is abnormal (step S14: No), the controller 41 returns to the process of step S10.

In the process of step S15, the controller 41 controls the third converter 13 to supply the electric power charged in the first battery 21 to the ECU 33 and the controller 41 as a load connected to the third battery 23 (see). : Route P7 in FIG. 4).

In the process of step S11, the controller 41 may control the third converter 13 to supply the electric power charged in the third battery 23 to the motor 31 as a load connected to the first battery 21. Good (see: Path P4 in FIG. 2).

Further, in the process of step S13, the controller 41 controls the second converter 12 and the third converter 13, and the electric power charged in the first battery 21 is used as a load connected to the second battery 22. It may be supplied to the auxiliary machine 32 (see: path P6 in FIG. 3).

Further, in the process of step S15, the controller 41 may control the second converter 12 to supply the electric power charged in the second battery 22 to the ECU 33 or the like as a load connected to the third battery 23. Good (see: Path P8 in FIG. 4).

FIG. 8 is a flowchart showing another example of the operation of the power supply system 1 according to the first embodiment. For example, the controller 41 starts the process shown in FIG. 8 when the vehicle equipped with the power supply system 1 starts traveling. Further, when the vehicle equipped with the power supply system 1 stops traveling, the controller 41 ends the process shown in FIG. The controller 41 may execute the process shown in FIG. 8 in parallel with the process shown in FIG. 7.

The controller 41 determines whether or not the first converter 11 is abnormal (step S20). When the controller 41 determines that the first converter 11 is abnormal (step S20: Yes), the controller 41 proceeds to the process of step S21. On the other hand, when the controller 41 does not determine that the first converter 11 is abnormal (step S20: No), the controller 41 proceeds to the process of step S22.

In the process of step S21, the controller 41 controls the second converter 12 and the third converter 13 to supply the electric power charged in the first battery 21 to the second battery 22 and the third battery 23 (see: Route P9 in FIG. 5).

In the process of step S22, the controller 41 determines whether or not the third converter 13 is abnormal. When the controller 41 determines that the third converter 13 is abnormal (step S22: Yes), the controller 41 proceeds to the process of step S23. On the other hand, when the controller 41 does not determine that the third converter 13 is abnormal (step S22: No), the controller 41 returns to the process of step S20.

In the process of step S23, the controller 41 controls the first converter 11 and the second converter 12 to supply the electric power charged in the first battery 21 to the second battery 22 and the third battery 23 (see:: Route P10 in FIG. 6).

As described above, in the power supply system 1 according to the first embodiment, as shown in FIG. 1, the first converter 11, the second converter 12, and the third converter 13 are connected in a loop. Further, the first battery 21 is provided between the first converter 11 and the third converter 13, the second battery 22 is provided between the first converter 11 and the second converter 12, and the third battery 23 is the first. It is provided between the 2 converter 12 and the 3rd converter. With such a configuration, power can be continuously supplied to the load even if an abnormality occurs in any of the first converter 11 and the like and the first battery 21 and the like included in the power supply system 1. Therefore, according to the first embodiment, the power supply system 1 with improved reliability can be provided.

(Second Embodiment)
In the second embodiment, the circuit configurations that can be adopted for the first converter 11, the second converter 12, the third converter 13, and the fourth converter 14 will be described.

[Circuit configuration of DC-DC converter]
The circuit configurations that can be adopted for the first converter 11, the second converter 12, and the third converter 13 will be described with reference to FIG. Hereinafter, when the first converter 11, the second converter 12, and the third converter 13 are not particularly distinguished, they are collectively referred to as “converter 10”.

FIG. 9 is a circuit diagram of the DC-DC converter according to the second embodiment. In other words, FIG. 9 is a circuit diagram of the converter 10. The converter 10 is connected between the battery 20A and the battery 20B. The nominal voltage of the battery 20A shall be lower than the nominal voltage of the battery 20B. That is, when the converter 10 is the first converter 11, the battery 20A becomes the second battery 22 shown in FIG. 1, and the battery 20B becomes the first battery 21 shown in FIG. When the converter 10 is the second converter 12, the battery 20A becomes the third battery 23 shown in FIG. 1, and the battery 20B becomes the second battery 22 shown in FIG. When the converter 10 is the third converter 13, the battery 20A becomes the third battery 23 shown in FIG. 1, and the battery 20B becomes the first battery 21 shown in FIG.

The converter 10 includes a drive circuit 50, switching circuits 51A and 51B, smoothing capacitors 52A and 52B, and a transformer 60. Further, the converter 10 may include switches 90A and 90B for disconnecting the transformer and the circuit.

The drive circuit 50 generates a drive signal of a pulse wave that turns on and off the switching circuits 51A and 51B at a predetermined timing based on the control signal from the controller 41 shown in FIG. The frequency of the drive signal, which is a pulse wave, is also referred to as "drive frequency". The drive circuit 50 outputs the generated drive signal to the switching circuits 51A and 51B.

The drive circuit 50 generates a control signal for controlling the switches 90A and 90B on and off based on the control signal from the controller 41 shown in FIG. The drive circuit 50 outputs the generated control signal to the switches 90A and 90B. The controller 41 turns on the 90A90B when operating the converter 10, and turns it off at other times.

The switching circuit 51A is connected between the battery 20A and the transformer 60. The switching circuit 51A is a full bridge type circuit. When the converter 10 boosts the voltage on the battery 20A side to the voltage on the battery 20B side, the switching circuit 51A is driven by the drive signal from the drive circuit 50. The switching circuit 51A has switching elements Q1A, Q2A, QA3, and Q4A.

The switching elements Q1A to Q4A may be N-type MOSFETs. For example, the switching elements Q1A to Q4A may be power MOSFETs. The switching elements Q1A to Q4A are not limited to MOSFETs. For example, the switching elements Q1A to Q4A may be bipolar transistors or IGBTs (Insulated Gate Bipolar Transistors).

The drains of the switching elements Q1A and Q3A are connected to the terminals on the positive electrode side of the battery 20A. The sources of the switching elements Q2A and Q4A are connected to the terminals on the negative electrode side of the battery 20A. The source of the switching element Q1A and the drain of the switching element Q2A are connected to one end of the winding 70 of the transformer 60. The source of the switching element Q3A and the drain of the switching element Q4A are connected to the other end of the winding 70 of the transformer 60.

A drive signal from the drive circuit 50 is input to the gates of the switching elements Q1A to Q4A. When the switching elements Q1A and Q4A are turned on by the input of the drive signal, the switching elements Q2A and Q3A are turned off. Further, when the switching elements Q1A and Q4A are turned off, the switching elements Q2A and Q3A are turned on. In other words, when the drive signal is input, the switching elements Q1A and Q4A and the switching elements Q2A and Q3A are alternately turned on and off at the drive frequency. When the switching elements Q1A and Q4A and the switching elements Q2A and Q3A are alternately turned on and off at the drive frequency, an alternating current at the drive frequency flows through the winding 70 of the transformer 60. When an alternating current flows through the winding 70 of the transformer 60, an induced electromotive force is generated in the winding 80 of the transformer 60.

The switching circuit 51B is connected between the battery 20B and the transformer 60. The switching circuit 51B is a full bridge type circuit. When the converter 10 steps down the voltage on the battery 20B side to the voltage on the battery 20A side, the switching circuit 51B is driven by the drive signal from the drive circuit 50. The switching circuit 51B has switching elements Q1B, Q2B, Q3B, and Q4B.

The switching elements Q1B to Q4B may be N-type MOSFETs. For example, the switching elements Q1B to Q4B may be power MOSFETs. The switching elements Q1B to Q4B are not limited to MOSFETs. For example, the switching elements Q1B to Q4B may be bipolar transistors or IGBTs.

The drains of the switching elements Q1B and Q3B are connected to the terminals on the positive electrode side of the battery 20B. The sources of the switching elements Q2B and Q4B are connected to the terminals on the negative electrode side of the battery 20B. The source of the switching element Q1B and the drain of the switching element Q2B are connected to one end of the winding 80 of the transformer 60. The source of the switching element Q3B and the drain of the switching element Q4B are connected to the other end of the winding 80 of the transformer 60.

A drive signal from the drive circuit 50 is input to the gates of the switching elements Q1B to Q4B. When the switching elements Q1B and Q4B are turned on by the input of the drive signal, the switching elements Q2B and Q3B are turned off. Further, when the switching elements Q1B and Q4B are turned off, the switching elements Q2B and Q3B are turned on. In other words, when the drive signal is input, the switching elements Q1B and Q4B and the switching elements Q2B and Q3B are alternately turned on and off at the drive frequency. When the switching elements Q1B and Q4B and the switching elements Q2B and Q3B are alternately turned on and off at the drive frequency, an alternating current at the drive frequency flows through the winding 80 of the transformer 60. When an alternating current flows through the winding 80 of the transformer 60, an induced electromotive force is generated in the winding 70 of the transformer 60.

The smoothing capacitor 52A is provided between the battery 20A and the switching circuit 51A. The smoothing capacitor 52A smoothes the voltage between the switching circuit 51A and the battery 20A.

The smoothing capacitor 52B is provided between the battery 20B and the switching circuit 51B. The smoothing capacitor 52B smoothes the voltage between the switching circuit 51B and the battery 20B.

The transformer 60 is an isolation transformer. The transformer 60 may be a planar type transformer. However, the transformer 60 is not limited to the planar type transformer. For example, the transformer 60 may be a transformer including a bobbin and a conductive wire.

Hereinafter, when the transformer 60 included in each of the first converter 11, the second converter 12, and the third converter 13 is distinguished, the transformer 60 included in the first converter 11 is referred to as “transformer 61”. Further, the transformer 60 included in the second converter 12 is described as "transformer 62". Further, the transformer 60 included in the third converter 13 is described as "transformer 63".

The transformer 60 has a core 65, a winding 70, and a winding 80. The transformers 61, 62, 63 share the core 65. This configuration will be described later with reference to FIGS. 11 and 12.

The winding 70 is formed as a conductor pattern when the transformer 60 is a planar type transformer. The winding 70 is also referred to as a "primary winding" when the converter 10 boosts the voltage on the battery 20A side to the voltage on the battery 20B side. Further, the winding 70 is also referred to as a "secondary winding" when the converter 10 lowers the voltage on the battery 20B side to the voltage on the battery 20A side. The number of turns of the winding 70 and the number of turns of the winding 80 are appropriately set based on the voltage that the converter 10 steps up and down.

Hereinafter, when the winding 70 included in each of the transformers 61 to 63 is distinguished, the winding 70 possessed by the transformer 61 (that is, possessed by the first converter 11) is referred to as "winding 71". Further, the winding 70 included in the transformer 62 (that is, the second converter 12 has) is described as "winding 72". Further, the winding 70 included in the transformer 63 (that is, the third converter 13 has) is described as "winding 73".

The winding 80 is formed as a conductor pattern when the transformer 60 is a planar type transformer. The winding 80 is also referred to as a "secondary winding" when the converter 10 boosts the voltage on the battery 20A side to the voltage on the battery 20B side. Further, the winding 70 is also referred to as a "primary winding" when the converter 10 lowers the voltage on the battery 20B side to the voltage on the battery 20A side.

Hereinafter, when the winding 80 included in each of the transformers 61 to 63 is distinguished, the winding 80 possessed by the transformer 61 (that is, possessed by the first converter 11) is described as "winding 81". Further, the winding 80 possessed by the transformer 62 (that is, possessed by the second converter 12) is described as "winding 82". Further, the winding 80 possessed by the transformer 63 (that is, possessed by the third converter 13) is described as "winding 83".

The switches 90A and 90B may be N-type MOSFETs like the switching element Q1A and the like. For example, the switches 90A and 90B may be power MOSFETs. The switches 90A and 90B are not limited to MOSFETs. For example, the switches 90A and 90B may be bipolar transistors or IGBTs.

Hereinafter, when the switches 90A and 90B included in the first converter 11, the second converter 12 and the third converter 13 are distinguished, the switches 90A and 90B included in the first converter 11 are "switch 91A" and "switch 91B". ". Further, the switch 90A and the switch 90B included in the second converter 12 are described as "switch 92A" and "switch 92B". Further, the switch 90A and the switch 90B included in the third converter 13 are described as "switch 93A" and "switch 93B".

The switch 90A is provided between the battery 20A and the switching circuit 51A. For example, the switch 90A is provided between the terminal on the negative electrode side of the battery 20A and the source of the switching element Q2A of the switching circuit 51A. The switch 90B is provided between the battery 20B and the switching circuit 51B. For example, the switch 90B is provided between the terminal on the negative electrode side of the battery 20B and the source of the switching element Q4B of the switching circuit 51B.

The switches 90A and 90B disconnect the transformer 60 from other components based on the control signal from the drive circuit 50. For example, the switch 90A disconnects the connection between the transformer 60 and the switching circuit 51A and the smoothing capacitor 52A and the battery 20A by turning off the switch 90A based on the control signal from the drive circuit 50. For example, the switch 90B disconnects the connection between the transformer 60 and the switching circuit 51B and the smoothing capacitor 52B and the battery 20B by turning off the switch 90B based on the control signal from the drive circuit 50.

The switch 90A may be provided between the terminal on the positive electrode side of the battery 20A and the drain of the switching element Q1A of the switching circuit 51A. Further, the switch 90B may be provided between the terminal on the positive electrode side of the battery 20B and the drain of the switching element Q3B of the switching circuit 51B. In this case, the switches 90A and 90B may be P-type MOSFETs.

[Circuit configuration of AC-DC converter]
FIG. 10 is a circuit diagram of the AC-DC converter according to the second embodiment. In other words, FIG. 10 is a circuit diagram of the fourth converter 14. The fourth converter 14 includes a converter 10 and a rectifier circuit 15.

The converter 10 is connected between the rectifier circuit 15 and the first battery 21. The converter 10 boosts the voltage from the rectifier circuit 15 to a predetermined voltage and then supplies the voltage to the first battery 21.

Hereinafter, the transformer 60 included in the converter 10 of the fourth converter 14 is also referred to as “transformer 64”. Further, the winding 70 of the transformer 64 is also described as “winding 74”. The winding 80 of the transformer 64 is also referred to as “winding 84”. The switch 90A and the switch 90B included in the converter 10 of the fourth converter 14 are also referred to as "switch 94A" and "switch 94B".

The transformer 64 may be configured by sharing the core 65 with the above-mentioned transformers 61, 62, 63. This configuration will be described later with reference to FIGS. 11 and 12.

The rectifier circuit 15 may be configured to include a switching element and an inductor. The rectifier circuit 15 may be a three-phase full-wave rectifier type circuit or a three-phase half-wave rectifier type circuit. The rectifier circuit 15 may be connected to the AC power supply 2. The rectifier circuit 15 converts the alternating current from the alternating current power supply 2 into a direct current by rectifying the alternating current.

[Transformer configuration]
FIG. 11 is a perspective view of the planar type transformer according to the second embodiment. FIG. 12 is a cross-sectional view of a planar transformer on the LL line shown in FIG. In FIG. 12, the magnetic flux of the closed magnetic path formed inside the core 65 is shown by a broken line.

As shown in FIGS. 11 and 12, the planar transformer 100 includes a core 65, windings 71, 72, 73, 74, windings 81, 82, 83, 84, and a substrate 110.

The core 65 may be made of a magnetic member such as ferrite. The core 65 may be configured by combining a pair of E-shaped cores having an E-shaped cross section so that the three legs face each other. As shown in FIG. 12, the core 65 includes a middle leg portion 66, side leg portions 67-1 and 67-2, an upper surface portion 68, and a lower surface portion 69.

As shown in FIGS. 11 and 12, the middle leg portion 66 is inserted into the opening located at the center of the windings 71 to 74 and the opening located at the center of the windings 81 to 84. In other words, the windings 71 to 74 and the windings 81 to 84 are wound around the middle leg portion 66. The middle leg portion 66 may be provided with a gap 66a. By providing the gap 66a in the middle leg portion 66, the magnetic flux density of the closed magnetic path formed inside the core 65 can be reduced, and magnetic saturation in the core 65 can be prevented.

As shown in FIG. 11, the side leg portion 67-1 is located on the outer side of one side of the substrate 110. The side legs 67-2 are located on the outside of the other side of the substrate 110, as shown in FIG.

As shown in FIG. 12, the upper surface portion 68 connects the upper portion of the middle leg portion 66 and the upper portion of the side leg portions 67-1 and 67-2. As shown in FIG. 12, the lower surface portion 69 connects the lower portion of the middle leg portion 66 and the lower portion of the side leg portions 67-1 and 67-2.

The windings 71 to 74 and 81 to 84 are conductor patterns formed by using a conductor such as copper. The windings 71 to 74 and 81 to 84 have an opening in the center thereof. As described above, the windings 71 and 81 are included in the transformer 61. Further, the windings 72 and 82 are included in the transformer 62. Further, the windings 73 and 83 are included in the transformer 63. Further, the windings 74 and 84 are included in the transformer 64.

The substrate 110 is configured to include an insulating material. As shown in FIG. 12, the substrate 110 includes the substrates 111, 112, 113, 114, 115, 116, 117, 118.

A winding 81 is arranged on the upper surface of the substrate 111. A winding 71 is arranged on the lower surface of the substrate 111. A winding 82 is arranged on the upper surface of the substrate 112. A winding 72 is arranged on the lower surface of the substrate 112. A winding 83 is arranged on the upper surface of the substrate 113. A winding 73 is arranged on the lower surface of the substrate 113. A winding 84 is arranged on the upper surface of the substrate 114. A winding 74 is arranged on the lower surface of the substrate 114.

The substrate 115 is arranged between the winding 71 and the winding 82. The substrate 116 is arranged between the winding 72 and the winding 83. The substrate 117 is arranged between the winding 73 and the winding 84.

As described above, the transformers 61 to 64 of the first converter 11, the second converter 12, the third converter 13, and the fourth converter 14 can be configured by sharing the core 65. With such a configuration, the first converter 11, the second converter 12, the third converter 13, and the fourth converter 14 can be miniaturized. Therefore, the power supply system 1 can be miniaturized. Further, by configuring the transformers 61 to 64 as planar transformers, the first converter 11, the second converter 12, the third converter 13 and the fourth converter 14 can be further miniaturized.

[Selection of drive frequency]
When the transformers 61 to 64 share the core 65, magnetic saturation in the core 65 can be prevented by appropriately selecting the drive frequency of the first converter 11 or the like. This content will be described below.

Let B be the magnetic flux density generated in the middle leg portion 66 shown in FIG. 12 when the converter 10 shown in FIG. 9 is driven. At this time, if the magnetic flux density B satisfies the following equation (1), magnetic saturation in the core 65 can be prevented.

B <Bmax
A> φ / Bmax equation (1)

In the formula (1), Bmax is the saturation magnetic flux density of the core 65. Bmax is a value corresponding to the magnetic characteristics of the core 65. That is, Bmax is a value corresponding to the magnetic material constituting the core 65. A is the cross-sectional area of the middle leg portion 66 shown in FIG. The magnetic flux φ is the magnetic flux φ generated in the middle leg portion 66 when the converter 10 shown in FIG. 9 is driven.

式（２）において、Ｖは、図９に示すコンバータ１０が駆動するときに、コア６５に印加される電圧である。ｎは、図９に示す巻線８０の巻き数である。Ｄは、図９に示すスイッシング素子Ｑ１Ａ～Ｑ４Ａをオンオフさせるパルス波（駆動信号）のデューティである。Ｄは、図９に示すコンバータ１０のような双方向式では、０．５であってよい。Ｔは、図９に示すスイッシング素子Ｑ１Ａ～Ｑ４Ａをオンオフさせるパルス波（駆動信号）の周期である。Ｔは、ＰＷＭ（Pulse Wide Modulation）周期ともいう。ｆは、駆動周波数である。つまり、Ｔ＝１／ｆである。 Here, the magnetic flux φ is calculated by the following equations (2) and (3).

In equation (2), V is the voltage applied to the core 65 when the converter 10 shown in FIG. 9 is driven. n is the number of turns of the winding 80 shown in FIG. D is the duty of the pulse wave (drive signal) for turning on / off the swishing elements Q1A to Q4A shown in FIG. D may be 0.5 in a bidirectional system such as the converter 10 shown in FIG. T is a period of a pulse wave (drive signal) that turns on and off the swishing elements Q1A to Q4A shown in FIG. T is also referred to as a PWM (Pulse Wide Modulation) cycle. f is a drive frequency. That is, T = 1 / f.

From the above equations (2) and (3), the magnetic flux density B in the equation (1) can be the largest when the converter 10 having the largest V is driven. In the configuration shown in FIG. 1, among the first converter 11, the second converter 12, the third converter 13, and the fourth converter 14, V can be the largest when the first converter 11 is driven.

Therefore, the drive frequency of the first converter 11 is set to be higher than the drive frequency of the second converter 12, the third converter 13, and the fourth converter 14. Further, the drive frequency of the first converter 11 is set so as to satisfy the equation (1). In other words, the drive frequency f of the first converter 11 is determined according to the magnetic characteristics of the core 65. With such a configuration, magnetic saturation in the core 65 can be prevented. Further, by driving the second converter 12, the third converter 13, and the fourth converter 14 at a drive frequency lower than the drive frequency of the first converter 11, the power conversion efficiency of the second converter 12 and the like can be improved. can.

[Controller processing]
In the second embodiment, the controller 41 shown in FIG. 1 controls the switches 91A to 94A and 91B to 94B, and the first converter 11, the second converter 12, the third converter 13 and the fourth converter 14 are not driven at the same time. To control.

For example, it is assumed that the controller 41 shown in FIG. 1 drives the first converter 11 among the first converter 11, the second converter 12, the third converter 13, and the fourth converter 14. At this time, the controller 41 controls so as not to drive the second converter 12, the third converter 13, and the fourth converter 14. In this case, the controller 41 shown in FIG. 1 outputs a control signal to the drive circuit 50 shown in FIG. 9 of the first converter 11 so that the switches 91A and 91B are turned on. Further, the controller 41 outputs a control signal to the drive circuit 50 shown in FIG. 9 of each of the second converter 12, the third converter 13, and the fourth converter 14 so that the switches 92A to 94A and 92B to 94B are turned off. do. By such control, in the first converter 11, the transformer 61 is connected to other components such as the smoothing capacitor 52A. Further, by such control, the transformers 62 to 64 are separated from other components in the second converter 12, the third converter 13, and the fourth converter 14. This makes it possible to prevent unintended current from leaking from the transformers 62 to 64 to other components in the second converter 12, the third converter 13, and the fourth converter 14 that are not driven.

The configuration in which the switches 90A and 90B are provided is not limited to the configuration shown in FIG. For example, the configuration may be as shown in FIG.

[Other circuit configurations of DC-DC converter]
FIG. 13 is a circuit diagram of a DC-DC converter according to another example of the second embodiment. FIG. 13 shows a part of the configuration shown in FIG. Similar DC-DC converters can be adopted as the first converter 11a, the second converter 12a, the third converter 13a, and the fourth converter 14a. Hereinafter, the first converter 11a will be described as an example.

The first converter 11a has switches 121A and 122A between the winding 71 and the switching circuit 51A. The first converter 11a has switches 121B and 122B between the winding 81 and the switching circuit 51B.

The switches 121A and 122A may be configured to include a relay circuit. The switch 121A is provided between one end of the winding 71 and the source of the switching element Q1A of the switching circuit 51A shown in FIG. 9 and the drain of the switching element Q2A. The switch 122A is provided between the other end of the winding 71 and the source of the switching element Q3A of the switching circuit 51A shown in FIG. 9 and the drain of the switching element Q4A.

The switches 121A and 122A switch between conduction and cutoff based on the control signal from the controller 41 shown in FIG.

The switches 121B and 122B may be configured to include a relay circuit. The switch 121B is provided between one end of the winding 81 and the source of the switching element Q1B and the drain of the switching element Q2B of the switching circuit 51B shown in FIG. The switch 122B is provided between the other end of the winding 81 and the source of the switching element Q3B and the drain of the switching element Q4B of the switching circuit 51B shown in FIG.

The switches 121B and 122B switch between conduction and cutoff based on the control signal from the controller 41 shown in FIG.

Although one embodiment according to the present disclosure has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications or modifications based on the present disclosure. It should be noted, therefore, that these modifications or modifications are within the scope of this disclosure. For example, the functions and the like included in each means can be rearranged so as not to be logically inconsistent, and a plurality of means and the like can be combined or divided into one.

For example, in the above-mentioned second embodiment, it has been described that the transformers 61 to 64 share the core 65 as shown in FIGS. 11 and 12. However, when the power supply system 1 shown in FIG. 1 does not include the fourth converter 14, the transformers 61 to 63 may be configured to share the core 65.

1 Power supply system 2 AC power supply 10 Converter 11, 11a 1st converter 12, 12a 2nd converter 13, 13a 3rd converter 14, 14a 4th converter 15 Rectifier circuit 20A, 20B Battery 21 1st battery 22 2nd battery 23 3rd Battery 31 Motor (load)
32 Auxiliary equipment (load)
33 ECU (load)
40 Memory 41 Controller 50 Drive circuit 51A, 51B Switching circuit 52A, 52B Smoothing capacitor 60, 61-64 Transformer 65 Core 66 Middle leg 66a Gap 67-1, 67-2 Side leg 68 Top 69 Bottom surface 70-74 , 80-84 Winding 90A-94A, 90B-94B Switch 100 Planer type transformer 110-117 Board 121A, 121B, 122A, 122B Switch P1-P10 Path Q1A-Q4A, Q1B-Q4B Switching element

Claims (12)

Multiple converters connected in a loop and capable of bidirectional power conversion,
In the plurality of converters, a plurality of batteries provided between adjacent converters and
With a controller that can control the multiple converters,
Equipped with
The plurality of batteries are
With the first battery
A second battery whose nominal voltage is lower than that of the first battery,
Includes a third battery, which has a lower nominal voltage than the second battery.
The plurality of converters
A first converter capable of bidirectional power conversion between the first battery and the second battery,
A second converter capable of bidirectional power conversion between the second battery and the third battery,
A power supply system comprising a third converter capable of bidirectional power conversion between the third battery and the first battery . In the power supply system according to claim 1 ,
The controller controls the first converter and the third converter to supply the electric power charged in the first battery to the second battery and the third battery. In the power supply system according to claim 2 ,
The controller can detect the abnormality of the first battery, and the controller can detect the abnormality of the first battery.
When the controller detects an abnormality in the first battery, the controller controls the first converter to supply electric power charged in the second battery to a load connected to the first battery. In the power supply system according to claim 2 ,
The controller can detect an abnormality of the second battery, and the controller can detect the abnormality of the second battery.
When the controller detects an abnormality in the second battery, the controller controls the first converter to supply electric power charged in the first battery to a load connected to the second battery. In the power supply system according to claim 2 ,
The controller can detect an abnormality of the third battery, and the controller can detect the abnormality of the third battery.
When the controller detects an abnormality in the third battery, the controller controls the third converter to supply electric power charged in the first battery to a load connected to the third battery. In the power supply system according to claim 2 ,
The controller can detect an abnormality in the first converter, and can detect an abnormality in the first converter.
When the controller detects an abnormality in the first converter, it controls the second converter and the third converter to supply the electric power charged in the first battery to the second battery and the third battery. Power system. In the power supply system according to claim 2 ,
The controller can detect an abnormality of the third converter, and can detect an abnormality of the third converter.
When the controller detects an abnormality in the third converter, it controls the first converter and the second converter to supply the electric power charged in the first battery to the second battery and the third battery. Power system. In the power supply system according to any one of claims 1 to 7 .
A power supply system in which each transformer of the first converter, the second converter, and the third converter shares a core. In the power supply system according to claim 8 ,
The transformers of the first converter, the second converter, and the third converter are planar transformers, which are power supply systems. In the power supply system according to claim 8 or 9 .
The drive frequency of the first converter is higher than the drive frequencies of the second converter and the third converter.
A power supply system in which the drive frequency of the first converter is determined according to the magnetic characteristics of the core. In the power supply system according to claim 8 or 9 .
A power supply system in which at least a switch for disconnecting the transformer from other components is provided in each of the first converter, the second converter, and the third converter. In the power supply system according to claim 11 ,
The controller is a power supply system that controls the switch in the non-controlled converters of the first converter, the second converter, and the third converter to disconnect at least the transformer from other components.

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