JPWO2018147047A1 - Control system, moving body, and control method - Google Patents

Abstract

The control system includes: a power source; a first switch; a closed circuit that electrically connects the load in series; a power storage unit connected in parallel to the load; and a state of the first switch is the first switch And a protection unit that suppresses an overvoltage state in which a voltage applied to the first switch exceeds an allowable voltage of the first switch. The protection unit suppresses the first switch from being in an overvoltage state by adjusting the operating state of the load when the first switch is in an open state.

Description

The present invention relates to a control system, a moving body, and a control method.
This application claims priority based on the Japan patent application 2017-023374 for which it applied on February 10, 2017, and uses the content here.

  In recent years, a technique for electrically driving a moving body is known (for example, see Patent Document 1). Such a mobile body includes a power storage unit, and it is necessary to efficiently obtain power from electric power stored in the power storage unit. Patent Document 1 discloses an electric circuit in which a plurality of power storage units are connected in series. By forming a power supply in which a plurality of storage batteries are connected in series, a voltage higher than that of a single storage battery can be obtained with the total value of the voltages of the storage batteries as the power supply voltage.

  As an example of a storage battery, there is a storage battery including a storage battery body and a protection switch (switch) that switches a connection state between the storage battery body and a terminal of the storage battery. The rating of the storage battery protection switch is determined based on the voltage of the storage battery body. For example, the allowable voltage in the open state of the protection switch is determined to be a voltage higher than the voltage of the storage battery body.

Japanese Unexamined Patent Publication No. 2012-34515

However, when a plurality of storage batteries containing such protection switches are connected in series to form a power supply, the power supply voltage of the power supply exceeds the allowable voltage of the protection switch of each storage battery forming the power supply. There is a case.
An aspect of the present invention is to provide a control system, a moving body, and a control method that can further improve the reliability of a switch in a closed circuit in which a power source, a switch, and a load are connected in series. To do.

  A control system according to one aspect of the present invention includes a power source, a first switch, a closed circuit that electrically connects a load in series; a power storage unit that is connected in parallel to the load; And a protection unit that suppresses a voltage applied to the first switch from becoming an overvoltage state exceeding an allowable voltage of the first switch, wherein the protection unit is in a state in which the first switch is in an open state. In this case, the first switch is prevented from entering the overvoltage state by adjusting the operating state of the load.

  In the control system, the load includes a drive unit that drives the electric motor, and the protection unit cuts off power supply from the drive unit to the electric motor when the first switch is in the open state. By controlling to, the first switch may be prevented from entering the overvoltage state.

  In the control system, the protection unit may detect an open state of the first switch based on a voltage of the power storage unit and suppress the first switch from being in the overvoltage state.

  The control system includes a second switch connected in series to the power source, the first switch, and the load in the closed circuit, and the protection unit has the first switch in the open state. In this case, the first switch may be prevented from entering the overvoltage state by opening the second switch.

  In the control system, when the first switch is in the open state, the protection unit limits the power consumption of the load, and then opens the second switch to open the first switch. May suppress the overvoltage state.

  In the control system, the power source may include a plurality of batteries connected in series, and the second switch may be provided in the closed circuit including the plurality of batteries.

  In the control system, an allowable voltage of the first switch in the open state may be smaller than a voltage value of the power source.

  A moving body according to another aspect of the present invention includes a power source, a first switch, a closed circuit that electrically connects a load in series; a power storage unit that is connected in parallel to the load; and the first A protection unit that suppresses an overvoltage state in which a voltage applied to the first switch exceeds an allowable voltage of the first switch, wherein the protection unit includes the first switch. In the open state, the first switch is prevented from entering the overvoltage state by adjusting the operating state of the load.

  A control method according to still another aspect of the present invention includes a closed circuit that electrically connects a power source, a first switch, and a load in series; and a power storage unit that is connected in parallel to the load. In the control method, when the first switch is in an open state, the operating state of the load is adjusted so that the voltage applied to the first switch is the voltage applied to the first switch. Including suppressing an overvoltage state exceeding an allowable voltage of the first switch.

  According to the above configuration, the control system includes a power source, a first switch, a closed circuit that electrically connects the load in series; a power storage unit that is connected in parallel to the load; and a state of the first switch A protection unit that suppresses an overvoltage state in which a voltage applied to the first switch exceeds an allowable voltage of the first switch; and the protection unit opens the first switch. In such a case, the operation state of the load is adjusted to prevent the first switch from entering the overvoltage state. Thereby, the protection unit can suppress the overvoltage state of the first switch, and a control system, a moving body, and a control method that can further improve the reliability of the first switch can be provided.

It is a figure showing an example of a saddle-ride type electric vehicle to which the electric circuit of the first embodiment is applied. It is a block diagram showing a schematic configuration of a control system for controlling the traveling of the electric motorcycle of the present embodiment. It is a figure for demonstrating operation | movement when the process for avoiding the influence of the sudden event of embodiment is implemented. It is a flowchart of the process for avoiding the influence of the sudden event of embodiment.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are viewed in the direction of the reference numerals, and the left and right and front and rear directions mean directions viewed from the driver.

  FIG. 1 is a diagram illustrating an example of a saddle-ride type electric vehicle to which the electric circuit of the embodiment is applied. FIG. 1 shows an example of a scooter-type saddle-ride type electric vehicle (hereinafter referred to as “electric motorcycle”) having a low floor. The electric motorcycle 1 shown in FIG. 1 is an example of a moving body. The body frame F of the electric motorcycle 1 supports the front fork 11 so that it can be steered. A front wheel WF is pivotally supported at the lower end of the front fork 11. A steering handle 16 is connected to the upper portion of the front fork 11.

A front end portion of the swing arm 17 is supported at the rear portion of the vehicle body frame F so as to be swingable.
An electric motor 135 (electric motor) is provided at the rear end of the swing arm 17. The rear wheel WR is rotationally driven by the power output from the electric motor 135.

  A pair of left and right seat frames 15 are provided so as to be connected to the rear portion of the vehicle body frame F. A riding seat 21 is supported on the seat frame 15. A synthetic resin vehicle body cover 22 that covers the vehicle body frame F is attached to the vehicle body frame F.

  FIG. 1 shows an example of arrangement of some electrical components. For example, a battery housing part 120 </ b> C made of synthetic resin is provided between the pair of left and right seat frames 15 below the riding seat 21. The battery 120 is detachably stored in the battery storage unit 120C.

  In the electric motorcycle 1, the electric motor 135 provided in the swing arm 17 is driven by a PDU (Power Driver Unit) 130 by the electric power supplied from the battery 120 via the electric circuit 110, and the electric motor 135 is driven. Travels by transmitting the rotational power at the time to the rear wheel WR. For example, the battery 120 of the embodiment is divided into a plurality of battery units such as batteries 121 and 122. The traveling of the electric motorcycle 1 is controlled by, for example, an ECU (Electric Control Unit) 140 disposed at an appropriate position such as the inside of the vehicle body cover 22. The charger 150 converts electric power supplied from the outside, and charges the battery 120 via the electric circuit 110. The charger 150 may be detachable from the electric motorcycle 1.

  FIG. 2 is a block diagram showing a schematic configuration of a control system for controlling the traveling of the electric motorcycle 1 of the present embodiment.

The control system 10 includes an electric circuit 110 (closed circuit), a battery 120, a PDU 130 (load), an ECU 140 (protection unit), and a charger 150.
The electric circuit 110 electrically connects the battery 120 (power source and first switch), the contactor 115 (first contactor), and the PDU 130 in series.

  The PDU 130 includes an inverter 131, a capacitor 133 (power storage unit), and a voltage detection unit 134. Based on the control of the ECU 140, the inverter 131 converts the DC power supplied from the battery 120 into, for example, three-phase AC power. The capacitor 133 reduces voltage fluctuation due to mechanical load fluctuation of the electric motor 135 and smoothes the voltage. The voltage detector 134 detects the voltage on the power source side of the PDU 130. The electric motor 135 is, for example, a three-phase AC motor.

  The battery 120 includes, for example, batteries 121 and 122. The batteries 121 and 122 are an example of a plurality of power storage units. The battery 120 generates a predetermined voltage (for example, its nominal voltage is 48V) by connecting a plurality of single batteries such as lithium ion batteries, nickel metal hydride batteries, and lead batteries in series.

  The electric power from the batteries 121 and 122 is supplied to the PDU 130 that drives the electric motor 135 via the electric circuit 110, and is converted from direct current to three-phase alternating current by the inverter 131 of the PDU 130 and supplied to the electric motor 135, for example. The

  For example, the output voltages of the batteries 121 and 122 are stepped down to a low voltage (for example, 12V) by a DC-DC converter (not shown) and supplied to control system components such as the ECU 140. For example, the output voltage of the battery 121 may be allowed to vary in a normal state from an upper limit voltage that is 125% of the nominal voltage of the battery 121 to a lower limit voltage that is 90% of the nominal voltage of the battery 121. For example, the output voltage of battery 122 may be allowed to vary in normal time from an upper limit voltage that is 125% of the nominal voltage of battery 122 to a lower limit voltage that is 90% of the nominal voltage of battery 122.

  Further, a part of the low-voltage power stepped down by the DC-DC converter is supplied to a general electric component such as a control battery 125 (not shown) or a lighting device (not shown).

  The batteries 121 and 122 can be charged by, for example, a charger 150 connected to an AC 100V power source.

The battery 121 of the embodiment includes a battery main body 1211, a BMU (Battery Managing Unit) 1212, a switch 1213, a high potential side terminal 121P (first pole terminal), and a low potential side terminal 121N (second pole terminal). Is provided. Similarly, the battery 122 includes a battery main body 1221, a BMU 1222, and a switch 1223. In the following description, the BMU 1212 and the BMU 1222 may be simply referred to as a BMU. The state of charge / discharge of the batteries 121 and 122, the amount of electricity stored, the temperature, and the like are monitored by the BMU of each battery. Information of the monitored batteries 121 and 122 is shared with the ECU 140. The BMU limits charging / discharging of the battery main body 1211 and the like by controlling the switch 1213 and the like based on a control command from the ECU 140 described later or the above monitoring result. Details of the switch 1213 will be described later. BMU 1212 communicates with ECU 140 via a connector (not shown). The BMU 1212 is supplied with control power through the connector.
The battery 122 is the same as the battery 121. Note that the switches 1213 and 1223 may be semiconductor elements such as FETs.

  The ECU 140 receives output request information from the throttle (accelerator) sensor 180. The ECU 140 controls the contactor 115, the battery 120, the PDU 130, and the like based on the input output request information. For example, ECU 140 can regulate charging / discharging of battery 120 by controlling battery 120. ECU 140 controls contactor 115 to switch between supply of electric power to battery 120 and discharge from battery 120. The ECU 140 controls the driving of the electric motor 135 by controlling the power supplied from the PDU 130 to the electric motor 135. In the block diagram shown in FIG. 2, the charger 150 is also included in the control system 10 that controls the running of the electric motorcycle 1, but the charger 150 is configured to be detachable from the electric motorcycle 1. Also good. In this case, the charger 150 may be provided outside the electric motorcycle 1. Note that a general method may be selected as a method of charging by the charger 150.

  The contactor 115 (second switch) is provided between the low potential side terminal 121N of the battery 121 and the high potential side terminal 122P of the battery 122. The contactor 115 connects and disconnects the low potential side terminal 121N of the battery 121 and the high potential side terminal 122P of the battery 122. Contactor 115 connects batteries 120 in series in a conductive state. Contactor 115 cancels the serial connection of battery 120 in a disconnected state. The period in which the contactor 115 is in the cut-off state includes at least a period in which the charger 150 supplies power to the battery 120.

  Note that the allowable voltage of the contactor 115 when the contactor 115 is in an open state is set sufficiently larger than the voltage of the battery 120, and is at least larger than the upper limit value (maximum voltage value) of the voltage fluctuation range of the battery 120. Let it be big.

[Example of electrical circuit drive system connection configuration]
The battery 120 of the drive system of the electric circuit 110, the contactor 115, and the PDU 130 are electrically connected in series by the electric circuit 110. As described above, the battery 120 includes the battery 121 and the battery 122, and the battery 121 and the battery 122 can be connected in series. The battery 121 includes a battery main body 1211 and a switch 1213. The battery 122 includes a battery main body 1221 and a switch 1223.

  A set of the battery main body 1211 and the battery main body 1221 is an example of a power source. The switch 1213 or the switch 1223 is an example of a first switch. The PDU 130 is an example of a load. The electric circuit 110 electrically connects the battery 120, the contactor 115, and the PDU 130 in series. That is, the electric circuit 110 electrically connects the battery main body 1211 and the battery main body 1221, the switch 1213 or the switch 1223, the contactor 115, and the PDU 130 in series. A capacitor 133 and a voltage detector 134 are connected in parallel to the power line of the PDU 130.

[Electric circuit action]
ECU 140 acquires the state of battery 120 from the BMU of battery 120. The ECU 140 acquires the voltage on the power source side of the PDU 130 from the voltage detection unit 134 of the PDU 130. The ECU 140 detects a user operation from the throttle sensor 180 or the like. For example, the ECU 140 controls the contactor 115 and the PDU 130 based on the collected information.

  For example, the ECU 140 performs processing for charging the battery 120 with the electric power of the charger 150 using the external charger 150 or the like. Moreover, ECU140 detects a user's operation and implements the process which precharges the capacitor | condenser 133 by supplying electric power to PDU130 in order to drive the electric motorcycle 1 according to a user's request | requirement. Further, the ECU 140 performs processing for driving the electric motorcycle 1 by driving the PDU 130 in accordance with a user operation. These processes may be performed according to a general procedure.

The ECU 140 according to the embodiment further executes “processing for a sudden event occurring while the electric motorcycle 1 is operating”.
The sudden event in the present embodiment refers to an operation performed to protect the configuration, an operation performed to maintain a safe state, etc. in a state where the electric motor 135 is driven by the drive unit 130. It is an event that has resulted in a result different from the result of the process requested by the user as a result of the execution of each functional unit.

A more specific example will be described.
For example, the switch 1213 or the switch 1223 of the battery 120 is not controlled to be cut off by the processing of the ECU 140 during the above control, but is controlled by the processing of the BMU in the battery 120 or the like. In other words, an event in which the switch 1213 or the switch 1223 is shut off during the above control is included in the sudden event.

[Effect of sudden event]
When the above sudden event occurs while power is being supplied to the PDU 130 and either the switch 1213 or the switch 1223 is cut off, the supply of power from the battery 120 to the PDU 130 is stopped.

  On the other hand, the ECU 140 continues to supply a control signal for driving the electric motor 135 to the PDU 130 while the state in which the occurrence of the sudden event cannot be detected continues. Since no power is supplied from the battery 120, the PDU 130 consumes the electric power stored in the capacitor and continues to drive the electric motor 135. However, when the amount of power stored in the capacitor is depleted, the electric motor 135 cannot be driven. (First effect).

  In the embodiment, the allowable voltage of the switch 1213 or the switch 1223 of the battery 120 is smaller than the power supply voltage of the battery 120. When the above sudden event occurs, the voltage applied to the switch 1213 switch 1223 may exceed the allowable voltage of the switch 1213, or the voltage applied to the switch 1223 may exceed the allowable voltage of the switch 1223 ( Second influence). This second influence may lead to a situation where the electric motorcycle 1 cannot travel. It is necessary to avoid the second effect so that this situation does not occur.

[About avoiding the effects of sudden events]
The electrical circuit 10 according to the embodiment avoids the above-described influence by performing the following processing. The details will be described below.

  FIG. 3 is a diagram for explaining an operation when processing for avoiding the influence of the sudden event according to the embodiment is performed. This figure shows a change in the voltage Vin (V) of the capacitor 133 after the sudden event occurs.

FIG. 4 is a flowchart of a process for avoiding the influence of the sudden event according to the embodiment.
First, at time t1, a sudden event occurs in which the switch 1213 or the switch 1223 of the battery 120 is cut off (SA0). As a result, the voltage of the capacitor 133 starts to decrease, but the drive of the electric motor 135 continues (SA1).

  Next, it is determined whether or not the voltage of the capacitor 133 has decreased below a predetermined threshold TH (SA2). When the voltage of the capacitor 133 has not decreased below the threshold value TH, the ECU 140 returns the process to SA1.

  Next, when the voltage of the capacitor 133 falls below the threshold value TH, the ECU 140 controls the PDU 130 to stop supplying current to the electric motor 135 (SA3). That is, at time t3, all FETs as semiconductor switches included in the PDU 130 are turned off. Thereby, the electric current which flows on the electric circuit 110 in the direction which supplies electric power with respect to the electric motor 135 is interrupted | blocked at two places.

  Next, after a predetermined time has elapsed from time t3, ECU 140 places contactor 115 in a disconnected state (SA4). Thereby, at time t5, the electric circuit 110 is interrupted at at least two places, and the voltage applied to the switch 1213 or the switch 1223 disappears, thereby avoiding the occurrence of the second influence.

A supplementary explanation of the above processing will be provided.
When the voltage of the capacitor 133 is consumed by the load (electric motor 135), the voltage of the battery 120 is maintained as it is, and only the voltage of the capacitor 133 decreases. Therefore, the potential difference between the voltage of the battery 120 and the voltage of the capacitor 133 is applied to the switch (switch 1213 or switch 1223) that is cut off due to the sudden event. If this voltage exceeds the allowable voltage of the switch, the switch may be destroyed.

  On the other hand, an embodiment in which another switch (switch) is arranged in the closed circuit of the electric circuit 10 in addition to the above-described switch, and the switch is quickly disconnected when a sudden event occurs (implementation) Example 1). When the method of the first embodiment is realized by a mechanical switch (switch), the time required for circuit disconnection is expected to take about 100 milliseconds.

  Instead of the mechanical switch (switch) of the first embodiment, a countermeasure realized by an electric switch can be considered (second embodiment). In this case, there is no time delay depending on mechanical elements, and the time required for circuit disconnection can be shortened, which is preferable from the viewpoint of shortening the response time. By using the electric switch, for example, even when the electric charge of the capacitor 133 is consumed in about 10 milliseconds, it is possible to perform processing for suppressing consumption in the process.

  However, when a mechanical switch as a main switch is provided in the electric circuit 110, it is necessary to additionally provide an electric switch. Therefore, in this embodiment, the control of the PDU 130 is combined in order to ensure responsiveness without adding an electric switch.

  The PDU 130 includes an inverter 131 for driving the electric motor 135, that is, a semiconductor switch. The PDU 130 uses this semiconductor switch to cut off the current of the electric circuit 110 when a predetermined condition is satisfied.

  According to the embodiment, the control system includes a main body of the battery 120, a switch (first switch) in the battery 120, a closed circuit that electrically connects the PDU 130 in series, and a capacitor that is connected in parallel to the PDU 130. 133 and an ECU 140 (protection unit) that suppresses that the state of the first switch is an overvoltage state in which the voltage applied to the first switch exceeds the allowable voltage of the first switch. The EUC 140 suppresses the first switch from entering an overvoltage state by adjusting the operating state of the PDU 130 and limiting the power consumption when the first switch is in an open state. The reliability of the switch can be further increased.

  The overvoltage state of the first switch is a state where the voltage applied to the first switch exceeds the allowable voltage of the first switch. The allowable voltage of the first switch is the maximum allowable inter-terminal voltage in the open state. The open state of the first switch includes a state after transition from the conductive state in which the electric circuit 10 is energized to the open state.

  Note that the above-described overvoltage state is included in a state where the voltage of the capacitor 133 is lowered to a desired voltage (power supply voltage) or less. More specifically, the above-described overvoltage state is included in a state in which the voltage of the capacitor 133 has dropped below the single voltage of the battery 121 or the battery 122.

  The load of the capacitor 133 includes an electric motor 135 and a PDU 130 (driving unit) that drives the electric motor 135. The ECU 140 may suppress the first switch from being in an overvoltage state by controlling the power supply from the PDU 130 to the electric motor 135 when the first switch is in an open state.

  Further, the ECU 140 may suppress the first switch from being in an overvoltage state by detecting the open state of the first switch based on the voltage of the capacitor 133.

  In addition, the control system 10 includes, in the electric circuit 110, a main body of the battery 120, a switch (first switch) in the battery 120, and a contactor 115 (second switch) connected in series to the PDU 130. The ECU 140 may suppress the first switch from being in an overvoltage state by opening the contactor 115 when the first switch is in an open state.

  Further, the ECU 140 may prevent the first switch from being overvoltaged by opening the contactor 115 after limiting the power consumption of the PDU 130 when the first switch is opened. Good.

Battery 120 includes a plurality of battery bodies connected in series as a power source.
The contactor 115 is provided in the electric circuit 110 including a plurality of battery main bodies, and the electric circuit 110 may be opened under the control of the ECU 140 to suppress the first switch from being in an overvoltage state.

  Further, the allowable voltage of the first switch in the open state may be smaller than the voltage value of the power source.

  The ECU 140 according to the embodiment includes a computer system. ECU140 records the program for implement | achieving said process on a computer-readable recording medium, makes a computer system read the program recorded on the recording medium, and performs it, and performs various processes mentioned above. You may go. Here, the “computer system” may include an OS and hardware such as peripheral devices. The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

  Further, the “computer-readable recording medium” refers to a volatile memory (for example, DRAM (Dynamic) in a computer system serving as a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. Random Access Memory)) that holds a program for a certain period of time is also included. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  As mentioned above, although embodiment of this invention was described using drawing, this invention is not limited to such embodiment at all, and various deformation | transformation and substitution may be added within the range which does not deviate from the summary of this invention. it can.

1 ... Electric motorcycle (moving body)
10 ... Control system 110 ... Electric circuit (closed circuit)
115 ... Contactor (second switch)
120, 121, 122 ... battery 120C ... battery storage unit 130 ... PDU (load)
133: Capacitor (power storage unit)
135: Electric motor 140: ECU (protection unit)
150 ... chargers 1211, 1221 ... battery body (power supply)
1212, 1222 ... BMU
1213, 1223... Switch (first switch).

Claims (9)

A closed circuit that electrically connects the power source, the first switch, and the load in series;
A power storage unit connected in parallel to the load;
A protection unit that prevents the state of the first switch from becoming an overvoltage state in which a voltage applied to the first switch exceeds an allowable voltage of the first switch;
With
The protection unit suppresses the first switch from being in the overvoltage state by adjusting the operating state of the load when the first switch is in an open state.
Control system. The load includes a drive unit that drives an electric motor,
The protection unit controls the first switch to be in the overvoltage state by controlling the power supply from the drive unit to the motor when the first switch is in the open state. Suppress,
The control system according to claim 1. The protection unit detects an open state of the first switch based on a voltage of the power storage unit, and suppresses the first switch from being in the overvoltage state.
The control system according to claim 1 or claim 2. A second switch connected in series to the power source, the first switch, and the load in the closed circuit;
The protection unit suppresses the first switch from entering the overvoltage state by opening the second switch when the first switch is in the open state.
The control system according to claim 1 or claim 2. When the first switch is in the open state, the protection unit limits the power consumption of the load and then opens the second switch so that the first switch is in the overvoltage state. To suppress,
The control system according to claim 4. The power source includes a plurality of batteries connected in series,
The second switch is provided in the closed circuit including the plurality of batteries.
The control system according to claim 4 or 5. An allowable voltage of the first switch in the open state is smaller than a voltage value of the power source;
The control system according to any one of claims 1 to 6. A closed circuit that electrically connects the power source, the first switch, and the load in series;
A power storage unit connected in parallel to the load;
A protection unit that prevents the state of the first switch from becoming an overvoltage state in which a voltage applied to the first switch exceeds an allowable voltage of the first switch;
With
The said protection part is a mobile body which suppresses that a said 1st switch will be in the said overvoltage state by adjusting the operating state of the said load, when the said 1st switch will be in an open state. A closed circuit that electrically connects a power source, a first switch, and a load in series; and a power storage unit that is connected in parallel to the load;
By adjusting the operating state of the load when the first switch is in an open state, the state of the first switch is such that the voltage applied to the first switch becomes the allowable voltage of the first switch. The control method including suppressing becoming the overvoltage state which exceeded.

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