Charger, charge system, and control method

Abstract

To simplify a configuration related to charging when charging electricity using a DC power supply.SOLUTION: A charger for charging a battery from a direct-current power supply comprises: a motor having a multiple winding; a first inverter connected between one winding of the multiple winding and the battery, for converting inputted direct-current power into alternating-current power and outputting the converted power to the motor; a second inverter connected between the other winding of the multiple winding and the battery, for converting inputted direct-current power into alternating-current power and outputting the converted power to the motor; a first relay switch connected between the battery and the second inverter, for opening / closing between contacts by an external directive; a second relay switch connected between the direct-current power supply and the second inverter, for opening / closing between contacts by an external directive; and a control unit that, when charging the battery with electricity from the direct-current power supply, outputs a drive signal for opening the contacts of the first relay switch as the external directive, and outputs a drive signal for closing the contacts of the second relay switch as the external directive.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a charging device, a charging system, and a control method.

Background Art

[0002] As methods for charging a battery mounted on an electric vehicle, there are a normal charging method and a rapid charging method. In the normal charging method, an AC power supply system is connected to the charging port of the electric vehicle, and is converted into DC power by a dedicated on-vehicle charger (OBC: On Board Charger) mounted on the electric vehicle to charge the battery. In the rapid charging method, a charging device installed in a charging stand or the like converts AC power into DC power and outputs it. The output system from this charging device is connected to the charging port of the electric vehicle to charge the battery.

[0003] In recent years, by replacing a part of the functions of the on-vehicle charger with a drive motor and an inverter mounted on an electric vehicle, a technology has been developed to simplify the dedicated on-vehicle charger and make the electric vehicle lightweight and low-cost. For example, Patent Document 1 discloses a charging device that includes a first inverter and a second inverter that drive a dual three-phase motor, and a converter that converts power from an AC power supply system into DC power and supplies it to the second inverter. When charging the battery from the AC power supply system, the dual three-phase motor is used as an isolation transformer and functions as an isolation type DC-DC converter together with the first inverter and the second inverter, thereby omitting the insulation part in the on-vehicle charger (OBC).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the charging device disclosed in Patent Document 1 is configured to be connected to an AC power supply system, it has not been possible to connect and charge a DC power source such as solar power generation, which has been increasingly popular in recent years, to the charging port. Therefore, in order to perform charging using a DC power source, a separate charging device having an insulated power conversion unit is required, and there has been a problem that the charging system becomes large. Further, in charging using a separate charging device, sequence control by communication is required between the battery control unit in the electric vehicle and the charging control unit in the charging device, and there has been a problem that charging cannot be performed if a communication abnormality occurs due to the compatibility between the devices.

[0006] The present disclosure has been made in view of the above circumstances, and one of the objectives is to provide a charging device, a charging system, and a control method that simplify the configuration related to charging when charging using a DC power source.

Means for Solving the Problems

[0007] One aspect of the present disclosure is a charging device that charges a battery with power from a DC power supply, comprising: a motor having a multi-winding; a first inverter connected between one of the multi-windings and the battery, converting the input DC power into AC power and outputting the AC power to the motor; a second inverter connected between the other of the multi-windings and the battery, converting the input DC power into AC power and outputting the AC power to the motor; a first relay switch connected between the battery and the second inverter, opening and closing the contacts between the contacts by an external command; a second relay switch connected between the DC power supply and the second inverter, opening and closing the contacts between the contacts by an external command; a battery monitoring unit for monitoring the state of the battery; and a control unit for acquiring information indicating the state of the battery from the battery monitoring unit and outputting drive signals to the first inverter, the second inverter, the first relay switch, and the second relay switch based on the acquired information indicating the state of the battery. When charging the battery with power from the DC power supply, the control unit outputs a drive signal for opening the contacts of the first relay switch as the external command to the first relay switch and outputs a drive signal for closing the contacts of the second relay switch as the external command to the second relay switch.

[0008] Also, one aspect of the present disclosure is a charging system including a battery, a DC power supply, and a charging device that charges the battery with power from the DC power supply, the charging system including: a motor having a multi-winding; a first inverter connected between one of the multi-windings and the battery, converting input DC power into AC power and outputting the AC power to the motor; a second inverter connected between the other of the multi-windings and the battery, converting input DC power into AC power and outputting the AC power to the motor; a first relay switch connected between the battery and the second inverter, opening and closing between contacts by an external command; a second relay switch connected between the DC power supply and the second inverter, opening and closing between contacts by an external command; a battery monitoring unit that monitors the state of the battery; and a control unit that acquires information indicating the state of the battery from the battery monitoring unit and outputs drive signals to the first inverter, the second inverter, the first relay switch, and the second relay switch based on the acquired information indicating the state of the battery. When charging the battery from the DC power supply, the control unit outputs, as the external command, a drive signal for opening the contacts of the first relay switch to the first relay switch and outputs, as the external command, a drive signal for closing the contacts of the second relay switch to the second relay switch.

[0009] Also, one aspect of the present disclosure includes a motor having a multi-winding, a first inverter connected between one of the multi-windings and a battery, converting the input DC power into AC power and outputting it to the motor, a second inverter connected between the other of the multi-windings and the battery, converting the input DC power into AC power and outputting it to the motor, a first relay switch connected between the battery and the second inverter, opening and closing the contacts by an external command, a second relay switch connected between a DC power supply and the second inverter, opening and closing the contacts by an external command, a battery monitoring unit for monitoring the state of the battery, and a control unit that acquires information indicating the state of the battery from the battery monitoring unit and outputs drive signals to the first inverter, the second inverter, the first relay switch, and the second relay switch based on the acquired information indicating the state of the battery. A control method for a charging device that charges the battery with power from the DC power supply, wherein when the control unit charges the battery from the DC power supply, the control unit outputs a drive signal for opening the contacts of the first relay switch as the external command to the first relay switch, and outputs a drive signal for closing the contacts of the second relay switch as the external command to the second relay switch.

Advantages of the Invention

[0010] According to the present disclosure, the configuration related to charging when connecting a DC power source to the charging port for charging can be simplified.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments will be described with reference to the drawings. <First Embodiment> [Configuration of Charging System] FIG. 1 is a schematic block diagram showing an example of the configuration of the charging system according to the present embodiment. The charging system 1 shown in FIG. 1 includes an electric vehicle 100, a single-phase AC power supply system 201 (single-phase AC power supply source), a three-phase AC power supply system 202 (three-phase AC power supply source), and a DC power bus 204 (DC power supply source) such as solar power generation.

[0013] The electric vehicle 100 includes a charging device 5, a battery 10, and inlets 111, 112, 114. The charging device 5 is an in-vehicle charging device mounted on the electric vehicle 100. The charging device 5 includes a first inverter 21, a second inverter 22, a dual three-phase motor 3 having a first winding 31 and a second winding 32, a converter 23, a filter 6, a battery controller 15, a charge and discharge controller 25, relay switches 71, 72, relay switches 412, 423, 424, and relay switches 512, 523, 524. The relay switches 71, 72, the relay switches 412, 423, 424, and the relay switches 512, 523, 524 are turned ON or OFF (the connection points are opened and closed) by an external command (for example, a drive signal from the charge and discharge controller 25).

[0014] (Connection configuration between the electric vehicle and an external power supply system) First, the configuration of the connection between the electric vehicle 100 and an external power supply system will be described. The inlets 111, 112, 114 are provided as charging ports (an example of a connection part) of the electric vehicle 100. A connector 121 is connected to the single-phase AC power supply system 201, and by connecting this connector 121 to the inlet 111, the electric vehicle 100 and the single-phase AC power supply system 201 can be connected. A connector 122 is connected to the three-phase AC power supply system 202, and by connecting this connector 122 to the inlet 112, the electric vehicle 100 and the three-phase AC power supply system 202 can be connected. A connector 124 is connected to the DC power bus 204, and by connecting this connector 124 to the inlet 114, the electric vehicle 100 and the DC power bus 204 can be connected.

[0015] (Configuration on the electric vehicle side) Next, the configuration of the charging system 1 on the electric vehicle 100 side will be described. The inlets 111 and 112 are each connected to one side of the filter 6 via the relay switches 71 and 72, respectively. The other side of the filter 6 is connected to the AC part (AC side) of the converter 23. The DC part (DC side) of the converter 23 is connected to the DC part (DC side) of the second inverter 22 via the relay switches 423 and 523.

[0016] The converter 23 is a bridge circuit that uses six IGBTs (Insulated Gate Bipolar Transistors) with diodes connected in reverse parallel as switching devices (switching elements). Each of the six IGBTs is provided in a set with an FWD (Free Wheeling Diode). The converter 23 converts the AC power input from the single-phase AC power system 201 connected to the inlet 111 via the connector 121 into DC power and outputs it to the second inverter 22. Alternatively, the converter 23 converts the AC power input from the three-phase AC power system 202 connected to the inlet 112 via the connector 122 into DC power and outputs it to the second inverter 22.

[0017] The inlet 114 is connected to the DC part (DC side) of the second inverter 22 via the relay switches 424 and 524. That is, the relay switches 424 and 524 are connected between the DC power bus 204 and the DC part (DC side) of the second inverter 22.

[0018] The first inverter 21 is a bridge circuit that uses six IGBTs as switching devices. Each of the six IGBTs is provided in a set with an FWD. In the first inverter 21, the reference numeral 21aH refers to the IGBT and FWD of the U-phase upper arm, the reference numeral 21bH refers to the IGBT and FWD of the V-phase upper arm, and the reference numeral 21cH refers to the IGBT and FWD of the W-phase upper arm. Also, in the first inverter 21, the reference numeral 21aL refers to the IGBT and FWD of the U-phase lower arm, the reference numeral 21bL refers to the IGBT and FWD of the V-phase lower arm, and the reference numeral 21cL refers to the IGBT and FWD of the W-phase lower arm.

[0019] The first inverter 21 is connected between the first winding 31 of the dual three-phase motor 3 and the battery 10. The first winding 31 of the dual three-phase motor 3 is connected to the AC part (AC side) of the first inverter 21, and the battery 10 is connected to the DC part (DC side) of the first inverter 21. The first inverter 21 converts the input DC power into AC power and outputs it to the dual three-phase motor 3.

[0020] The second inverter 22 is a bridge circuit that uses six IGBTs as switching devices. Each of the six IGBTs is provided in a set with an FWD. In the second inverter 22, the reference numeral 22aH refers to the IGBT and FWD of the U-phase upper arm, the reference numeral 22bH refers to the IGBT and FWD of the V-phase upper arm, and the reference numeral 22cH refers to the IGBT and FWD of the W-phase upper arm. Also, in the second inverter 22, the reference numeral 22aL refers to the IGBT and FWD of the U-phase lower arm, the reference numeral 22bL refers to the IGBT and FWD of the V-phase lower arm, and the reference numeral 22cL refers to the IGBT and FWD of the W-phase lower arm.

[0021] The second inverter 22 is connected between the second winding 32 of the dual three-phase motor 3 and the battery 10. The second winding 32 of the dual three-phase motor 3 is connected to the AC part (AC side) of the second inverter 22, and the battery 10 and the DC part (DC side) of the first inverter 21 are connected to the DC part (DC side) of the second inverter 22 via the relay switch 412 and the relay switch 512. That is, the relay switch 412 and the relay switch 512 are connected between the battery 10 and the DC part (DC side) of the second inverter 22. The second inverter 22 converts the input DC power into AC power and outputs it to the dual three-phase motor 3.

[0022] FIG. 2 is a diagram showing a part of the configuration of the charging system shown in FIG. 1, and is a diagram redrawn as an electrical circuit diagram of the connections between the first inverter 21, the first winding 31 and the second winding 32 of the dual three-phase motor 3, and the second inverter 22, respectively. In the dual three-phase motor 3, the first winding 31 and the second winding 32 are wound around one stator core and can be regarded as a three-phase isolation transformer. And it can be regarded that the first inverter 21 connected to the first winding 31 and the second inverter 22 connected to the second winding 32 constitute an isolated DC-DC converter circuit and operate as follows.

[0023] When the second inverter 22 converts DC power into three-phase AC power and outputs it, a three-phase AC voltage is applied to the second winding 32 of the dual three-phase motor 3, and three-phase AC power is induced in the first winding 31 magnetically coupled to the second winding 32. The induced three-phase AC power is rectified by the first inverter 21 and converted into DC power.

[0024] Returning to FIG. 1, the battery 10 is a secondary battery that stores the power supplied to the motor that is the power source of the electric vehicle 100, and is a configuration to be charged in the charging system 1. The control signal line from the battery 10 is connected to the battery controller 15. The battery controller 15 monitors the state of the battery 10 using the control signal line from the battery 10.

[0025] The control signal lines from the charge / discharge controller 25 are connected to the first inverter 21, the second inverter 22, the converter 23, the battery controller 15, the relay switches 71, 72, the relay switches 412, 423, 424, and the relay switches 512, 523, 524.

[0026] The charge / discharge controller 25 acquires state information indicating the state of the battery 10 using the control signal line from the battery controller 15, and controls the charging operation of the battery 10 based on the acquired state information of the battery 10. For example, the charge / discharge controller 25 outputs drive signals to the first inverter 21, the second inverter 22, the converter 23, the relay switches 71, 72, the relay switches 412, 423, 424, the relay switches 512, 523, 524, etc. based on the state information of the battery 10 acquired from the battery controller 15.

[0027] Also, when the charge / discharge controller 25 charges the battery 10 with the power from an external power system, it determines whether it is connected to the single-phase AC power system 201, the three-phase AC power system 202, or the DC power bus 204, and controls whether to turn on (close the contacts) or turn off (open the contacts) the relay switches 71, 72, the relay switches 412, 423, 424, and the relay switches 512, 523, 524 according to the determination result.

[0028] As an example, when the charge / discharge controller 25 charges the battery 10 with the power from the DC power supply bus 204, it outputs a drive signal to turn off the relay switches 412 and 512 to the relay switches 412 and 512, and outputs a drive signal to turn on the relay switches 424 and 524 to the relay switches 424 and 524. On the other hand, when the charge / discharge controller 25 does not charge the battery 10 with the power from the DC power supply bus 204, it outputs a drive signal to turn on the relay switches 412 and 512 to the relay switches 412 and 512, and outputs a drive signal to turn off the relay switches 424 and 524 to the relay switches 424 and 524. The processing regarding charging by such a charge / discharge controller 25 will be described in detail below.

[0029] [Operation of the Charging System] Next, the operation of the processing performed by the charge / discharge controller 25 in the charging system 1 according to the present embodiment will be described with reference to FIGS. 1 and 3. Hereinafter, a drive signal for turning on a relay switch will be referred to as an "ON signal", and a drive signal for turning off a relay switch will be referred to as an "OFF signal". Also, an operation mode in which the battery 10 is charged with the power from an external power system when the electric vehicle 100 is stopped will be referred to as a "charging mode".

[0030] FIG. 3 is a flowchart showing an example of the processing performed by the charge / discharge controller in the charging system according to the present embodiment.

[0031] (Step S101) The charge / discharge controller 25 determines whether it is in the charging mode. If the charge / discharge controller 25 determines that it is not in the charging mode (NO), it proceeds to step S103. On the other hand, if the charge / discharge controller 25 determines that it is in the charging mode (YES), it proceeds to step S105.

[0032] (Step S103) When not in the charging mode (for example, during driving), the charge / discharge controller 25 controls the opening and closing of the contacts of the relay switches as follows. The charge / discharge controller 25 outputs an OFF signal to the relay switches 423, 424, the relay switches 523, 524, and the relay switches 71, 72 to open the contacts of these relay switches. Also, the charge / discharge controller 25 outputs an ON signal to the relay switch 412 and the relay switch 512 to close the contacts of these relay switches. As a result, the DC part (DC side) of the second inverter 22 is connected only to the battery 10 and the DC part (DC side) of the first inverter 21.

[0033] The charge / discharge controller 25 outputs a gate drive signal to the first inverter 21 and the second inverter 22, causing the first inverter 21 and the second inverter 22 to output a three-phase AC current having a sine wave shape, and rotationally driving the dual three-phase motor 3.

[0034] (Step S105) If it is determined as "YES" in Step S101, the charge / discharge controller 25 determines whether the connector 121 of the single-phase AC power supply system 201 is connected to the inlet 111. When the charge / discharge controller 25 determines that the connector 121 of the single-phase AC power supply system 201 is connected to the inlet 111 (YES), it proceeds to Step S107. On the other hand, when the charge / discharge controller 25 determines that the connector 121 of the single-phase AC power supply system 201 is not connected to the inlet 111 (NO), it proceeds to Step S109.

[0035] (Step S107) The charge / discharge controller 25 controls the charging operation from the single-phase AC power supply system 201 to the battery 10. When the charge / discharge controller 25 charges the battery 10 with the power from the single-phase AC power supply system 201, it controls the opening and closing of the contacts of the relay switches as follows.

[0036] The charge and discharge controller 25 outputs an OFF signal to the relay switches 412, 424, the relay switches 512, 524, and the relay switch 72, opening the contacts of these relay switches. Also, the charge and discharge controller 25 outputs an ON signal to the relay switch 71, the relay switch 423, and the relay switch 523, closing the contacts of these relay switches. As a result, the DC part (DC side) of the second inverter is connected only to the DC part (DC side) of the converter 23. Also, the AC part (AC side) of the converter 23 is connected to the single-phase AC power system 201 via the filter 6, the relay switch 71, the inlet 111, and the connector 121.

[0037] The charge and discharge controller 25 outputs a gate drive signal to the converter 23 to control it such that the power factor of the power flowing from the single-phase AC power system 201 to the converter 23 becomes 1 and the DC voltage of the converter 23 becomes higher than the voltage of the battery 10. At this time, the AC power from the single-phase AC power system 201 is converted into DC power by the operation of the converter 23 and input to the DC part (DC side) of the second inverter.

[0038] The charge and discharge controller 25 outputs a gate drive signal to the second inverter 22 to control it such that the output current of the second inverter 22 has a current waveform in which no rotational torque is generated in the dual three-phase motor 3.

[0039] FIG. 4 is a diagram showing an example of the output current waveform of the second inverter in the charging mode according to the present embodiment. For example, as shown in FIG. 4, the charge and discharge controller 25 controls the currents of the U-phase, V-phase, and W-phase such that the magnetic field inside the dual three-phase motor 3 becomes an alternating magnetic field and no rotational torque is generated. Also, the charge and discharge controller 25 outputs a gate drive signal to the first inverter 21 to turn off all the IGBTs and operate the first inverter 21 as a rectifier circuit.

[0040] At this time, when the high-frequency AC current output by the second inverter 22 flows through the second winding 32 of the dual three-phase motor 3, the dual three-phase motor 3 operates as a current transformer (CT), and a current flows through the first winding 31 to cancel the internal magnetic flux in the iron core of the dual three-phase motor 3. This current is rectified by the first inverter 21 to charge the battery 10. Further, the charge / discharge controller 25 acquires the state information of the battery 10 from the battery controller 15, and controls the above charging operation based on the acquired state information of the battery 10.

[0041] (Step S109) When it is determined as "NO" in step S105, the charge / discharge controller 25 determines whether the connector 122 of the three-phase AC power supply system 202 is connected to the inlet 112. When the charge / discharge controller 25 determines that the connector 122 of the three-phase AC power supply system 202 is connected to the inlet 112 (YES), it proceeds to step S111. On the other hand, when the charge / discharge controller 25 determines that the connector 122 of the three-phase AC power supply system 202 is not connected to the inlet 112 (NO), it proceeds to step S113.

[0042] (Step S111) The charge / discharge controller 25 controls the charging operation of the three-phase AC power supply system 202 to the battery 10. When the charge / discharge controller 25 charges the battery 10 with the power from the three-phase AC power supply system 202, it controls the opening and closing of the contacts of the relay switch as follows.

[0043] The charge and discharge controller 25 outputs OFF signals to the relay switches 412, 424, the relay switches 512, 524, and the relay switch 71, opening the contacts of these relay switches. Further, the charge and discharge controller 25 outputs ON signals to the relay switch 72, the relay switch 423, and the relay switch 523, closing the contacts of these relay switches. As a result, the DC section (DC side) of the second inverter is connected only to the DC section (DC side) of the converter 23. Also, the AC section (AC side) of the converter 23 is connected to the three-phase AC power system 202 via the filter 6, the relay switch 72, the inlet 112, and the connector 122.

[0044] The charge and discharge controller 25 outputs a gate drive signal to the converter 23 to control it such that the power factor of the power flowing from the three-phase AC power system 202 to the converter 23 becomes 1 and the DC voltage of the converter 23 becomes higher than the voltage of the battery 10. At this time, the AC power from the three-phase AC power system 202 is converted into DC power by the operation of the converter 23 and input to the DC section (DC side) of the second inverter.

[0045] The charge and discharge controller 25 outputs a gate drive signal to the second inverter 22 to control it such that the output current of the second inverter 22 has a current waveform in which no rotational torque is generated in the dual three-phase motor 3. For example, as shown in FIG. 4, the currents of the U-phase, V-phase, and W-phase are controlled such that the magnetic field inside the dual three-phase motor 3 becomes an alternating magnetic field and the current waveform in which no rotational torque is generated. Further, the charge and discharge controller 25 outputs a gate drive signal to the first inverter 21 to turn off all the IGBTs, operating the first inverter 21 as a rectifier circuit.

[0046] At this time, when the high-frequency AC current output by the second inverter 22 flows through the second winding 32 of the dual three-phase motor 3, the dual three-phase motor 3 operates as a current transformer (CT), and a current flows through the first winding 31 to cancel the internal magnetic flux in the iron core of the dual three-phase motor 3. This current is rectified by the first inverter 21 to charge the battery 10. Further, the charge and discharge controller 25 acquires the state information of the battery 10 from the battery controller 15, and controls the above charging operation based on the acquired state information of the battery 10.

[0047] (Step S113) When it is determined as "NO" in step S109, the charge and discharge controller 25 determines whether the connector 124 of the DC power supply bus 204 is connected to the inlet 114. When the charge and discharge controller 25 determines that the connector 124 of the DC power supply bus 204 is connected to the inlet 114 (YES), it proceeds to step S115. On the other hand, when the charge and discharge controller 25 determines that the connector 124 of the DC power supply bus 204 is not connected to the inlet 114 (NO), it proceeds to step S103.

[0048] (Step S115) The charge and discharge controller 25 controls the charging operation from the DC power supply bus 204 to the battery 10. When the charge and discharge controller 25 charges the battery 10 with the power from the DC power supply bus 204, it controls the relay switch as follows.

[0049] The charge and discharge controller 25 outputs OFF signals to the relay switches 412, 423, the relay switches 512, 523, and the relay switches 71, 72 to open the contacts of these relay switches. Further, the charge and discharge controller 25 outputs ON signals to the relay switch 424 and the relay switch 524 to close the contacts of these relay switches. As a result, the DC part (DC side) of the second inverter is connected to the DC power supply bus 204 via the inlet 114 and the connector 124. That is, the DC power from the DC power supply bus 204 is input to the DC part (DC side) of the second inverter.

[0050] The charge and discharge controller 25 outputs a gate drive signal to the second inverter 22, and controls the output current of the second inverter 22 so that the current waveform does not generate rotational torque in the dual three-phase motor 3. For example, as shown in FIG. 4, the currents of the U-phase, V-phase, and W-phase are controlled so that the internal magnetic field of the dual three-phase motor 3 becomes an alternating magnetic field and the current waveform does not generate rotational torque. Further, the charge and discharge controller 25 outputs a gate drive signal to the first inverter 21 to turn off all the IGBTs, and operates the first inverter 21 as a rectifier circuit.

[0051] At this time, when the high-frequency AC current output by the second inverter 22 flows through the second winding 32 of the dual three-phase motor 3, the dual three-phase motor 3 operates as a current transformer (CT), and a current flows through the first winding 31 to cancel the internal magnetic flux in the iron core of the dual three-phase motor 3. This current is rectified by the first inverter 21 to charge the battery 10. Further, the charge and discharge controller 25 acquires the state information of the battery 10 from the battery controller 15, and controls the above charging operation based on the acquired state information of the battery 10.

[0052] As described above, the charging system 1 according to the present embodiment includes a battery 10 and a charging device 5 that charges the battery 10 with electric power from an external power supply system. For example, the charging system 1 includes a DC power supply bus 204 (DC power supply source) as an external power supply system. For example, the charging system 1 (charging device 5) includes a dual three-phase motor 3 (an example of a motor) having a first winding 31 and a second winding 32 (an example of a multi-winding), a first inverter 21, a second inverter 22, a relay switch 412 and a relay switch 512 (an example of a first relay switch), a relay switch 424 and a relay switch 524 (an example of a second relay switch), a battery controller 15 (an example of a battery monitoring unit), and a charge / discharge controller 25 (an example of a control unit). The first inverter 21 is connected between one of the first winding 31 and the second winding 32 (for example, the first winding 31) and the battery 10, converts the input DC power (DC power) into AC power (AC power), and outputs it to the dual three-phase motor 3. The second inverter 22 is connected between the other winding of the first winding 31 and the second winding 32 (for example, the second winding 32) and the battery 10, converts the input DC power into AC power, and outputs it to the dual three-phase motor 3. The relay switches 412 and 512 are connected between the battery 10 and the second inverter 22, and the contacts are opened and closed by an external command. The relay switches 424 and 524 are connected between the DC power supply bus 204 and the second inverter 22, and the contacts are opened and closed by an external command. The battery controller 15 monitors the state of the battery 10.

[0053] The charge / discharge controller 25 acquires state information indicating the state of the battery 10 from the battery controller 15, and based on the acquired state information of the battery 10, outputs drive signals to the first inverter 21, the second inverter 22, the relay switches 412 and 512, and the relay switches 424 and 524. For example, when the charge / discharge controller 25 charges the battery 10 with the power from the DC power bus 204, it outputs a drive signal (OFF signal) for opening the contacts of the relay switches 412 and 512 as the above external command to the relay switches 412 and 512, and outputs a drive signal (ON signal) for closing the contacts of the relay switches 424 and 524 as the external command to the relay switches 424 and 524.

[0054] Thereby, the charging system 1 (charging device 5) can charge the battery 10 of the electric vehicle 100 while ensuring insulation in the dual three-phase motor 3 from a DC power source such as solar power generation without an insulated power conversion unit by controlling the opening and closing of the contacts of each relay switch. For example, the charging system 1 (charging device 5) includes relay switches 412, 423, 424, 512, 523, 524, and can charge the battery 10 from the DC power bus 204 by closing the contacts of the relay switches 424 and 524 (the contacts of the other relay switches are open).

[0055] Therefore, the charging system 1 (charging device 5) can charge the battery 10 not only from an AC power supply but also using the DC power bus 204 (DC power supply). Moreover, when charging using the DC power bus 204 (DC power supply), since an insulated power conversion unit is not required in the charging device 5, the configuration of the charging device 5 and the charging system 1 can be simplified. That is, the charging system 1 (charging device 5) can simplify the configuration related to charging when charging using the DC power bus 204 (DC power supply).

[0056] In addition, since the charging system 1 (charging device 5) is configured such that the charge and discharge controller 25 controls the charging operation of the battery 10, charging control can be completed within the electric vehicle 100, and control by communication with other charging devices (such as a DC power supply) is not required. Therefore, it is possible to suppress the occurrence of problems such as being unable to charge due to communication abnormalities caused by compatibility between devices.

[0057] Also, when the charge and discharge controller 25 does not charge the battery 10 with the power from the DC power bus 204, it outputs a drive signal (ON signal) that closes the contacts of the relay switch 412 and the relay switch 512 as the above external command to the relay switch 412 and the relay switch 512, and outputs a drive signal (OFF signal) that opens the contacts of the relay switch 424 and the relay switch 524 as the above external command to the relay switch 424 and the relay switch 524.

[0058] Thereby, when the charging system 1 (charging device 5) does not charge the battery 10, it can drive the dual three-phase motor 3.

[0059] Here, when charging the battery 10 from the DC power bus 204, the waveform of the output current of the second inverter 22 is a current waveform in which no rotational torque is generated in the dual three-phase motor 3. For example, the charge and discharge controller 25 controls the current waveform of the output current of the second inverter 22 during the charging operation to be a current waveform (alternating current with coincident zero-crossing timing) in which the magnetic field inside the dual three-phase motor 3 becomes an alternating magnetic field and no rotational torque is generated, as shown in FIG. 4.

[0060] Thereby, the charging system 1 (charging device 5) can prevent the dual three-phase motor 3 from rotating when charging the battery 10, and can suppress unnecessary noise, vibration, and the like.

[0061] Note that any other control may be used as long as the control is such that the current waveform of the output current of the second inverter 22 during the charging operation is a current waveform in which no rotational torque is generated in the dual three-phase motor 3.

[0062] FIG. 5 is a diagram showing another example of the output current waveform of the second inverter in the charging mode according to the present embodiment. The charge / discharge controller 25 may control such that the current waveform of the output current of the second inverter 22 during the charging operation is a current waveform in which no rotational torque is generated in the dual three-phase motor 3 (alternating current or zero current with the same zero-crossing timing) as shown in FIG. 5.

[0063] That is, when charging the battery 10 from the DC power supply bus 204, the waveforms of the output currents of the respective phases of the second inverter 22 may be alternating currents or zero currents with the same zero-crossing timing, and the sum of the currents of the respective phases may be zero.

[0064] Thereby, the charging system 1 (charging device 5) can prevent the dual three-phase motor 3 from rotating when charging the battery 10, and can suppress unnecessary noise and vibration.

[0065] In addition, the control method of the charging system 1 (charging device 5) according to the present embodiment includes a step of the charge / discharge controller 25 (an example of a control unit) outputting a drive signal (OFF signal) for opening the contacts of the relay switch 412 and the relay switch 512 as the external command to the relay switch 412 and the relay switch 512 when charging the battery 10 with the power from the DC power supply bus 204, and a step of outputting a drive signal (ON signal) for closing the contacts of the relay switch 424 and the relay switch 524 as the external command to the relay switch 424 and the relay switch 524.

[0066] Accordingly, the control method of the charging system 1 (charging device 5) can charge the battery 10 of the electric vehicle 100 while ensuring insulation within the dual three-phase motor 3 from a DC power bus 204 such as solar power generation without an insulated power conversion unit by controlling the opening and closing of the contacts of each relay switch. For example, the control method of the charging system 1 (charging device 5) includes relay switches 412, 423, 424, 512, 523, 524, and can charge the battery 10 from the DC power bus 204 by closing the contacts of relay switches 424 and 524 (and opening the contacts of other relay switches).

[0067] Therefore, the control method of the charging system 1 (charging device 5) can charge the battery 10 not only from an AC power supply source but also using the DC power bus 204 (DC power supply source). When charging using the DC power bus 204 (DC power supply source), since an insulated power conversion unit is not required within the charging device 5, the configuration of the charging device 5 and the charging system 1 can be simplified. That is, the control method of the charging system 1 (charging device 5) can simplify the configuration related to charging when charging using the DC power bus 204 (DC power supply source).

[0068] Also, since the control method of the charging system 1 (charging device 5) is configured such that the charge and discharge controller 25 controls the charging operation of the battery 10, the charging control can be completed within the electric vehicle 100, and control by communication with other charging devices (such as a DC power supply source) is not required, thus suppressing the occurrence of problems such as being unable to charge due to communication abnormalities caused by incompatibility between devices.

[0069] Note that the configuration of this embodiment is not limited to the above configuration. For example, in this embodiment, a configuration is adopted that can connect two types of AC power systems, a single-phase AC power system 201 and a three-phase AC power system 202, but a configuration that can connect only one of them may also be used.

[0070] In addition, the DC power supply bus 204 can output DC power and does not require charging control communication with the electric vehicle 100, such as in addition to the power supply by solar power generation shown in this embodiment, a storage battery, a power conversion device with a DC output, etc., and the same effect can be obtained.

[0071] In addition, although a configuration example using an IGBT for the switching devices constituting the first inverter 21, the second inverter 22, and the converter 23 has been shown, other power devices such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) may be used. Also, in the configuration using an IGBT for the switching device, the IGBT is turned off, but when a MOSFET is used for the switching device to be configured, the same effect can be obtained by performing a switching operation so as to achieve a synchronous rectification operation.

[0072] In addition, although the circuit systems of the first inverter 21 and the second inverter 22 are three-phase full-bridge type inverter circuits, they also act in the same manner and the same effect can be obtained even if they are multi-level inverter circuits such as three-level type inverter circuits.

[0073] In addition, the release switch can be configured with a semiconductor switch in addition to a mechanical switch, and the action and effect do not change.

[0074] <Second Embodiment> Next, the second embodiment will be described. The charging system according to this embodiment includes an electric vehicle 100, a single-phase AC power supply system 201, a three-phase AC power supply system 202, and a DC power supply bus 204, similar to the charging system 1 according to the first embodiment.

[0075] [Configuration of Charging System] FIG. 6 is a schematic block diagram showing an example of the configuration of the charging system according to the present embodiment. In FIG. 6, in the configuration of the charging system 1A according to the present embodiment, the parts of the first inverter 21, the second inverter 22, and the dual three-phase motor 3 are extracted and shown. As shown in FIG. 6, the configuration of the charging system 1A (charging device 5A) is different from the configuration of the charging system 1 (charging device 5) shown in FIG. 1 in that relay switches (1311, 1312, 1321, 1322) are provided in the circuit of the first inverter 21 and the second inverter 22 and the dual three-phase motor 3. For the parts other than the configuration shown in this FIG. 6, they are the same as the configuration shown in FIG. 1, and the illustration and description are omitted as appropriate.

[0076] The AC part (AC side) of the first inverter 21 is connected to one side of the first winding 31 of the dual three-phase motor 3, the other side of the first winding 31 is connected to one side of the relay switch 1312, and the other side of the relay switch 1312 is short-circuited between phases. That is, the relay switch 1312 is provided as a relay switch for opening and closing the connection of the neutral point of the first winding 31.

[0077] One side of the contact 1311a of the relay switch 1311 is connected to the inverter side of the U-phase winding of the first winding 31, and the other side is connected to the neutral point side of the W-phase winding of the first winding 31. One side of the contact 1311b of the relay switch 1311 is connected to the inverter side of the W-phase winding of the first winding 31, and the other side is connected to the neutral point side of the V-phase winding of the first winding 31. One side of the contact 1311c of the relay switch 1311 is connected to the inverter side of the V-phase winding of the first winding 31, and the other side is connected to the neutral point side of the U-phase winding of the first winding 31. That is, the relay switch 1311 is provided as a relay switch for opening and closing the Δ connection of the first winding 31.

[0078] The AC part (AC side) of the second inverter 22 is connected to one side of the second winding 32 of the dual three-phase motor 3, the other side of the second winding 32 is connected to one side of the relay switch 1322, and the other side of the relay switch 1322 is short-circuited between phases. That is, the relay switch 1322 is provided as a relay switch for opening and closing the connection of the neutral point of the second winding 32.

[0079] One of the contacts 1321a of the release switch 1321 is connected to the inverter side of the U-phase winding of the second winding 32, and the other is connected to the neutral point side of the W-phase winding of the second winding 32. One of the contacts 1321b of the release switch 1321 is connected to the inverter side of the W-phase winding of the second winding 32, and the other is connected to the neutral point side of the V-phase winding of the second winding 32. One of the contacts 1321c of the release switch 1321 is connected to the inverter side of the V-phase winding of the second winding 32, and the other is connected to the neutral point side of the U-phase winding of the second winding 32. That is, the release switch 1321 is provided as a release switch for opening and closing the Δ-connection of the second winding 32.

[0080] [Operation of the charging system] Next, the operation of the process performed by the charge and discharge controller 25 in the charging system 1A according to the present embodiment will be described with reference to FIGS. 1, 3, 6, and 7.

[0081] FIG. 7 is a flowchart showing an example of the process performed by the charge and discharge controller in the charging system according to the present embodiment.

[0082] (Step S201) The charge and discharge controller 25 determines whether it is in the charging mode. If the charge and discharge controller 25 determines that it is not in the charging mode (NO), it proceeds to step S203.

[0083] (Step S203) After performing the process of step S103 in FIG. 1, the charge and discharge controller 25 performs the process of this step S203. That is, the charge and discharge controller 25 outputs an OFF signal to the release switches 423, 424, the release switches 523, 524, and the release switches 71, 72 to open the contacts, and outputs an ON signal to the release switch 412 and the release switch 512 to close the contacts by the process of step S103 in FIG. 3. As a result, the DC part (DC side) of the second inverter is connected only to the battery 10 and the DC part (DC side) of the first inverter 21.

[0084] Further, as the process of step S203, the charge / discharge controller 25 controls the opening and closing of the contacts of the relay switches 1311, 1321, 1312, and 1322 as follows. The charge / discharge controller 25 outputs an OFF signal to the relay switches 1311 and 1321 to open the contacts of the relay switches 1311 and 1321, and outputs an ON signal to the relay switches 1312 and 1322 to close the contacts of the relay switches 1312 and 1322. Thereby, both the first winding 31 and the second winding 32 of the dual three-phase motor 3 are connected in a Y-connection.

[0085] The charge / discharge controller 25 outputs a gate drive signal to the first inverter 21 and the second inverter 22, thereby causing the first inverter 21 and the second inverter 22 to output a three-phase AC current having a sine wave shape, and rotationally driving the dual three-phase motor 3.

[0086] On the other hand, when it is determined in step S201 that the charging mode is selected (YES), if the connector 121 of the single-phase AC power supply system 201 is connected to the inlet 111, the charge / discharge controller 25 controls so that the AC power from the single-phase AC power supply system 201 is converted into DC power and input to the DC part (DC side) of the second inverter, by the processes shown in steps S105 to S115 of FIG. 3. Further, if the connector 122 of the three-phase AC power supply system 202 is connected to the inlet 112, the charge / discharge controller 25 controls so that the AC power from the three-phase AC power supply system 202 is converted into DC power and input to the DC part (DC side) of the second inverter. Further, if the connector 124 of the DC power supply bus 204 is connected to the inlet 114, the charge / discharge controller 25 controls so that the DC power from the DC power supply bus 204 is input to the DC part (DC side) of the second inverter.

[0087] Also, when it is determined in step S201 that the charging mode is on (YES), the charge / discharge controller 25 proceeds to step S205 and outputs drive signals to the relay switches 1311, 1312, 1321, and 1322 based on the relationship between the DC voltage input to the DC section (DC side) of the second inverter and the DC voltage of the battery 10, and controls the opening and closing of the contacts of each relay switch.

[0088] (Step S205) The charge / discharge controller 25 determines whether the voltage of the DC section (DC side) of the second inverter 22 is higher than √3 times the voltage of the battery 10. When the charge / discharge controller 25 determines that the voltage of the DC section (DC side) of the second inverter 22 is higher than √3 times the voltage of the battery 10 (YES), it proceeds to step S207. On the other hand, when the charge / discharge controller 25 determines that the voltage of the DC section (DC side) of the second inverter 22 is equal to or lower than √3 times the voltage of the battery 10 (NO), it proceeds to step S209.

[0089] (Step S207) The charge / discharge controller 25 outputs an OFF signal to the relay switches 1312 and 1321 to open the contacts of the relay switches 1312 and 1321, and outputs an ON signal to the relay switches 1311 and 1322 to close the contacts of the relay switches 1311 and 1322. As a result, the first winding 31 of the dual three-phase motor 3 is connected in Δ, and the second winding 32 is connected in Y.

[0090] (Step S209) The charge / discharge controller 25 determines whether the voltage of the DC section (DC side) of the second inverter 22 is lower than the voltage of the battery 10. When the charge / discharge controller 25 determines that the voltage of the DC section (DC side) of the second inverter 22 is lower than the voltage of the battery 10 (YES), it proceeds to step S211.

[0091] (Step S211) The charge / discharge controller 25 outputs an OFF signal to the relay switches 1311 and 1322 to open the contacts of the relay switches 1311 and 1322, and outputs an ON signal to the relay switches 1312 and 1321 to close the contacts of the relay switches 1312 and 1321. As a result, the first winding 31 of the dual three-phase motor 3 is connected in a Y-connection, and the second winding 32 is connected in a Δ-connection.

[0092] On the other hand, when the charge / discharge controller 25 determines in step S209 that the voltage of the DC part (DC side) of the second inverter 22 is equal to or higher than the voltage of the battery 10 (NO), it proceeds to step S203. That is, when the charge / discharge controller 25 determines "NO" in both step S205 and step S209, it proceeds to step S203. The case where "NO" is determined in both step S205 and step S209 is, for example, when the voltage of the DC part (DC side) of the second inverter 22 is the same as the voltage of the battery 10.

[0093] As described above, in step S203, the charge / discharge controller 25 outputs an OFF signal to the relay switches 1311 and 1321 to open the contacts of the relay switches 1311 and 1321, and outputs an ON signal to the relay switches 1312 and 1322 to close the contacts of the relay switches 1312 and 1322. As a result, both the first winding 31 and the second winding 32 of the dual three-phase motor 3 are connected in a Y-connection.

[0094] Here, when the connector 121 of the single-phase AC power supply system 201 is connected to the inlet 111, the charge / discharge controller 25 outputs a gate drive signal to the converter 23 to control it so that the power factor of the power flowing from the single-phase AC power supply system 201 to the converter 23 becomes 1. At this time, the AC power from the single-phase AC power supply system 201 is converted into DC power by the operation of the converter 23 and input to the DC part (DC side) of the second inverter.

[0095] Also, when the connector 122 of the three-phase AC power supply system 202 is connected to the inlet 112, the charge and discharge controller 25 outputs a gate drive signal to the converter 23 and controls it so that the power factor of the power flowing from the three-phase AC power supply system 202 to the converter 23 becomes 1. At this time, the AC power from the three-phase AC power supply system 202 is converted into DC power by the operation of the converter 23 and input to the DC part (DC side) of the second inverter.

[0096] Also, when the connector 124 of the DC power supply bus 204 is connected to the inlet 114, the DC power from the DC power supply bus 204 is input to the DC part (DC side) of the second inverter.

[0097] The charge and discharge controller 25 outputs a gate drive signal to the second inverter 22 and controls it so that the output current of the second inverter 22 has a current waveform in which no rotational torque is generated in the dual three-phase motor 3. For example, as shown in FIG. 4, the currents of the U-phase, V-phase, and W-phase are controlled so that the internal magnetic field of the dual three-phase motor 3 becomes an alternating magnetic field and the current waveform in which no rotational torque is generated. Also, the charge and discharge controller 25 outputs a gate drive signal to the first inverter 21 so as to turn off all the IGBTs and operates the first inverter 21 as a rectifier circuit.

[0098] At this time, when the high-frequency AC current output by the second inverter 22 flows through the second winding 32 of the dual three-phase motor 3, the dual three-phase motor 3 operates as a current transformer (CT), and a current flows through the first winding 31 so as to cancel the internal magnetic flux in the iron core of the dual three-phase motor 3. This current is rectified by the first inverter 21 to charge the battery 10. Also, the charge and discharge controller 25 acquires the state information of the battery 10 from the battery controller 15 and controls the above charging operation based on the acquired state information of the battery 10.

[0099] In this way, in addition to the processes described in the first embodiment (see FIG. 3), the charge and discharge controller 25 opens and closes the contacts of the relay switches 1311, 1312, 1321, and 1322, and changes the connection of the windings of the first winding 31 and the second winding 32 of the dual three-phase motor 3 between Y-connection and Δ-connection.

[0100] Thereby, even when the voltage of the DC power supply bus 204 is low and the voltage on the DC side of the second inverter 22 is lower than the voltage of the battery 10, the charge and discharge controller 25 connects the second winding 32 of the dual three-phase motor 3 in Δ-connection and connects the first winding 31 of the dual three-phase motor 3 in Y-connection, so that the voltage on the DC side of the second inverter is boosted and output to the DC side of the first inverter 21, enabling the battery 10 to be charged.

[0101] Also, when the voltage of the DC power supply bus 204 is high and the voltage on the DC side of the second inverter is higher than √3 times the voltage of the battery 10, the charge and discharge controller 25 connects the second winding 32 of the dual three-phase motor 3 in Y-connection and connects the first winding 31 of the dual three-phase motor 3 in Δ-connection, so that the voltage on the DC side of the second inverter 22 is stepped down to 1 / √3 times and output to the DC side of the first inverter 21. At this time, since the current becomes √3 times, the current for charging the battery 10 increases, and the charging time can be shortened.

[0102] As described above, the charging system 1A (charging device 5A) according to the present embodiment includes a relay switch 1311 (an example of a third relay switch) that opens and closes the Δ-connection of the first winding 31 (an example of one winding of the multi-winding), a relay switch 1312 (an example of a fourth relay switch) that opens and closes the connection of the neutral point of the first winding 31, a relay switch 1321 (an example of a fifth relay switch) that opens and closes the Δ-connection of the second winding 32 (an example of the other winding of the multi-winding), and a relay switch 1322 (an example of a sixth relay switch) that opens and closes the connection of the neutral point of the second winding 32.

[0103] When the charge / discharge controller 25 does not charge the battery 10 from the DC power bus 204, it turns on the relay switches 1312 and 1322 and turns off the relay switches 1311 and 1321 (see step S203 in FIG. 7). In this case, both the first winding 31 and the second winding 32 of the dual three-phase motor 3 are connected in a Y-connection.

[0104] Also, when the charge / discharge controller 25 charges the battery 10 from the DC power bus 204, for example, it performs the following first control, second control, or third control. In the first control, the charge / discharge controller 25 turns on the relay switches 1312 and 1322 and turns off the relay switches 1311 and 1321 (see step S203 in FIG. 7). In this case, both the first winding 31 and the second winding 32 of the dual three-phase motor 3 are connected in a Y-connection (no step-up / step-down).

[0105] In the second control, the charge / discharge controller 25 turns on the relay switches 1312 and 1321 and turns off the relay switches 1311 and 1322 (see step S211 in FIG. 7). In this case, the first winding 31 of the dual three-phase motor 3 is connected in a Y-connection, and the second winding 32 is connected in a Δ-connection (step-up).

[0106] In the third control, the charge / discharge controller 25 turns on the relay switches 1311 and 1322 and turns off the relay switches 1312 and 1321 (see step S207 in FIG. 7). In this case, the first winding 31 of the dual three-phase motor 3 is connected in a Δ-connection, and the second winding 32 is connected in a Y-connection (step-down).

[0107] As a result, when charging the battery 10, the charging system 1A (charging device 5A) can change the connection of the first winding 31 and the second winding 32 of the dual three-phase motor 3 to a Y connection or a Δ connection. Therefore, even if the voltage of the battery 10 does not match the voltage of the DC power supply bus 204 (DC power supply source), the battery 10 can be charged using the DC power supply bus 204.

[0108] Also, when charging the battery 10, if the voltage of the battery 10 is lower than 1 / √3 of the voltage of the DC power supply bus 204 (DC power supply source), the charging system 1A (charging device 5A) can increase the charging current to the battery 10 and shorten the charging time of the battery 10.

[0109] Note that the configuration of this embodiment is not limited to the above configuration. For example, as the process of step S203, the charge and discharge controller 25 outputs an OFF signal to the relay switches 1312 and 1322 to open the contacts of the relay switches 1312 and 1322, and outputs an ON signal to the relay switches 1311 and 1321 to close the contacts of the relay switches 1311 and 1321, so that both the first winding 31 and the second winding 32 of the dual three-phase motor 3 may be connected in a Δ connection.

[0110] Also, the positions where the contacts 1311a, 1311b, and 1311c of the relay switch 1311 are connected only need to be able to connect the first winding 31 in a Δ connection by closing all the contacts of the relay switch 1311, and are not limited to the connection positions shown in FIG. 6. FIG. 8 is a diagram showing another example of the connection of the relay switch 1311 (an example of the third relay switch) according to this embodiment. For example, as shown in FIG. 8, the contacts 1311a, 1311b, and 1311c of the relay switch 1311 may be connected to the first winding 31.

[0111] Similarly, the positions for connecting the contacts 1321a, 1321b, and 1321c of the release switch 1321 only need to be able to connect the connection of the second winding 32 to a Δ connection by closing all the contacts of the release switch 1321, and are not limited to the connection positions shown in FIG. 6. For example, similar to the connection of each contact of the release switch 1311 shown in FIG. 8 to the first winding 31, each contact of the release switch 1321 may be connected to the second winding 32.

[0112] Also, the positions for connecting the contacts 1312a, 1312b, and 1312c of the release switch 1312 only need to be able to configure the neutral point of the first winding 31 by closing all the contacts of the release switch 1312, and are not limited to the connection positions shown in FIG. 6. FIG. 9 is a diagram showing another example of the connection of the release switch 1312 (an example of the fourth release switch) according to the present embodiment. For example, as shown in FIG. 9, the contacts 1312a, 1312b, and 1312c of the release switch 1312 may be connected to the first winding 31.

[0113] Similarly, the positions for connecting the contacts 1322a, 1322b, and 1322c of the release switch 1322 only need to be able to configure the neutral point of the second winding 32 by closing all of the release switch 1322, and are not limited to the connection positions shown in FIG. 6. For example, similar to the connection of each contact of the release switch 1312 shown in FIG. 9 to the first winding 31, each contact of the release switch 1322 may be connected to the second winding 32.

[0114] Note that a program for realizing the function of the charge and discharge controller 25 (an example of a control unit) may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to perform the processing of the charge and discharge controller 25. Here, the “computer system” is assumed to include hardware such as an OS and peripheral devices.

[0115] In addition, the "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, etc., and storage devices such as hard disks built into computer systems. Furthermore, the "computer-readable recording medium" includes those that dynamically hold a program for a short period of time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, and those that hold a program for a certain period of time, like the volatile memory inside a computer system that serves as a server or client in that case. Also, the above program may be for realizing a part of the aforementioned functions, and may further be realizable in combination with a program already recorded in a computer system for realizing the aforementioned functions. Also, the above program may be stored in a predetermined server and distributed (downloaded, etc.) via a communication line in response to a request from another device.

[0116] Also, part or all of the functions of the charge / discharge controller 25 may be realized as an integrated circuit such as an LSI (Large Scale Integration). Each function may be made into an individual processor, or part or all of them may be integrated and made into a processor. Also, the method of integrating into a circuit is not limited to LSI and may be realized by a dedicated circuit or a general-purpose processor. Also, when a technology for integrating into a circuit that replaces LSI appears due to the progress of semiconductor technology, an integrated circuit using such technology may be used.

[0117] As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and the embodiments of the present disclosure can be appropriately modified or omitted.

Explanation of Reference Numerals

[0118] 1 Charging system 5, 5A Charging device 10 Battery 15 Battery controller 21 First inverter 21aH U-phase upper-arm IGBT and FWD of the first inverter 21aL U-phase lower-arm IGBT and FWD of the first inverter 21bH V-phase upper-arm IGBT and FWD of the first inverter 21bL V-phase lower-arm IGBT and FWD of the first inverter 21cH W-phase upper-arm IGBT and FWD of the first inverter 21cL W-phase lower-arm IGBT and FWD of the first inverter 22 Second inverter 22aH U-phase upper-arm IGBT and FWD of the second inverter 22aL U-phase lower-arm IGBT and FWD of the second inverter 22bH V-phase upper-arm IGBT and FWD of the second inverter 22bL V-phase lower-arm IGBT and FWD of the second inverter 22cH W-phase upper-arm IGBT and FWD of the second inverter 22cL W-phase lower-arm IGBT and FWD of the second inverter 23 Converter 25 Charge and discharge controller 3 Dual three-phase motor 31a U-phase winding of the first winding of the dual three-phase motor 31b V-phase winding of the first winding of the dual three-phase motor 31c W-phase winding of the first winding of the dual three-phase motor 32 Second winding of the dual three-phase motor 32a U-phase winding of the second winding of the dual three-phase motor 32b V-phase winding of the second winding of the dual three-phase motor 32c W-phase winding of the second winding of the dual three-phase motor 412, 423, 424 Relay switches 512, 523, 524 Relay switches 6 Filter 71, 72 Relay switches 111, 112, 114 Inlets 121, 122, 124 Connectors 1311, 1312, 1321, 1322 relay switches 1311a~c, 1312a~c, 1321a~c, 1322a~c contacts 201 single-phase AC power supply system 202 three-phase AC power supply system 204 DC power bus

Claims

1. A charging device that charges a battery with power from a DC power supply, comprising: a motor having a multi-winding; a first inverter connected between one winding of the multi-winding and the battery, converting the input DC power into AC power and outputting it to the motor; a second inverter connected between the other winding of the multi-winding and the battery, converting the input DC power into AC power and outputting it to the motor; a first relay switch connected between the battery and the second inverter, opening and closing the contacts between the contacts by an external command; a second relay switch connected between the DC power supply and the second inverter, opening and closing the contacts between the contacts by an external command; a battery monitoring unit that monitors the state of the battery; a control unit that acquires information indicating the state of the battery from the battery monitoring unit and outputs drive signals to the first inverter, the second inverter, the first relay switch, and the second relay switch based on the acquired information indicating the state of the battery; and comprising: wherein the control unit: when charging the battery with power from the DC power supply, outputs a drive signal for opening the contacts of the first relay switch as the external command to the first relay switch, and outputs a drive signal for closing the contacts of the second relay switch as the external command to the second relay switch; a charging device.

2. wherein the control unit: when not charging the battery with power from the DC power supply, outputs a drive signal for closing the contacts of the first relay switch as the external command to the first relay switch, and outputs a drive signal for opening the contacts of the second relay switch as the external command to the second relay switch; The charging device according to claim 1.

3. a third relay switch for opening and closing the Δ connection of one winding of the multi-winding; a fourth relay switch for opening and closing the connection of the neutral point of one winding of the multi-winding; a fifth relay switch for opening and closing the Δ connection of the other winding of the multi-winding; a sixth relay switch for opening and closing the connection of the neutral point of the other winding of the multi-winding; and comprising: wherein the control unit: when not charging the battery from the DC power supply: turns on the fourth relay switch and the sixth relay switch, and turns off the third relay switch and the fifth relay switch. Or turn on the third release switch and the fifth release switch, and turn off the fourth release switch and the sixth release switch. When charging the battery from the DC power supply, turn on the fourth release switch and the sixth release switch, and turn off the third release switch and the fifth release switch. Or turn on the fourth release switch and the fifth release switch, and turn off the third release switch and the sixth release switch. Or turn on the third release switch and the sixth release switch, and turn off the fourth release switch and the fifth release switch. The charging device according to claim 1.

4. When charging the battery from the DC power supply, the waveform of the output current of the second inverter is a current waveform in which no rotational torque is generated in the motor. The charging device according to claim 1 or claim 3.

5. When charging the battery from the DC power supply, the waveform of the output current of each phase of the second inverter is an alternating current or a zero current in which the zero-crossing timing coincides, and the sum of the currents of each phase is zero. The charging device according to claim 4.

6. The charging device according to claim 1, the battery connected to the DC side of the first inverter, the DC power supply connected to the second release switch via a connection portion, comprising: the DC power supply does not include an insulated power conversion unit. Charging system.

7. A charging system comprising a battery, a DC power supply, and a charging device for charging the battery with power from the DC power supply, a motor having multiple windings, a first inverter connected between one of the multiple windings and the battery, converting the input DC power into AC power and outputting it to the motor, a second inverter connected between the other winding of the multiple windings and the battery, converting the input DC power into AC power and outputting it to the motor, a first release switch connected between the battery and the second inverter, opening and closing the contacts by an external command, a second release switch connected between the DC power supply and the second inverter, opening and closing the contacts by an external command, a battery monitoring unit for monitoring the state of the battery. The control unit acquires information indicating the state of the battery from the battery monitoring unit, and outputs drive signals to the first inverter, the second inverter, the first relay switch, and the second relay switch based on the acquired information indicating the state of the battery. It is provided with The control unit When charging the battery from the DC power supply, the control unit outputs a drive signal for opening the contacts of the first relay switch as the external command to the first relay switch, and outputs a drive signal for closing the contacts of the second relay switch as the external command to the second relay switch. Charging system.

8. A motor having a multi-winding, a first inverter connected between one winding of the multi-winding and a battery, converting the input DC power into AC power and outputting it to the motor, and the other winding of the multi-winding and the battery A second inverter connected between and converting the input DC power into AC power and outputting it to the motor, a first relay switch connected between the battery and the second inverter and opening and closing between contacts by an external command, and a DC power supply and the second inverter A second relay switch connected between and opening and closing between contacts by an external command, a battery monitoring unit for monitoring the state of the battery, and information indicating the state of the battery is acquired from the battery monitoring unit, and based on the acquired information indicating the state of the battery, the first inverter, the second inverter, the first relay switch, and the second relay switch are provided. A control method for a charging device that includes a control unit that outputs a drive signal to the control unit, and when the control unit charges the battery from the DC power supply, When the control unit charges the battery from the DC power supply, Outputting, as the external command, a drive signal for opening the contacts of the first relay switch to the first relay switch; Outputting, as the external command, a drive signal for closing the contacts of the second relay switch to the second relay switch; A control method including

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