Electric power conversion system and program

Abstract

To provide an electric power conversion system and a program capable of simplifying a configuration.SOLUTION: An electric power conversion system includes a high-potential-side electrical path 22H, a low-potential-side electrical path 22L, an inverter 20, a motor 10 having an armature winding 11, a first current sensor 73 that detects a current flowing through a first storage battery 31, a second current sensor 74 that detects a current flowing through a second storage battery 32, an inter-battery electrical path 24, a motor-side electrical path 25, and a motor-side switch 60. When the motor-side switch 60 is turned off, the first storage battery 31 and the second storage battery 32 are electrically disconnected from the armature winding 11. When the motor-side switch 60 is turned on, the second storage battery 32 and the armature winding 11 are electrically connected to each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power conversion device and a program. [Background technology]

[0002] As described in Patent Document 1, a conventional in-vehicle system is known that includes a motor, an inverter electrically connected to an armature winding of the motor, and first and second power storage units. This system includes a relay for switching the connection state of the first and second power storage units between a series connection state and a parallel connection state. This allows the first and second power storage units to be charged using either an external charger with a charging voltage of 400 V or an external charger with a charging voltage of 800 V. Furthermore, when an external charger with a charging voltage of 400 V is used, the first and second power storage units are connected in parallel, allowing the first and second power storage units to be charged by lowering the system voltage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6930306 Summary of the Invention

[0004] It is desirable to simplify as much as possible the configuration for switching the connection states between the first and second power storage units and the armature winding.

[0005] A main object of the present disclosure is to provide a power conversion device and a program that can simplify the configuration.

[0006] The present disclosure provides a power supply including: a high-potential side electrical path (22H) electrically connectable to a positive electrode terminal of a first power storage unit (31); a low potential side electrical path (22L) electrically connectable to a negative electrode terminal of the second power storage unit (32); an inverter (20) having an upper arm switch (SWH) electrically connected to the high potential side electrical path and a lower arm switch (SWL) electrically connected to the low potential side electrical path; a motor (10) having an armature winding (11) electrically connected to a connection point between the upper arm switch and the lower arm switch via a conductive member (23); a first current sensor (73) that detects a current flowing in the first power storage unit; a second current sensor (74) that detects a current flowing through the second power storage unit; In a power conversion device comprising: an inter-power storage unit electrical path (24) that electrically connects the negative electrode terminal of the first power storage unit and the positive electrode terminal of the second power storage unit; a motor-side electrical path (25-28) electrically connecting the armature winding and the electrical path between the power storage unit; a motor-side switch (60) provided in the motor-side electrical path; Equipped with. In the present disclosure, when the motor-side switch is turned off, the first power storage unit and the second power storage unit are electrically disconnected from the armature winding, When the motor-side switch is turned on, the second power storage unit and the armature winding are electrically connected to each other.

[0007] This makes it possible to provide a power conversion device with a simplified configuration for switching the connection states between the first and second power storage units and the armature winding. [Brief explanation of the drawings]

[0008] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: [Figure 1] FIG. 1 is a diagram showing the overall configuration of a system according to a first embodiment; [Figure 2] FIG. 2 is a flowchart showing the procedure of the charging process. [Figure 3]FIG. 3 is a diagram showing switch operation during high-voltage charging; [Figure 4] FIG. 4 is a diagram showing switch operation during low-voltage charging; [Figure 5] FIG. 5 is a diagram showing the overall configuration of a system according to a second embodiment; [Figure 6] FIG. 6 is a flowchart showing the procedure of the charging process. [Figure 7] FIG. 7 is a diagram showing the overall configuration of a system according to the third embodiment; [Figure 8] FIG. 8 is a flowchart showing the procedure of the charging process. [Figure 9] FIG. 9 is a diagram showing switch operation modes during low-voltage charging; [Figure 10] FIG. 10 is a diagram showing switch operation modes during low-voltage charging; [Figure 11] FIG. 11 is a diagram showing the overall configuration of a system according to a fourth embodiment; [Figure 12] FIG. 12 is a flowchart showing the procedure of the charging process. [Figure 13] FIG. 13 is a diagram showing the overall configuration of a system according to a fifth embodiment; [Figure 14] FIG. 14 is a flowchart showing the procedure of the charging process. [Figure 15] FIG. 15 is a diagram showing the overall configuration of a system according to a sixth embodiment; [Figure 16] FIG. 16 is a diagram showing the overall configuration of a system according to a modification of the sixth embodiment; [Figure 17] FIG. 17 is a diagram showing the overall configuration of a system according to a modification of the sixth embodiment; [Figure 18] FIG. 18 is a diagram showing the overall configuration of a system according to a modification of the sixth embodiment; [Figure 19] FIG. 19 is a diagram showing the overall configuration of a system according to the seventh embodiment; [Figure 20] FIG. 20 is a diagram showing switch operation modes when precharging with the first storage battery; [Figure 21]FIG. 21 is a diagram showing switch operation modes when precharging with a second storage battery; [Figure 22] FIG. 22 is a diagram showing the overall configuration of a system according to the eighth embodiment; [Figure 23] FIG. 23 is a diagram showing switch operation modes when precharging with the first storage battery; [Figure 24] FIG. 24 is a diagram showing the overall configuration of a system according to a modification of the seventh embodiment; [Figure 25] FIG. 25 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 26] FIG. 26 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 27] FIG. 27 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 28] FIG. 28 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 29] FIG. 29 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 30] FIG. 30 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 31] FIG. 31 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 32] FIG. 32 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 33] FIG. 33 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 34] FIG. 34 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 35] FIG. 35 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 36] FIG. 36 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 37] FIG. 37 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 38] FIG. 38 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 39] FIG. 39 is a diagram showing the operation of the switches during low-voltage charging in the configuration of FIG. 38; [Figure 40] FIG. 40 is a diagram showing the overall configuration of a system according to another embodiment; [Figure 41] FIG. 41 is a diagram showing the overall configuration of a system according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be assigned the same reference numerals or reference numerals that differ in the hundredth or more digit. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments.

[0010] First Embodiment A first embodiment of a power conversion device according to the present disclosure will now be described with reference to the drawings. The power conversion device of this embodiment is mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and forms an in-vehicle system.

[0011] The system includes a power conversion device. As shown in FIG. 1, the power conversion device includes a motor 10, an inverter 20, a high-potential side electrical path 22H, and a low-potential side electrical path 22L. The motor 10 is a three-phase synchronous machine and includes star-connected armature windings 11 of U, V, and W phases, and a rotor (not shown). The armature windings 11 of each phase are arranged with an electrical angle offset of 120°. The motor 10 is, for example, a permanent magnet synchronous machine. The rotor is capable of transmitting power to the drive wheels of the vehicle. Therefore, the motor 10 serves as a source of torque for propelling the vehicle.

[0012] The inverter 20 includes three phases of series-connected upper-arm switches SWH and lower-arm switches SWL. An upper-arm diode DH, which is a freewheeling diode, is connected in antiparallel to the upper-arm switch SWH, and a lower-arm diode DL, which is also a freewheeling diode, is connected in antiparallel to the lower-arm switch SWL. In this embodiment, each of the switches SWH and SWL is an IGBT.

[0013] The inverter 20 includes a smoothing capacitor 21. A high-potential terminal of the smoothing capacitor 21 is connected to a first end of a long high-potential electrical path 22H. A low-potential terminal of the smoothing capacitor 21 is connected to a first end of a long low-potential electrical path 22L. The smoothing capacitor 21 may be provided outside the inverter 20.

[0014] In each phase, a first end of the armature winding 11 is connected to a connection point between an emitter, which is a low-potential terminal of the upper arm switch SWH, and a collector, which is a high-potential terminal of the lower arm switch SWL, via a conductive member 23 such as a bus bar. Second ends of the armature windings 11 of each phase are connected to each other at a neutral point. In this embodiment, the armature windings 11 of each phase are set to have the same number of turns. As a result, the armature windings 11 of each phase are set to have the same inductance, for example.

[0015] A high-potential side electrical path 22H is connected to the collector of the upper arm switch SWH of each phase, and a low-potential side electrical path 22L is connected to the emitter of the lower arm switch SWL of each phase.

[0016] The system includes a first storage battery 31 (corresponding to the "first power storage unit") and a second storage battery 32 (corresponding to the "second power storage unit"). Each of the storage batteries 31, 32 serves as a power supply source for driving the rotor of the motor 10 to rotate. Each of the storage batteries 31, 32 is an assembled battery configured as a series connection of battery cells, which are single cells. The positive terminal of the first storage battery 31 is connected to the high-potential side electrical path 22H, and the negative terminal of the second storage battery 32 is connected to the low-potential side electrical path 22L. The terminal voltages (e.g., rated voltages) of the battery cells constituting the assembled battery are set to be the same, for example. The battery cells are, for example, secondary batteries such as lithium-ion batteries.

[0017] Each of the storage batteries 31, 32 can be charged by an external charger (described later) that is provided outside the vehicle. The external charger is, for example, a stationary charger. A positive electrode side connection part to which a positive terminal of the external charger can be connected is provided at a second end of the high-potential side electrical path 22H opposite to the connection point of the smoothing capacitor 21. A negative electrode side connection part to which a negative terminal of the external charger can be connected is provided at a second end of the low-potential side electrical path 22L opposite to the connection point of the smoothing capacitor 21.

[0018] The power conversion device includes a main switch for electrically connecting or disconnecting the first and second storage batteries 31, 32 and the inverter 20. Specifically, the main switches include a high-side main switch SMRH and a low-side main switch SMRL. The power conversion device also includes a charging switch for electrically connecting or disconnecting the first and second storage batteries 31, 32 and an external charger. Specifically, the charging switches include a high-side charging switch DCRH and a low-side charging switch DCRL. In this embodiment, the switches SMRH, SMRL, DCRH, and DCRL are mechanical relays. When turned off, the switches SMRH, SMRL, DCRH, and DCRL block bidirectional current flow, and when turned on, allow bidirectional current flow. The high-side electrical path 22H is provided, in order from the inverter 20 side, with the high-side main switch SMRH and the high-side charging switch DCRH. The low-side electrical path 22L is provided, in order from the inverter 20 side, with the low-side main switch SMRL and the low-side charging switch DCRL. The high potential side main switch SMRH, the low potential side main switch SMRL, the high potential side charging switch DCRH and the low potential side charging switch DCRL are not limited to mechanical relays and may be semiconductor switching elements, for example.

[0019] The power conversion device includes an inter-battery switch 40, a bypass switch 50, and a motor-side switch 60 as switches for switching the connection state of the first storage battery 31 and the second storage battery 32 between a state in which they are connected in series to an external charger or a state in which they are connected via a motor. In this embodiment, the inter-battery switch 40, the bypass switch 50, and the motor-side switch 60 are mechanical relays. When turned off, the inter-battery switch 40, the bypass switch 50, and the motor-side switch 60 block the flow of bidirectional current, and when turned on, allow the flow of bidirectional current. Note that the inter-battery switch 40, the bypass switch 50, and the motor-side switch 60 are not limited to mechanical relays and may be, for example, semiconductor switching elements.

[0020] The inter-battery switch 40 is provided in the inter-battery electrical path 24 (corresponding to the "inter-power storage unit electrical path") that connects the negative terminal of the first storage battery 31 and the positive terminal of the second storage battery 32. When the inter-battery switch 40 is turned on, the negative terminal of the first storage battery 31 and the positive terminal of the second storage battery 32 are electrically connected. On the other hand, when the inter-battery switch 40 is turned off, the negative terminal of the first storage battery 31 and the positive terminal of the second storage battery 32 are electrically disconnected.

[0021] The bypass switch 50 connects the negative terminal of the first storage battery 31 and the low potential side electrical path 22L. When the bypass switch 50 is turned on, the negative terminal of the first storage battery 31 and the negative terminal of the second storage battery 32 are electrically connected. On the other hand, when the bypass switch 50 is turned off, the negative terminal of the first storage battery 31 and the negative terminal of the second storage battery 32 are electrically disconnected.

[0022] The motor-side switch 60 is provided on a motor-side electrical path 25 that connects the second storage battery 32 side of the inter-battery switch 40 of the inter-battery electrical path 24 with the neutral point of the armature winding 11. When the motor-side switch 60 is turned on, the neutral point of the armature winding 11 is electrically connected to the positive terminal of the second storage battery 32. When the motor-side switch 60 is turned off, the neutral point of the armature winding 11 is electrically disconnected from the positive terminal of the second storage battery 32.

[0023] The power conversion device includes a first voltage sensor 71 that detects the terminal voltage of the first storage battery 31 and a second voltage sensor 72 that detects the terminal voltage of the second storage battery 32. The power conversion device includes a first current sensor 73 that detects the current flowing through the first storage battery 31 and a second current sensor 74 that detects the current flowing through the second storage battery 32. The first current sensor 73 is provided on an electrical path connecting the positive terminal of the first storage battery 31 and the high-potential side electrical path 22H. The second current sensor 74 is provided on an electrical path connecting the negative terminal of the second storage battery 32 and the low-potential side electrical path 22L. The power conversion device also includes, as other sensors, a rotation angle sensor that detects the rotation angle (electrical angle) of the rotor and phase current sensors that detect phase currents flowing through the armature windings 11 of each phase.

[0024] The detected values ​​of each sensor are input to a control device 100 (corresponding to a "controller") included in the power conversion device. The control device 100 is mainly configured with a microcomputer 101, which includes a CPU. The functions provided by the microcomputer 101 can be provided by software recorded in a physical memory device and a computer that executes the software, by software alone, by hardware alone, or a combination thereof. For example, when the microcomputer 101 is provided by a hardware electronic circuit, the function can be provided by a digital circuit including multiple logic circuits or an analog circuit. For example, the microcomputer 101 executes a program stored in a non-transitory tangible storage medium that serves as a memory unit included in the microcomputer 101. The program includes, for example, a program for the processing shown in FIG. 2 (described later). Execution of the program results in the execution of a method corresponding to the program. The memory unit is, for example, a non-volatile memory. The program stored in the memory unit can be updated via a communication network such as the Internet, for example, via OTA (Over The Air) or the like.

[0025] The control device 100 performs switching control of the switches SWH and SWL constituting the inverter 20 to feedback control the control amount of the motor 10 to a command value based on the detection values ​​of each sensor. The control amount is, for example, torque. In each phase, the upper arm switch SWH and the lower arm switch SWL are alternately turned on. This feedback control transmits the rotational power of the rotor to the drive wheels, causing the vehicle to run.

[0026] The positive electrode connection portion of the high-potential side electrical path 22H and the negative electrode connection portion of the low-potential side electrical path 22L are interfaces for connection to an external charger. In this embodiment, the external charger is a high-voltage charger 200 or a low-voltage charger 210 (see FIG. 3 ). The charging voltage of the high-voltage charger 200 is approximately the same as the inter-terminal voltage (specifically, the rated voltage) of the series-connected assembly of the first and second storage batteries 31 and 32, for example, 800 V. The charging voltage of the low-voltage charger 210 is lower than the rated voltage of the series-connected assembly of the first and second storage batteries 31 and 32, for example, 400 V. For example, when a user or an operator connects an external charger to each connection portion and charges the first and second storage batteries 31 and 32 using the external charger, the high-potential side charging switch DCRH and the low-potential side charging switch DCRL are switched on by the control device 100.

[0027] On the other hand, when charging by an external charger is not being performed or when an external charger is not connected, the high-side charging switch DCRH and the low-side charging switch DCRL are switched off by the control device 100. If the positive-side connection portion and the negative-side connection portion are exposed to the outside from the housing of the power conversion device, they may be touched by a user or worker. By switching off the high-side charging switch DCRH and the low-side charging switch DCRL, electric shock is prevented.

[0028] Next, the charging process by the external charger will be described with reference to Fig. 2. This process is executed by the control device 100.

[0029] In step S10, it is determined whether the external charger connected to each connection part of each electrical path 22H, 22L is the high-voltage charger 200. This process is for determining whether the connection state of the first and second storage batteries 31, 32 should be set to a series connection state.

[0030] If it is determined in step S10 that the external charger is the high-voltage charger 200, the process proceeds to step S11, where the inter-battery switch 40, the bypass switch 50, the motor-side switch 60, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage charger 200.

[0031] Specifically, the inter-battery switch 40 is turned on, and the bypass switch 50, the motor-side switch 60, and the upper and lower arm switches SWH, SWL of all phases of the inverter 20 are turned off. As a result, the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage charger 200, as shown in FIG. 3. Therefore, current flows through a closed circuit including the high-voltage charger 200, the high-potential side electrical path 22H, the first storage battery 31, the inter-battery switch 40, the second storage battery 32, and the low-potential side electrical path 22L, and the first storage battery 31 and the second storage battery 32 are charged in a series-connected state. At this time, because the upper arm switch SWH and the motor-side switch 60 of the inverter 20 are turned off, the charging current of the high-voltage charger 200 is prevented from flowing to the inverter 20 and the armature winding 11. Note that the main switches SMRH, SMRL and the charging switches DCRH, DCRL are not shown in FIG. 3.

[0032] Returning to the explanation of Fig. 2, if it is determined in step S10 that the external charger is not the high-voltage charger 200, the process proceeds to step S12, where it is determined whether the connected external charger is the low-voltage charger 210. This process is for determining whether the connection state of the first and second storage batteries 31, 32 should be changed to a motor-via-connection state.

[0033] If it is determined in step S12 that the external charger is the low-voltage charger 210, the process proceeds to step S13, where the inter-battery switch 40, the bypass switch 50, the motor-side switch 60, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the connection state of the first and second storage batteries 31, 32 becomes a motor-via-connection state. This reduces the system voltage to a voltage equivalent to the charging voltage of the low-voltage charger 210, making it possible to take measures against ground faults during charging by the low-voltage charger 210.

[0034] Specifically, the inter-battery switch 40 is turned off, and the bypass switch 50 and the motor-side switch 60 are turned on. Furthermore, the lower-arm switches SWL of all phases of the inverter 20 are turned off, and the upper-arm switch SWH of at least one phase is turned on. As a result, as shown in FIG. 4 , the first storage battery 31 and the second storage battery 32 are connected to the low-voltage charger 210 via the motor. Therefore, current flows through a closed circuit including the low-voltage charger 210, the high-potential side electrical path 22H, the first storage battery 31, the bypass switch 50, and the low-potential side electrical path 22L, thereby charging the first storage battery 31. Furthermore, current flows through a closed circuit including the low-voltage charger 210, the high-potential side electrical path 22H, the upper-arm switch SWH, the armature winding 11, the neutral point, the motor-side switch 60, the second storage battery 32, and the low-potential side electrical path 22L, thereby charging the second storage battery 32. When the upper-arm switches SWH of multiple phases are turned on in step S13, the impedance of the charging path can be reduced.

[0035] The processing of step S13 enables the connection state of the first and second storage batteries 31, 32 to be changed to a motor-mediated connection state, thereby enabling the first storage battery 31 to be directly charged by the low-voltage charger 210, and the second storage battery 32 to be charged via the inverter 20 and the armature winding 11. Furthermore, even if the first and second storage batteries 31, 32 have different rated voltages, or even if the first and second storage batteries 31, 32 have the same rated voltage but different actual terminal voltages, the first and second storage batteries 31, 32 can be charged simultaneously without an additional power conversion circuit.

[0036] According to the present embodiment described above in detail, the configuration for lowering the system voltage in accordance with the charging voltage of the low-voltage charger 210 can be realized by utilizing part of the configuration of the inverter 20 and the motor 10. Therefore, it is possible to provide a power conversion device with a simplified configuration for switching the connection states of the first and second storage batteries 31, 32.

[0037] <Modification of the first embodiment> 2, the upper arm switch SWH of at least one phase and the motor-side switch 60 may be turned on, provided that the upper and lower arm switches SWH, SWL of the same phase of the inverter 20 are not turned on. Also, in step S11, switching may be performed by repeatedly turning on and off either one of the upper and lower arm switches SWH, SWL of the same phase, or by alternately turning on the upper and lower arm switches SWH, SWL of the same phase.

[0038] In step S13, the upper arm switch SWH is not limited to being kept on, but may be switched on and off repeatedly, or may be switched on alternately in at least one phase. In this case, for example, based on the detected value of the electrical angle, switching may be performed so that the torque of the motor 10 is 0 or a value close to 0 (specifically, for example, the q-axis current flowing through the armature winding 11 is 0 or a value close to 0).

[0039] After the affirmative determination in step S12, the process of step S13 may be performed if it is determined that the terminal voltage of the first storage battery 31 detected by the first voltage sensor 71 (hereinafter referred to as the first detected voltage VA) is equal to or higher than the terminal voltage of the second storage battery 32 detected by the second voltage sensor 72 (hereinafter referred to as the second detected voltage VB). Alternatively, after the affirmative determination in step S12, the process of step S13 may be performed if it is determined that the second detected voltage VB is higher than the first detected voltage VA and that the value obtained by subtracting the first detected voltage VA from the second detected voltage VB is equal to or lower than a threshold value ΔVjde (>0, corresponding to a second threshold value ΔVjde2 described later). This can prevent a current from flowing from the second storage battery 32 to the first storage battery 31 via the motor-side electrical path 25, the armature winding 11, the upper-arm diode DH, and the high-potential-side electrical path 22H when the operational states of the switches are switched as in step S13, or can reduce the amount of current that flows in even if this phenomenon occurs.

[0040] The threshold value ΔVjde is a value smaller than the rated voltage of each of the storage batteries 31, 32. The threshold value ΔVjde is set, for example, to a value equal to or less than 1 / 10, 1 / 20, 1 / 50, or 1 / 100 of the lower of the rated voltages of the storage batteries 31, 32. A situation in which the second detection voltage VB and the first detection voltage VA differ greatly may occur, for example, in the following cases (1) to (3).

[0041] (1) When the rated voltages of the battery cells constituting the storage batteries 31, 32 are the same, the number of battery cells constituting the first storage battery 31 is different from the number of battery cells constituting the second storage battery 32.

[0042] (2) In a configuration in which the number of battery cells constituting each of the storage batteries 31 and 32 is the same, the types of the storage batteries 31 and 32 are different and the rated voltages of the battery cells of the storage batteries 31 and 32 are different.

[0043] (3) The storage batteries 31, 32 have different numbers of battery cells, and the types of the storage batteries 31, 32 are different, so that the rated voltages of the battery cells of the storage batteries 31, 32 are different.

[0044] Second Embodiment The second embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, as shown in Fig. 5, a bypass switch 51 connects the positive terminal of the second storage battery 32 to the high-potential-side electrical path 22H. In addition, a motor-side switch 61 connects the negative terminal of the first storage battery 31 to the neutral point of the armature winding 11.

[0045] FIG. 6 shows the procedure of the charge control process executed by the control device 100 in this embodiment.

[0046] If it is determined in step S10 that the external charger is the high-voltage charger 200, the process proceeds to step S14, where the inter-battery switch 40 is turned on and the bypass switch 51, the motor-side switch 61, and the upper and lower arm switches SWH, SWL of all phases of the inverter 20 are turned off so that the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage charger 200. As a result, the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage charger 200, and the first storage battery 31 and the second storage battery 32 are charged in that state.

[0047] If it is determined in step S12 that the external charger is the low-voltage charger 210, the process proceeds to step S15, where the inter-battery switch 40 is turned off, the bypass switch 51 and the motor-side switch 61 are turned on, the lower arm switches SWL of all phases of the inverter 20 are turned off, and the upper arm switch SWH of at least one phase is turned on so that the first storage battery 31 and the second storage battery 32 are connected to the low-voltage charger 210 in an via-motor connection state, thereby charging the first storage battery 31 and the second storage battery 32.

[0048] <Modification of the second embodiment> 6, the lower arm switches SWL of at least one phase and the motor-side switch 61 may be turned on, provided that the upper and lower arm switches SWH, SWL of the same phase of the inverter 20 are not turned on. Also, in step S14, switching may be performed by repeatedly turning on and off either the upper and lower arm switches SWH, SWL of the same phase, or by alternately turning on the upper and lower arm switches SWH, SWL of the same phase.

[0049] In step S15, the lower arm switch SWL is not limited to being kept on, but may be switched on and off repeatedly, or the upper and lower arm switches SWH, SWL may be alternately switched on in at least one phase.

[0050] After the affirmative determination in step S12, the process of step S15 may be performed if it is determined that the second detection voltage VB is equal to or greater than the first detection voltage VA. Alternatively, after the affirmative determination in step S12, the process of step S15 may be performed if it is determined that the first detection voltage VA is higher than the second detection voltage VB and the value obtained by subtracting the second detection voltage VB from the first detection voltage VA is equal to or less than the threshold value ΔVjde.

[0051] Third Embodiment The third embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, as shown in Fig. 7, a bypass switch 80 that connects the positive terminal of the second storage battery 32 and the high-potential-side electrical path 22H is further provided. In this embodiment, the bypass switch 80 will be referred to as the second bypass switch 80, and the bypass switch 50 will be referred to as the first bypass switch 50.

[0052] FIG. 8 shows the procedure of the charging control process executed by the control device 100 according to this embodiment.

[0053] In step S20, similarly to step S10, it is determined whether the external charger is the high-voltage charger 200.

[0054] If it is determined in step S20 that the external charger is the high-voltage charger 200, the process proceeds to step S21, where the inter-battery switch 40, the first bypass switch 50, the second bypass switch 80, the motor-side switch 60, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage charger 200.

[0055] Specifically, the inter-battery switch 40 is turned on, and the first bypass switch 50, the second bypass switch 80, the motor-side switch 60, and the upper and lower arm switches SWH, SWL of all phases of the inverter 20 are turned off. As a result, the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage charger 200, and are charged in that state.

[0056] If it is determined in step S20 that the external charger is not the high-voltage charger 200, the process proceeds to step S22, where it is determined whether the external charger is the low-voltage charger 210, similar to step S12.

[0057] If it is determined in step S22 that the external charger is the low-voltage charger 210, the process proceeds to step S23, where it is determined whether the absolute value of the difference between the first detection voltage VA and the second detection voltage VB is equal to or less than the first threshold value ΔVjde1 (>0).

[0058] If it is determined in step S23 that the absolute value of the difference is equal to or less than the first threshold value ΔVjde1, the process proceeds to step S24, where the inter-battery switch 40, the first bypass switch 50, the second bypass switch 80, the motor-side switch 60, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the first storage battery 31 and the second storage battery 32 are each connected in parallel to the low-voltage charger 210.

[0059] Specifically, the inter-battery switch 40 and the motor-side switch 60 are turned off, and the first bypass switch 50 and the second bypass switch 80 are turned on. Furthermore, the upper and lower arm switches SWH and SWL of all phases of the inverter 20 are turned off. As a result, the first storage battery 31 and the second storage battery 32 are each connected in parallel to the low-voltage charger 210, as shown in FIG. 10 . Therefore, a current flows through a closed circuit including the low-voltage charger 210, the high-potential-side electrical path 22H, the first storage battery 31, the first bypass switch 50, and the low-potential-side electrical path 22L, thereby charging the first storage battery 31. Furthermore, a current flows through a closed circuit including the low-voltage charger 210, the high-potential-side electrical path 22H, the second bypass switch 80, the second storage battery 32, and the low-potential-side electrical path 22L, thereby charging the second storage battery 32. In this case, since the potential difference between the first and second storage batteries 31, 32 is small, it is possible to suppress the occurrence of a phenomenon in which current flows from one of the first and second storage batteries 31, 32 to the other, or to reduce the amount of current that flows even if this phenomenon does occur.

[0060] Returning to the explanation of FIG. 8, if it is determined in step S23 that the absolute value of the difference exceeds the first threshold value ΔVjde1, the process proceeds to step S25, where it is determined whether the value obtained by subtracting the first detection voltage VA from the second detection voltage VB is equal to or less than a second threshold value ΔVjde2 (>0) that is greater than the first threshold value ΔVjde1. If it is determined in step S25 that "VB - VA > ΔVjde2", charging of the first and second storage batteries 31, 32 by the low-voltage charger 210 in the motor-connected state and the parallel-connected state is prohibited. The situation in which it is determined in step S25 that "VB - VA > ΔVjde2" occurs when the second detection voltage VB is higher than the first detection voltage VA and the potential difference between the second detection voltage VB and the first detection voltage VA exceeds the second threshold value ΔVjde2. In addition, the first threshold value ΔVjde1 may be set to a potential difference between the first storage battery 31 and the second storage battery 32 such that, for example, when the first and second storage batteries 31 and 32 are connected in parallel, the maximum value and steady-state value of the inrush current determined from the relationship between the "impedance of the current path between the first storage battery 31 and the second storage battery 32 (specifically, for example, the impedance of the first and second storage batteries 31 and 32)" and the "potential difference between the first storage battery 31 and the second storage battery 32" are below an allowable value. Furthermore, for example, when the connection state of the first and second storage batteries 31, 32 is set to a motor-connection state, the second threshold value ΔVjde2 may be set to a potential difference between the first storage battery 31 and the second storage battery 32 such that the maximum value and steady-state value of the inrush current determined from the relationship between "the impedance of the current path existing between the first storage battery 31 and the second storage battery 32 (specifically, for example, the impedance of the first and second storage batteries 31, 32, the impedance of the inverter 20 and the armature winding 11, and the impedance in the forward direction of the diode of the inverter 20)" and "the potential difference between the first storage battery 31 and the second storage battery 32" are equal to or less than an allowable value. Here, the allowable value is, for example, the maximum current that components on the current path can safely withstand.

[0061] On the other hand, if it is determined in step S25 that "VB - VA ≤ ΔVjde2," the process proceeds to step S26. The determination in step S25 that "VB - VA ≤ ΔVjde2" occurs when the first detection voltage VA is higher than the second detection voltage VB and the potential difference between the second detection voltage VB and the first detection voltage VA exceeds the first threshold value ΔVjde1, or when the second detection voltage VB is higher than the first detection voltage VA and the potential difference between the second detection voltage VB and the first detection voltage VA is greater than the first threshold value ΔVjde1 but equal to or less than the second threshold value ΔVjde2. In step S26, the inter-battery switch 40, the first bypass switch 50, the second bypass switch 80, the motor-side switch 60, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the connection state between the first storage battery 31 and the second storage battery 32 becomes a motor-mediated connection state.

[0062] Specifically, the inter-battery switch 40 and the second bypass switch 80 are turned off, and the first bypass switch 50 and the motor-side switch 60 are turned on. Furthermore, all lower-arm switches SWL of the inverter 20 are turned off, and at least one upper-arm switch SWH of the inverter 20 is turned on. As a result, as shown in FIG. 9 , the first storage battery 31 and the second storage battery 32 are connected via the motor. Therefore, current flows through a closed circuit including the low-voltage charger 210, the high-potential-side electrical path 22H, the first storage battery 31, the first bypass switch 50, and the low-potential-side electrical path 22L, thereby charging the first storage battery 31. Furthermore, current flows through a closed circuit including the low-voltage charger 210, the high-potential-side electrical path 22H, the upper-arm switch SWH, the armature winding 11, the neutral point, the motor-side switch 60, the second storage battery 32, and the low-potential-side electrical path 22L, thereby charging the second storage battery 32. In this case, it is possible to suppress the occurrence of a phenomenon in which current flows from the second storage battery 32 to the first storage battery 31 via the motor side electrical path 25, the upper arm diode DH of the armature winding 11, and the high potential side electrical path 22H, or to reduce the amount of current that flows in even if this phenomenon does occur.

[0063] <Modification of the third embodiment> 8 may be omitted, and step S26 may be performed if the result of step S23 is affirmative. In step S26, the upper arm switch SWH may not be kept on, but may be switched on and off repeatedly, or the upper and lower arm switches SWH, SWL may be alternately turned on in at least one phase.

[0064] <Fourth embodiment> The fourth embodiment will be described below with reference to the drawings, focusing on the differences from the third embodiment. In this embodiment, as shown in Fig. 11, the motor-side electrical path 25, in which the motor-side switch 61 is provided, connects the neutral point of the armature winding 11 to the part of the inter-battery electrical path 24 that is closer to the first storage battery 31 than the inter-battery switch 40.

[0065] FIG. 12 shows the procedure of the charge control process executed by the control device 100 according to this embodiment.

[0066] If it is determined in step S20 that the external charger is the high-voltage charger 200, the process proceeds to step S26, where the inter-battery switch 40, the first bypass switch 50, the second bypass switch 80, the motor-side switch 61, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage charger 200.

[0067] Specifically, the inter-battery switch 40 is turned on, and the first bypass switch 50, the second bypass switch 80, the motor-side switch 61, and the upper and lower arm switches SWH, SWL of all phases of the inverter 20 are turned off. As a result, the first storage battery 31 and the second storage battery 32 are charged in a state in which they are connected in series to the high-voltage charger 200.

[0068] If it is determined in step S22 that the external charger is the low-voltage charger 210, the process proceeds to step S23. If it is determined in step S23 that the absolute value of the difference between the first detected voltage VA and the second detected voltage VB is equal to or less than the first threshold value ΔVjde1, the process proceeds to step S27. In step S27, the inter-battery switch 40, the first bypass switch 50, the second bypass switch 80, the motor-side switch 61, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the first storage battery 31 and the second storage battery 32 are connected in parallel to the low-voltage charger 210.

[0069] Specifically, the inter-battery switch 40 and the motor-side switch 61 are turned off, and the first bypass switch 50 and the second bypass switch 80 are turned on. In addition, the upper and lower arm switches SWH, SWL of all phases of the inverter 20 are turned off. As a result, the first and second storage batteries 31, 32 are charged in a state in which the first and second storage batteries 31, 32 are connected in parallel to the low-voltage charger 210. At this time, because the potential difference between the first and second storage batteries 31, 32 is small, it is possible to suppress the occurrence of a phenomenon in which current flows from one of the first and second storage batteries 31, 32 to the other, or to reduce the amount of current that flows even if this phenomenon does occur.

[0070] If the determination in step S23 is negative, the process proceeds to step S28, where it is determined whether the value obtained by subtracting the second detection voltage VB from the first detection voltage VA is equal to or less than the second threshold value ΔVjde2. If it is determined in step S28 that "VA - VB > ΔVjde2", charging of the first and second storage batteries 31, 32 by the low-voltage charger 210 in the motor-connected state and in the parallel-connected state is prohibited. The situation in which it is determined in step S28 that "VA - VB > ΔVjde2" is one in which the first detection voltage VA is higher than the second detection voltage VB and the potential difference between the second detection voltage VB and the first detection voltage VA exceeds the second threshold value ΔVjde2.

[0071] On the other hand, if it is determined in step S28 that "VA - VB ≤ ΔVjde2," the process proceeds to step S29. The determination in step S28 that "VA - VB ≤ ΔVjde2" occurs when the second detection voltage VB is higher than the second detection voltage VA and the potential difference between the second detection voltage VB and the first detection voltage VA exceeds the first threshold value ΔVjde1, or when the first detection voltage VB is higher than the second detection voltage VB and the potential difference between the second detection voltage VB and the first detection voltage VA is greater than the first threshold value ΔVjde1 and equal to or less than the second threshold value ΔVjde2. In step S29, the inter-battery switch 40, the first bypass switch 50, the second bypass switch 80, the motor-side switch 61, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the connection state between the first storage battery 31 and the second storage battery 32 becomes a motor-mediated connection state.

[0072] Specifically, the inter-battery switch 40 and the first bypass switch 50 are turned off, and the second bypass switch 80 and the motor-side switch 61 are turned on. Also, the upper-arm switches SWH of all phases of the inverter 20 are turned off, and the lower-arm switch SWL of at least one phase is turned on. As a result, the connection state of the first and second storage batteries 31, 32 to the low-voltage charger 210 becomes a motor-directed connection state, and the first and second storage batteries 31, 32 are charged. At this time, it is possible to suppress the occurrence of a phenomenon in which current flows from the first storage battery 31 to the second storage battery 32, or to reduce the amount of current that flows in even if this phenomenon occurs.

[0073] <Modification of the Fourth Embodiment> 12. The process of step S28 may be omitted, and the process of step S29 may be performed when the result of step S23 is affirmative. Furthermore, in step S29, the lower arm switch SWL is not limited to being kept on, but may be switched on and off repeatedly, or the upper and lower arm switches SWH, SWL may be alternately switched on in at least one phase.

[0074] Fifth Embodiment The fifth embodiment will be described below with reference to the drawings, focusing on the differences from the fourth embodiment. In this embodiment, as shown in Fig. 13, in addition to a switch that connects the neutral point of the armature winding 11 to the negative terminal of the first storage battery 31, a switch that connects the neutral point of the armature winding 11 to the positive terminal of the second storage battery 32 is provided as the motor-side switches.

[0075] A first end of the common path 26 is connected to the neutral point of the armature winding 11. A first end of the first electrical path 27 is connected to a second end of the common path 26, and a second end of the first electrical path 27 is connected to a part of the inter-battery electrical path 24 that is closer to the second storage battery 32 than the inter-battery switch 40. A first end of the second electrical path 28 is connected to a second end of the common path 26, and a second end of the second electrical path 28 is connected to a part of the inter-battery electrical path 24 that is closer to the first storage battery 31 than the inter-battery switch 40. In this embodiment, the common path 26 and the first electrical path 27 correspond to the "first motor-side electrical path," and the common path 26 and the second electrical path 28 correspond to the "second motor-side electrical path." Note that the common path 26 may not be provided, and the first ends of the first electrical path 27 and the second electrical path 28 may each be connected to the neutral point of the armature winding 11.

[0076] A first motor-side switch 60 is provided on the first electrical path 27. A second motor-side switch 61 is provided on the second electrical path .

[0077] FIG. 14 shows the procedure of the charge control process executed by the control device 100 in this embodiment.

[0078] If it is determined in step S20 that the external charger is the high-voltage charger 200, the process proceeds to step S30, where the inter-battery switch 40 is turned on and the first bypass switch 50, the second bypass switch 80, the first motor-side switch 60, the second motor-side switch 61, and the upper and lower arm switches SWH, SWL of the inverter 20 are turned off so that the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage charger 200. As a result, the first storage battery 31 and the second storage battery 32 are charged in a state in which they are connected in series to the high-voltage charger 200.

[0079] If it is determined in step S22 that the external charger is the low-voltage charger 210, the process proceeds to step S23. If it is determined in step S23 that the absolute value of the difference between the first detected voltage VA and the second detected voltage VB is equal to or less than the first threshold value ΔVjde1, the process proceeds to step S31. In step S31, the inter-battery switch 40, the first bypass switch 50, the second bypass switch 80, the first motor-side switch 60, the second motor-side switch 61, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the first storage battery 31 and the second storage battery 32 are connected in parallel to the low-voltage charger 210.

[0080] Specifically, the inter-battery switch 40, the first motor-side switch 60, and the second motor-side switch 61 are turned off, and the first bypass switch 50 and the second bypass switch 80 are turned on. In addition, the upper and lower arm switches SWH, SWL of all phases of the inverter 20 are turned off. As a result, the first and second storage batteries 31, 32 are charged in a state in which the first and second storage batteries 31, 32 are connected in parallel to the low-voltage charger 210. At this time, because the potential difference between the first and second storage batteries 31, 32 is small, it is possible to suppress the occurrence of a phenomenon in which current flows from one of the first and second storage batteries 31, 32 to the other, or to reduce the amount of current that flows even if this phenomenon does occur.

[0081] If the determination in step S23 is negative, the process proceeds to step S34, where it is determined which of the first detected voltage VA and the second detected voltage VB is higher. If the determination in step S34 is that "VA>VB", the process proceeds to step S32, where the inter-battery switch 40, the first bypass switch 50, the second bypass switch 80, the first motor-side switch 60, the second motor-side switch 61, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the connection state between the first storage battery 31 and the second storage battery 32 becomes a connection state via the first motor.

[0082] Specifically, the inter-battery switch 40, the second motor-side switch 61, and the second bypass switch 80 are turned off, and the first bypass switch 50 and the first motor-side switch 60 are turned on. Also, the lower arm switches SWL of all phases of the inverter 20 are turned off, and the upper arm switch SWH of at least one phase is turned on. This charges the first and second storage batteries 31, 32. At this time, because the potential difference between the first and second storage batteries 31, 32 is small, it is possible to suppress the occurrence of a phenomenon in which current flows from the second storage battery 32 to the first storage battery 31, or to reduce the amount of current that flows even if this phenomenon does occur.

[0083] On the other hand, if it is determined in step S34 that "VB>VA", the process proceeds to step S33, and the inter-battery switch 40, the first bypass switch 50, the second bypass switch 80, the first motor side switch 60, the second motor side switch 61, and the upper and lower arm switches SWH, SWL of the inverter 20 are operated so that the connection state between the first storage battery 31 and the second storage battery 32 becomes a connection state via the second motor.

[0084] Specifically, the inter-battery switch 40, the first motor-side switch 60, and the first bypass switch 50 are turned off, and the second bypass switch 80 and the second motor-side switch 61 are turned on. Also, the upper arm switches SWH of all phases of the inverter 20 are turned off, and the lower arm switch SWL of at least one phase is turned on. This charges the first and second storage batteries 31, 32. At this time, because the potential difference between the first and second storage batteries 31, 32 is small, it is possible to suppress the occurrence of a phenomenon in which current flows from the first storage battery 31 to the second storage battery 32, or to reduce the amount of current that flows in even if this phenomenon does occur.

[0085] According to the present embodiment described above, it is possible to suppress or reduce the flow of current from one of the first and second storage batteries 31, 32 to the other, regardless of the magnitude relationship between the terminal voltages of the first storage battery 31 and the second storage battery 32. Note that in step S32 of Fig. 14, the upper arm switch SWH is not limited to being kept on, but may be switched on and off repeatedly, or the upper and lower arm switches SWH, SWL may be switched on alternately in at least one phase. Also, in step S33, the lower arm switch SWL is not limited to being kept on, but may be switched on and off repeatedly, or the upper and lower arm switches SWH, SWL may be switched on alternately in at least one phase.

[0086] Sixth Embodiment The sixth embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, during charging when the low-voltage charger 210 is connected, switching is performed in which the upper arm switch SWH included in the charging path of the second storage battery 32 is repeatedly turned on and off. In this case, a high-frequency current is generated due to the switching. In this embodiment, as shown in FIG. 15 , the power conversion device is provided with a capacitor 90 that suppresses the high-frequency current generated due to the switching from flowing from the inverter 20 side to the second storage battery 32 and the low-voltage charger 210.

[0087] A portion of the low potential side electrical path 22L (corresponding to the "target path") between the low potential side main switch SMRL and the low potential side charging switch DCRL is connected to the neutral point side of the motor side switch 60 in the motor side electrical path 25 via a series connection of a connection switch 91 and a capacitor 90. The connection switch 91 may be a mechanical relay or a semiconductor switching element.

[0088] The control device 100 turns off the connection switch 91 during switching control of the inverter 20 for running the vehicle. This makes it possible to prevent adverse effects on the control of the control amount of the motor 10 to the command value.

[0089] 2, for example, during the charging process by the low-voltage charger 210. This allows noise or ripple contained in the current flowing through the motor-side electrical path 25 to flow to the capacitor 90 when a current flows through the motor-side electrical path 25. On the other hand, for example, during the charging process by the high-voltage charger 200 in step S11, the control device 100 turns off the connection switch 91. This is because no switching of the inverter 20 is performed during the charging process by the high-voltage charger 200.

[0090] According to the present embodiment described above, during charging processing by the low-voltage charger 210, high-frequency current generated by switching can be prevented from flowing from the inverter 20 side into the second storage battery 32 and the low-voltage charger 210.

[0091] <Modification of the Sixth Embodiment> The capacitor 90 may be connected to the motor-side electrical path 25 side, and the connection switch 91 may be connected to the low-potential-side electrical path 22L side.

[0092] The connection switch 91 may be omitted. In other words, the motor-side electrical path 25 and the low-potential-side electrical path 22L may be constantly connected.

[0093] As shown in FIG. 16, a series connection of a connection switch 92 and a capacitor 90 may connect a portion of the motor-side electrical path 25 that is closer to the second storage battery 32 than the motor-side switch 60 to the low-potential-side electrical path 22L.

[0094] 16, the connection switch 92 may be omitted. That is, the motor-side electrical path 25 and the low-potential-side electrical path 22L may be constantly connected.

[0095] 17, a plurality of capacitors may be provided. More specifically, a connection switch 93 is provided on the motor-side electrical path 25 closer to the neutral point than the motor-side switch 60. A high-potential-side electrical path 22H (corresponding to the "target path") is connected to a portion of the motor-side electrical path 25 between the motor-side switch 60 and the connection switch 93 via a first capacitor 93A, and a low-potential-side electrical path 22L (corresponding to the "target path") is connected to the portion of the motor-side electrical path 25 between the motor-side switch 60 and the connection switch 93 via a second capacitor 93B.

[0096] In the configuration shown in FIG. 17, either the first capacitor 93A or the second capacitor 93B may be omitted.

[0097] As shown in FIG. 18, a first terminal of a connection switch 94 may be connected to a position on the motor-side electrical path 25 closer to the neutral point than the motor-side switch 60, and a first capacitor 93A and a second capacitor 93B may be connected to a second terminal of the connection switch 94.

[0098] Seventh Embodiment The seventh embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. As shown in Fig. 19, a series connection of a pre-charge switch SP and a resistor 95 is connected in parallel to a motor-side switch 60. For convenience, the control device 100 and other components are not shown in Fig. 19.

[0099] For example, when the power conversion device is started up, the control device 100 performs a precharge process to charge the smoothing capacitor 21. In this embodiment, even if an abnormality occurs in either the first storage battery 31 or the second storage battery 32 and the battery becomes unusable, the precharge process can be performed using the remaining storage battery.

[0100] First, referring to Figure 20, a case where an abnormality occurs in the second storage battery 32 will be described. In this case, the control device 100 turns on the high potential side main switch SMRH, the pre-charge switch SP, and the inter-battery switch 40, and turns off the low potential side main switch SMRL, the motor side switch 60, and the bypass switch 50. The control device 100 also turns off the upper and lower arm switches SWH, SWL of all phases of the inverter 20. This allows the smoothing capacitor 21 to be charged by the first storage battery 31.

[0101] Next, a case where an abnormality occurs in the first storage battery 31 will be described with reference to Fig. 21. In this case, the control device 100 turns on the low potential side main switch SMRL and the pre-charge switch SP, and turns off the high potential side main switch SMRH, the motor side switch 60, the inter-battery switch 40, and the bypass switch 50. The control device 100 also turns off the upper and lower arm switches SWH, SWL of all phases of the inverter 20. This allows the smoothing capacitor 21 to be charged by the second storage battery 32.

[0102] Eighth Embodiment The eighth embodiment will be described below with reference to the drawings, focusing on the differences from the sixth and seventh embodiments. In this embodiment, as shown in Fig. 22, a connection switch 93 and a capacitor 90 are provided. A first end of the capacitor 90 is connected to a portion of the motor-side electrical path 25 between the connection point with the pre-charge switch SP and the connection switch 92. A second end of the capacitor 90 is connected to the low-potential-side electrical path 22L on the inverter 20 side relative to the low-potential-side main switch SMRL.

[0103] In the precharge process for charging the smoothing capacitor 21, the control device 100 can simultaneously charge the smoothing capacitor 21 and the capacitor 90. Specifically, as shown in Fig. 23 , the control device 100 turns on the high potential side main switch SMRH, the precharge switch SP, and the inter-battery switch 40, and turns off the low potential side main switch SMRL, the motor side switch 60, and the bypass switch 50. The control device 100 also turns off the upper and lower arm switches SWH, SWL of all phases of the inverter 20.

[0104] <Modification of the Eighth Embodiment> As shown in FIG. 24, a series connection of a precharge switch SP and a resistor 95 may be connected in parallel to the low-potential side main switch SMRL.

[0105] <Other embodiments> The above-described embodiments may be modified as follows.

[0106] The circuit configuration of the power conversion device of each of the above embodiments can be modified as follows, for example: (A) to (J).

[0107] (A) As shown in FIG. 25, the motor-side switch 60 may be omitted in the configuration shown in FIG.

[0108] (B) As shown in FIG. 26, the motor-side switch 61 may be omitted from the configuration shown in FIG.

[0109] (C) As shown in FIG. 27, the motor-side switch 60 may be omitted in the configuration shown in FIG.

[0110] (D) As shown in FIG. 28, the motor-side switch 61 may be omitted in the configuration shown in FIG.

[0111] (E) As shown in Fig. 29, the first motor-side switch 60 may be omitted from the configuration shown in Fig. 13. In this case, if a negative determination is made in step S34 of Fig. 14, charging by the low-voltage charger 210 in the motor-interface connection state may be prohibited.

[0112] (F) As shown in Fig. 30, the second motor-side switch 61 may be omitted from the configuration shown in Fig. 13. In this case, if a positive determination is made in step S34 of Fig. 14, charging by the low-voltage charger 210 in the motor-via-connection state may be prohibited.

[0113] (G) As shown in FIG. 31, the first motor-side switch 60 and the second bypass switch 80 may be omitted from the configuration shown in FIG.

[0114] (H) As shown in FIG. 32, the second bypass switch 80 may be omitted from the configuration shown in FIG.

[0115] (I) As shown in FIG. 33, the second motor-side switch 61 and the first bypass switch 50 may be omitted from the configuration shown in FIG.

[0116] (J) As shown in FIG. 34, the first bypass switch 50 may be omitted from the configuration shown in FIG.

[0117] 35, the positive terminal of the first storage battery 31 and the high potential side electrical path 22H may be connected by a first fuse 110A. Also, the negative terminal of the second storage battery 32 and the low potential side electrical path 22L may be connected by a second fuse 110B.

[0118] As shown in FIG. 36 , a third current sensor 75 may be provided in a portion of the high-potential-side electrical path 22H between the connection point with the first storage battery 31 and the high-potential-side charging switch DCRH. A fourth current sensor 76 may be provided at any position in the motor-side electrical path 25. For example, the fourth current sensor 76 may be provided on the motor-side electrical path 25 closer to the neutral point than the motor-side switch 60. It is sufficient to provide at least two of the first to fourth current sensors 73 to 76. This enables charging control of the storage batteries 31, 32 using as few current sensors as possible. A current sensor may be provided to detect the current flowing through each conductive member 23, and the sum of the detected values ​​of the currents flowing through the conductive members 23 may be used instead of the detected value of the fourth current sensor.

[0119] The connection destination of the motor-side electrical path 25 is not limited to the neutral point of the armature winding 11, but may be, for example, a middle portion of the armature winding 11 as shown in FIG.

[0120] Furthermore, the connection destination of the motor-side electrical path 25 may be, for example, the conductive member 23 as shown in Fig. 38. In this case, in the charging process by the low-voltage charger 210, the upper arm switch SWH of each phase other than the phase to which the motor-side electrical path 25 is connected to the conductive member 23 may be turned on and the lower arm switch SWL may be turned off as shown in Fig. 39.

[0121] As shown in FIG. 40, a high potential side charging switch DCRH and a positive electrode side connection part may be provided on the high potential side electrical path 22H on the side opposite the first storage battery 31 side with respect to the inverter 20, and a low potential side charging switch DCRL and a negative electrode side connection part may be provided on the low potential side electrical path 22L on the side opposite the second storage battery 32 side with respect to the inverter 20.

[0122] 41, one end of the capacitor 90 may be connected to the motor-side electrical path 25 closer to the second storage battery 32 than the motor-side switch 60. In this case, the connection switch is not required.

[0123] The main switches SMRH, SMRL, charging switches DCRH, DCRL, inter-battery switch 40, bypass switch, motor-side switch, and connection switch are not limited to being composed of a single switch, but may be composed of a series connection of multiple switches or a parallel connection of multiple switches.

[0124] The switches of the inverter 20 are not limited to IGBTs, but may be, for example, N-channel MOSFETs with body diodes. In this case, the high-potential side terminal of the N-channel MOSFET becomes the drain, and the low-potential side terminal becomes the source.

[0125] The motor is not limited to a star-connected one, but may be a delta-connected one. The motor and inverter are not limited to a three-phase one, but may be a two-phase one, or four or more phases. The motor is not limited to a permanent magnet synchronous machine having a permanent magnet as a field pole on the rotor, but may be a wound field synchronous machine having a field winding as a field pole on the rotor. In this case, the rotor may be provided with both a field winding and a permanent magnet. The motor is not limited to a synchronous machine, but may be an induction machine.

[0126] The power storage unit to be charged by the external charger is not limited to a storage battery, but may be, for example, a large-capacity electric double layer capacitor, or one that includes both a storage battery and an electric double layer capacitor.

[0127] The mobile body on which the power conversion device is mounted is not limited to a vehicle, but may be, for example, an aircraft or a ship.Furthermore, the power conversion device is not limited to a mobile body, but may be a stationary device.

[0128] The control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium.

[0129] The following describes characteristic configurations extracted from the above-described embodiments. [Configuration 1] a high-potential side electrical path (22H) electrically connectable to a positive electrode terminal of the first power storage unit (31); a low potential side electrical path (22L) electrically connectable to a negative electrode terminal of the second power storage unit (32); an inverter (20) having an upper arm switch (SWH) electrically connected to the high potential side electrical path and a lower arm switch (SWL) electrically connected to the low potential side electrical path; a motor (10) having an armature winding (11) electrically connected to a connection point between the upper arm switch and the lower arm switch via a conductive member (23); In a power conversion device comprising: an inter-power storage unit switch (40) provided in an inter-power storage unit electrical path (24) that electrically connects the negative electrode terminal of the first power storage unit and the positive electrode terminal of the second power storage unit; a bypass switch (50, 51) that electrically connects at least one of the negative electrode terminals of the first power storage unit and the second power storage unit and the positive electrode terminals of the first power storage unit and the second power storage unit; a motor-side electrical path (25-28) electrically connecting the armature winding or the conductive member to the electrical path between the power storage units; A power conversion device comprising: [Configuration 2] the bypass switch (50) is a switch that electrically connects the negative electrode terminal of the first power storage unit and the negative electrode terminal of the second power storage unit, the motor-side electrical path (25) electrically connects the armature winding to a portion of the inter-energy-storage-unit electrical path that is closer to the second energy storage unit than the inter-energy-storage-unit switch, 2. The power conversion device according to claim 1, further comprising a motor-side switch (60) provided in the motor-side electrical path. [Configuration 3] a control unit (100) that determines whether a connection state of the first power storage unit and the second power storage unit should be a series connection state or a motor-via-connection state in which a positive electrode terminal of the second power storage unit is connected to the motor-side electrical path, the armature winding, and the inverter via the high-potential-side electrical path, The control unit when it is determined that the connection state of the first power storage unit and the second power storage unit should be the series connection state, turning on the inter-power storage unit switch and turning off the bypass switch; the power conversion device according to configuration 2, wherein, on condition that it is determined that the connection state of the first power storage unit and the second power storage unit is to be the motor-via-connection state, the power storage unit switch is turned off and the bypass switch and the motor-side switch are turned on. [Configuration 4] the bypass switch is a first bypass switch (50), The power conversion device according to configuration 2, further comprising a second bypass switch (80) that electrically connects the positive electrode terminal of the first power storage unit and the positive electrode terminal of the second power storage unit. [Configuration 5] a control unit (100) that determines whether a connection state of the first power storage unit and the second power storage unit should be a series connection state, a parallel connection state, or a motor-via-connection state in which a positive electrode terminal of the second power storage unit is connected to the motor-side electrical path, the armature winding, and the inverter via the high-potential-side electrical path; The control unit when it is determined that the connection state of the first power storage unit and the second power storage unit should be the series connection state, turning on the inter-power storage unit switch and turning off the first bypass switch and the second bypass switch; performing a first operation when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the parallel connection state; performing a second operation when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the motor-via-connection state; the first operation is an operation of turning off the inter-power-storage unit switch and the motor-side switch and turning on the first bypass switch and the second bypass switch, the second operation is an operation of turning off the inter-power-storage unit switch and the second bypass switch, turning on the first bypass switch and the motor-side switch, and performing a switch operation on the inverter, The power conversion device described in configuration 4, wherein the switch operation of the inverter is an operation of turning off the lower arm switches of each phase and turning on the upper arm switches of at least one phase, or an operation of repeatedly turning on and off the upper arm switches of at least one phase, provided that the upper and lower arm switches of the same phase are not turned on simultaneously. [Configuration 6] The control unit performing the first operation when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the parallel connection state and when it is determined that the potential difference between the first power storage unit and the second power storage unit is equal to or smaller than a first threshold value (ΔVjde1); The power conversion device of configuration 5 performs the second operation when it determines that the connection state of the first storage unit and the second storage unit should be changed to the motor-via-connection state and determines that the value obtained by subtracting the voltage of the first storage unit from the voltage of the second storage unit is equal to or less than a second threshold (ΔVjde2) that is greater than the first threshold. [Configuration 7] the bypass switch (51) is a switch that electrically connects a positive electrode terminal of the first power storage unit and a positive electrode terminal of the second power storage unit, the motor-side electrical path (25) electrically connects the armature winding to a portion of the inter-energy-storage-unit electrical path that is closer to the first energy storage unit than the inter-energy-storage-unit switch, 2. The power conversion device according to claim 1, further comprising a motor-side switch (61) provided in the motor-side electrical path. [Configuration 8] a control unit (100) that determines whether a connection state of the first power storage unit and the second power storage unit should be a series connection state or a motor-via-connection state in which a negative electrode terminal of the first power storage unit is connected to the motor-side electrical path, the armature winding, and the inverter via the low-potential-side electrical path, The control unit when it is determined that the connection state of the first power storage unit and the second power storage unit should be the series connection state, turning on the inter-power storage unit switch and turning off the bypass switch; the power conversion device according to configuration 7, wherein, on condition that it is determined that the connection state of the first power storage unit and the second power storage unit is to be the motor-via-connection state, the power storage unit-to-power storage unit switch is turned off and the bypass switch and the motor-side switch are turned on. [Configuration 9] a first bypass switch (50) that electrically connects a negative terminal of the first power storage unit and a negative terminal of the second power storage unit; a second bypass switch (80) that electrically connects the positive electrode terminal of the first power storage unit and the positive electrode terminal of the second power storage unit; Equipped with the motor-side electrical path (25) electrically connects the armature winding to a portion of the inter-energy-storage-unit electrical path that is closer to the first energy storage unit than the inter-energy-storage-unit switch, 2. The power conversion device according to claim 1, further comprising a motor-side switch (61) provided in the motor-side electrical path. [Configuration 10] a control unit (100) that determines whether a connection state of the first power storage unit and the second power storage unit should be a series connection state, a parallel connection state, or a motor-via-connection state in which a negative electrode terminal of the first power storage unit is connected to the motor-side electrical path, the armature winding, and the inverter via the low-potential-side electrical path, The control unit when it is determined that the connection state of the first power storage unit and the second power storage unit should be the series connection state, turning on the inter-power storage unit switch and turning off the first bypass switch and the second bypass switch; performing a first operation when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the parallel connection state; performing a second operation when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the motor-via-connection state; the first operation is an operation of turning off the inter-power-storage unit switch and the motor-side switch and turning on the first bypass switch and the second bypass switch, the second operation is an operation of turning off the inter-power-storage unit switch and the first bypass switch, turning on the second bypass switch and the motor-side switch, and performing a switch operation on the inverter, The power conversion device described in configuration 9, wherein the switch operation of the inverter is an operation of turning off the upper arm switch of each phase and turning on the lower arm switch of at least one phase, or an operation of repeatedly turning on and off the lower arm switch of at least one phase, provided that the upper and lower arm switches of the same phase are not turned on simultaneously. [Configuration 11] The control unit performing the first operation when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the motor-connection state and when it is determined that the potential difference between the first power storage unit and the second power storage unit is equal to or smaller than a first threshold value (ΔVjde1); The power conversion device of configuration 10 performs the second operation when it determines that the connection state of the first storage unit and the second storage unit should be changed to the motor-via connection state and determines that the value obtained by subtracting the voltage of the second storage unit from the voltage of the first storage unit is equal to or less than a second threshold (ΔVjde2) that is greater than the first threshold. [Configuration 12] The bypass switch includes: a first bypass switch (50) that electrically connects a negative terminal of the first power storage unit and a negative terminal of the second power storage unit; a second bypass switch (80) that electrically connects the positive electrode terminal of the first power storage unit and the positive electrode terminal of the second power storage unit; Equipped with The motor side electrical path is: a first motor-side electrical path (26, 27) electrically connecting the armature winding to a portion of the inter-energy-storage unit electrical path that is closer to the second energy storage unit than the inter-energy-storage unit switch; a second motor-side electrical path (26, 28) electrically connecting the armature winding to a portion of the inter-energy-storage unit electrical path that is closer to the first energy storage unit than the inter-energy-storage unit switch; Equipped with a first motor side switch (60) provided in the first motor side electrical path; a second motor side switch (61) provided in the second motor side electrical path; 2. The power conversion device of claim 1, comprising: [Configuration 13] a control unit (100) that determines whether a connection state of the first power storage unit and the second power storage unit should be a series connection state, a parallel connection state, or a motor-via-connection state in which a positive electrode terminal of the second power storage unit is connected to the high-potential side electrical path via the motor-side electrical path, the armature winding, and the inverter, or a negative electrode terminal of the first power storage unit is connected to the low-potential side electrical path via the motor-side electrical path, the armature winding, and the inverter, The control unit when it is determined that the connection state of the first power storage unit and the second power storage unit should be the series connection state, turning on the inter-power storage unit switch and turning off the first bypass switch and the second bypass switch; performing a first operation when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the parallel connection state; performing a second operation or a third operation when it is determined that the connection state of the first power storage unit and the second power storage unit is to be changed to the motor-connection state; the first operation is an operation of turning off at least one of the first motor-side switch and the second motor-side switch and the power-storage unit switch, and turning on the first bypass switch and the second bypass switch, the second operation is an operation of turning off the inter-energy-storage unit switch, the second bypass switch, and the second motor-side switch, turning on the first bypass switch and the first motor-side switch, and performing a first switch operation of the inverter, the third operation is an operation of turning off the inter-energy storage unit switch, the first bypass switch, and the first motor-side switch, turning on the second bypass switch and the second motor-side switch, and performing a second switch operation of the inverter, the first switch operation of the inverter is an operation of turning off the lower arm switches of each phase and turning on the upper arm switch of at least one phase, or an operation of repeatedly turning on and off the upper arm switch of at least one phase on the condition that the upper and lower arm switches of the same phase are not turned on simultaneously; A power conversion device as described in configuration 12, wherein the second switch operation of the inverter is an operation of turning off the upper arm switches of each phase and turning on the lower arm switches of at least one phase, or an operation of repeatedly turning on and off the lower arm switches of at least one phase, provided that the upper and lower arm switches of the same phase are not turned on simultaneously. [Configuration 14] The control unit performing the first operation when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the motor-connection state and when it is determined that the potential difference between the first power storage unit and the second power storage unit is equal to or smaller than a first threshold value (ΔVjde1); performing the second operation when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the motor-via-connection state and when it is determined that the voltage of the first power storage unit is higher than the voltage of the second power storage unit; The power conversion device according to configuration 13, wherein the third operation is performed when it is determined that the connection state of the first power storage unit and the second power storage unit should be changed to the motor-via-connection state and when it is determined that the voltage of the second power storage unit is higher than the voltage of the first power storage unit. [Configuration 15] The positive terminal of the charger (200, 210) can be electrically connected to the high-potential side electrical path, a negative terminal of the charger can be electrically connected to the low-potential side electrical path, The control unit When the charger connected to the high-potential side electrical path and the low-potential side electrical path is a high-voltage charger (200), it is determined that the connection state of the first power storage unit and the second power storage unit is to be a series connection state; The power conversion device according to any one of configurations 3, 5, 6, 8, 10, and 11, wherein the device determines that the connection state of the first power storage unit and the second power storage unit is to be the motor-via connection state, on the condition that the charger connected to the high-potential side electrical path and the low-potential side electrical path is a low-voltage charger (210) having a charging voltage lower than that of the high-voltage charger. [Configuration 16] The positive terminal of the charger (200, 210) can be electrically connected to the high-potential side electrical path, a negative terminal of the charger can be electrically connected to the low-potential side electrical path, The control unit When the charger connected to the high-potential side electrical path and the low-potential side electrical path is a high-voltage charger (200), it is determined that the connection state of the first power storage unit and the second power storage unit is to be a series connection state; The power conversion device according to configuration 13 or 14, wherein, on the condition that the chargers connected to the high-potential side electrical path and the low-potential side electrical path are low-voltage chargers (210) having a charging voltage lower than that of the high-voltage charger, it is determined that the connection state of the first storage unit and the second storage unit is to be the first motor-via-connection state or the second motor-via-connection state. [Configuration 17] The power conversion device according to any one of configurations 1 to 16, further comprising a capacitor (90, 93A, 93B) that electrically connects a target path, which is at least one of the high-potential side electrical path and the low-potential side electrical path, to the motor-side electrical path. [Configuration 18] The power conversion device of configuration 17 is provided with a connection switch (91-94) that, when turned on, electrically connects the target path and the motor-side electrical path via the capacitor, and, when turned off, cuts off the electrical connection between the capacitor and at least one of the target path and the motor-side electrical path. [Configuration 19] 19. The power conversion device according to configuration 18, wherein the connection switch is turned on when it is determined that a current is to flow through the motor-side electrical path. [Configuration 20] a smoothing capacitor (21) electrically connecting the high-potential side electrical path and the low-potential side electrical path and smoothing the input voltage of the inverter; A series connection of a switch (SP) and a resistor (95); Equipped with the capacitor electrically connects the target path to the armature winding side of the motor-side electrical path relative to the motor-side switch (60); 20. The power conversion device according to any one of configurations 1 to 19, wherein the series-connected body is connected in parallel to the motor-side switch. [Configuration 21] a smoothing capacitor (21) electrically connecting the high-potential side electrical path and the low-potential side electrical path and smoothing the input voltage of the inverter; A series connection of a switch (SP) and a resistor (95); Equipped with 20. The power conversion device according to any one of configurations 1 to 19, wherein the series-connected body is connected in parallel to a motor-side switch (60) provided in the motor-side electrical path.

[0130] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0131] 10...motor, 11...armature winding, 20...inverter, 22H...high potential side electrical path, 22L...low potential side electrical path, 24...inter-battery electrical path, 25...motor side electrical path, 31, 32...first and second storage batteries, 40...inter-battery switch, 50...bypass switch

Claims

1. a high-potential side electrical path (22H) electrically connectable to a positive electrode terminal of the first storage unit (31); a low-potential side electrical path (22L) electrically connectable to a negative electrode terminal of the second power storage unit (32); an inverter (20) having an upper arm switch (SWH) electrically connected to the high potential side electrical path and a lower arm switch (SWL) electrically connected to the low potential side electrical path; a motor (10) having an armature winding (11) electrically connected to a connection point of the upper arm switch and the lower arm switch via a conductive member (23); a first current sensor (73) that detects a current flowing in the first storage unit; a second current sensor (74) that detects a current flowing in the second storage unit; In a power conversion device comprising: an inter-storage unit electrical path (24) that electrically connects the negative electrode terminal of the first storage unit and the positive electrode terminal of the second storage unit; a motor-side electrical path (25-28) electrically connecting the armature winding and the electrical path between the power storage units; a motor-side switch (60) provided in the motor-side electrical path; Equipped with When the motor-side switch is turned off, the first and second power storage units are electrically disconnected from the armature windings, When the motor-side switch is turned on, the second power storage unit and the armature winding are electrically connected to each other.

2. the power conversion device includes an inter-power storage unit switch (40) provided in the inter-power storage unit electrical path, 2. The power conversion device according to claim 1, wherein the motor-side electrical path (25 to 27) is a path that electrically connects the armature winding and a portion of the inter-storage unit electrical path between the inter-storage unit switch and a positive terminal of the second storage unit.

3. The power conversion device includes a bypass switch (50) that electrically connects negative electrode terminals of the first power storage unit and the second power storage unit, the motor-side switch is turned off, the inter-power storage unit switch is turned on, and the bypass switch is turned off, so that the first power storage unit and the second power storage unit are connected in series; 3. The power conversion device according to claim 2, wherein when the motor-side switch is turned on, the inter-power storage unit switch is turned off, and the bypass switch is turned on, a connection state of the first power storage unit and the second power storage unit is such that a positive terminal of the second power storage unit is connected to the high-potential-side electrical path via the motor-side electrical path, the armature winding, and the inverter.

4. a high-potential side electrical path (22H) electrically connectable to a positive electrode terminal of the first storage unit (31); a low-potential side electrical path (22L) electrically connectable to a negative electrode terminal of the second power storage unit (32); an inverter (20) having an upper arm switch (SWH) electrically connected to the high potential side electrical path and a lower arm switch (SWL) electrically connected to the low potential side electrical path; a motor (10) having an armature winding (11) electrically connected to a connection point of the upper arm switch and the lower arm switch via a conductive member (23); a first current sensor (73) that detects a current flowing in the first storage unit; a second current sensor (74) that detects a current flowing in the second storage unit; In a power conversion device comprising: an inter-storage unit electrical path (24) that electrically connects the negative electrode terminal of the first storage unit and the positive electrode terminal of the second storage unit; a motor-side electrical path (25-28) electrically connecting the armature winding and the electrical path between the power storage units; a motor-side switch (61) provided in the motor-side electrical path; Equipped with When the motor-side switch is turned off, the first and second power storage units are electrically disconnected from the armature windings, When the motor-side switch is turned on, the first power storage unit and the armature winding are electrically connected to each other.

5. the power conversion device includes an inter-power storage unit switch (40) provided in the inter-power storage unit electrical path, 5. The power conversion device according to claim 4, wherein the motor-side electrical path (25, 26, 28) is a path that electrically connects the armature winding to a portion of the inter-energy storage unit electrical path between the inter-energy storage unit switch and a negative terminal of the first energy storage unit.

6. The power conversion device includes a bypass switch (51) that electrically connects positive electrode terminals of the first power storage unit and the second power storage unit, the motor-side switch is turned off, the inter-power storage unit switch is turned on, and the bypass switch is turned off, so that the first power storage unit and the second power storage unit are connected in series; 6. The power conversion device according to claim 5, wherein when the motor-side switch is turned on, the inter-power storage unit switch is turned off, and the bypass switch is turned on, a connection state of the first power storage unit and the second power storage unit is brought into a state where a negative terminal of the first power storage unit is connected to the low potential side electrical path via the motor-side electrical path, the armature winding, and the inverter.

7. 5 . The power conversion device according to claim 1 , wherein charging of the first power storage unit and the second power storage unit is controlled using the current detected by the first current sensor and the current detected by the second current sensor.

8. the first current sensor is provided between a positive electrode terminal of the first power storage unit and the high-potential side electrical path; The power conversion device according to claim 1 , wherein the second current sensor is provided between a negative electrode terminal of the second power storage unit and the low-potential side electrical path.

9. The power conversion device is a first voltage sensor (71) for detecting a voltage between the terminals of the first storage unit; a second voltage sensor (72) that detects a voltage between the terminals of the second power storage unit; The power conversion device according to claim 1 or 4, comprising:

10. 10. The power conversion device according to claim 9, wherein, in charging control of the first power storage unit and the second power storage unit, different processes are executed depending on a comparison result between a terminal-to-terminal voltage of the first power storage unit detected by the first voltage sensor and a terminal-to-terminal voltage of the second power storage unit detected by the second voltage sensor.

11. The power conversion device according to claim 1 , wherein the motor-side electrical path electrically connects a neutral point of the armature winding and the electrical path between the power storage units.

12. a high-potential side electrical path (22H) electrically connectable to a positive electrode terminal of the first storage unit (31); a low-potential side electrical path (22L) electrically connectable to a negative electrode terminal of the second power storage unit (32); an inverter (20) having an upper arm switch (SWH) electrically connected to the high potential side electrical path and a lower arm switch (SWL) electrically connected to the low potential side electrical path; a motor (10) having an armature winding (11) electrically connected to a connection point of the upper arm switch and the lower arm switch via a conductive member (23); a first current sensor (73) that detects a current flowing in the first storage unit; a second current sensor (74) that detects a current flowing in the second storage unit; A computer (101); A program applied to a power conversion device comprising: The power conversion device is an inter-storage unit electrical path (24) that electrically connects the negative electrode terminal of the first storage unit and the positive electrode terminal of the second storage unit; a motor-side electrical path (25-28) electrically connecting the armature winding and the electrical path between the power storage units; a motor-side switch (60) provided in the motor-side electrical path; Equipped with The computer, a process of turning off the motor-side switch to electrically disconnect the first and second power storage units from the armature windings; a process of electrically connecting the second power storage unit and the armature winding by turning on the motor-side switch; A program that performs the following.

13. a high-potential side electrical path (22H) electrically connectable to a positive electrode terminal of the first storage unit (31); a low-potential side electrical path (22L) electrically connectable to a negative electrode terminal of the second power storage unit (32); an inverter (20) having an upper arm switch (SWH) electrically connected to the high potential side electrical path and a lower arm switch (SWL) electrically connected to the low potential side electrical path; a motor (10) having an armature winding (11) electrically connected to a connection point of the upper arm switch and the lower arm switch via a conductive member (23); a first current sensor (73) that detects a current flowing in the first storage unit; a second current sensor (74) that detects a current flowing in the second storage unit; A computer (101); A program applied to a power conversion device comprising: The power conversion device is an inter-storage unit electrical path (24) that electrically connects the negative electrode terminal of the first storage unit and the positive electrode terminal of the second storage unit; a motor-side electrical path (25-28) electrically connecting the armature winding and the electrical path between the power storage units; a motor-side switch (61) provided in the motor-side electrical path; Equipped with The computer, a process of turning off the motor-side switch to electrically disconnect the first and second power storage units from the armature windings; a process of electrically connecting the first power storage unit and the armature winding by turning on the motor-side switch; A program that performs the following.

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