Power converter, program

Abstract

This power conversion device comprises: a high-potential-side path (22H) that electrically connects a positive electrode terminal of a first power storage unit (31) and a high-potential-side terminal of an upper arm switch (SWH) of an inverter (20); a low-potential-side path (22L) that electrically connects a negative electrode terminal of a second power storage unit (32) and a low-potential-side terminal of a lower arm switch (SWL); a connection path (73); neutral capacitors (74, 75); parameter detection units (85, 84, 84A, 84B, 88, 89A, 89B) that detect electrical parameters in the neutral capacitors or in the connection path; and control devices (100, 90, 110, 130). When performing switching control of the inverter to pass a current through the connection path, the control devices determine whether or not an electrical interruption anomaly has occurred in the connection path on the basis of detection values of the parameter detection units.

Description

Cross - reference to related applications ,

[0001] This application is based on Japanese Patent Application No. 2023 - 092246 filed on June 5, 2023, the contents of which are incorporated herein by reference.

Technical Field

[0002] This disclosure relates to a power conversion device and a program.

Background Art

[0003] Conventionally, a power conversion device including a motor, an inverter, a storage battery, and a control device has been known. Such a power conversion device includes, for example, the technology described in Patent Document 1.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] A technology that can accurately determine that an abnormality has occurred in the above - mentioned power conversion device is desired.

[0006] The main object of this disclosure is to provide a power conversion device and a program that can accurately determine that an abnormality has occurred.

[0007] This disclosure relates to a power conversion device including an inverter having an upper - arm switch and a lower - arm switch, a motor having an armature winding electrically connected to a low - potential - side terminal of the upper - arm switch and a high - potential - side terminal of the lower - arm switch, in a power conversion device comprising: a high - potential - side path electrically connecting a positive - electrode terminal of a first power storage unit and a high - potential - side terminal of the upper - arm switch, A low-potential side path electrically connects the negative terminal of the second energy storage unit and the low-potential side terminal of the lower arm switch, A connection path that electrically connects the negative terminal of the first energy storage unit or the positive terminal of the second energy storage unit to the armature winding, A neutral point capacitor connected to the aforementioned connection path, A parameter detection unit for detecting electrical parameters in the neutral point capacitor or the connection path, Control device and Equipped with, When the control device is performing switching control of the inverter and supplying current to the connection path, it performs a determination process based on the detected value of the parameter detection unit to determine whether or not an electrical interruption abnormality has occurred in the connection path.

[0008] The power conversion device of this disclosure controls the switching of an inverter to supply current to the connection path. If an electrical interruption abnormality occurs in the connection path during the above switching control, the terminal voltage of the neutral point capacitor may become excessively high, causing the neutral point capacitor to fail.

[0009] Here, when current is flowing through the connection path, the neutral point capacitor or the electrical parameters in the connection path exhibit different behaviors depending on whether or not an electrical interruption abnormality has occurred in the connection path. The control device of this disclosure can accurately determine whether or not the above-mentioned electrical interruption abnormality has occurred based on the detection value of the parameter detection unit that detects the electrical parameters in the connection path when current is flowing through the connection path by switching control. [Brief explanation of the drawing]

[0010] The purposes and other objectives, features and benefits of this disclosure will be further clarified by the detailed description below, with reference to the attached drawings. Those drawings are: [Figure 1] Figure 1 is an overall diagram of the system according to the first embodiment. [Figure 2]FIG. 2 is a diagram showing the control state of the switch during high-voltage charging, [Figure 3] FIG. 3 is a diagram showing the control state of the switch during low-voltage charging, [Figure 4] FIG. 4 is a flowchart showing the procedure of the external charging control process, [Figure 5] FIG. 5 is a flowchart showing the procedure of the charging preparation process, [Figure 6] FIG. 6 is a flowchart showing the procedure of the charging stop process, [Figure 7] FIG. 7 is a flowchart showing the procedure of the fail-safe process, [Figure 8] FIG. 8 is a diagram showing the control state of the switch during equalization control according to the second embodiment, [Figure 9] FIG. 9 is a flowchart showing the procedure of the equalization control process, [Figure 10] FIG. 10 is a flowchart showing the procedure of the equalization preparation process, [Figure 11] FIG. 11 is a flowchart showing the procedure of the equalization stop process, [Figure 12] FIG. 12 is a flowchart showing the procedure of the fail-safe process, [Figure 13] FIG. 13 is a diagram showing the control state of the switch during high-voltage power supply according to the third embodiment, [Figure 14] FIG. 14 is a diagram showing the control state of the switch during low-voltage power supply, [Figure 15] FIG. 15 is a flowchart showing the procedure of the external charging control process according to the fourth embodiment, [Figure 16] FIG. 16 is an overall configuration diagram of the system according to a modification of the fourth embodiment, [Figure 17] FIG. 17 is an overall configuration diagram of the system according to the fifth embodiment, [Figure 18] FIG. 18 is an overall configuration diagram of the system according to the sixth embodiment, [Figure 19]FIG. 19 is an overall configuration diagram of a system according to a modification of the sixth embodiment, [Figure 20] FIG. 20 is an overall configuration diagram of a system according to the seventh embodiment, [Figure 21] FIG. 21 is a diagram showing the control state of switches during high-voltage charging, [Figure 22] FIG. 22 is a diagram showing the control state of switches during low-voltage charging, [Figure 23] FIG. 23 is a diagram showing the control state of switches during equalization control, [Figure 24] FIG. 24 is a diagram showing the control state of switches during high-voltage power supply, [Figure 25] FIG. 25 is a diagram showing the control state of switches during low-voltage power supply, [Figure 26] FIG. 26 is an overall configuration diagram of a system according to other embodiments, [Figure 27] FIG. 27 is an overall configuration diagram of a system according to other embodiments, <000,0110>FIG. 28 is an overall configuration diagram of a system according to other embodiments.

MODE FOR CARRYING OUT THE INVENTION

[0011] A plurality of embodiments will be described while referring to the drawings. In the plurality of embodiments, parts that are functionally and / or structurally corresponding and / or associated may be assigned the same reference numerals, or reference numerals that differ in the hundreds place or more. For corresponding parts and / or associated parts, the description of other embodiments can be referred to.

[0012] <First Embodiment> Hereinafter, a first embodiment in which a power conversion device according to the present disclosure is embodied will be described while referring 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 constitutes an in-vehicle system.

[0013] As shown in Figure 1, the power converter comprises a motor 10, an inverter 20, a high-potential path 22H, and a low-potential path 22L. The motor 10 is a three-phase synchronous machine and comprises star-connected armature windings 11 for U, V, and W phases, and a rotor (not shown). The armature windings 11 for 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 vehicle's drive wheels. Therefore, the motor 10 is the source of torque that drives the vehicle.

[0014] The inverter 20 is equipped with three series connections of 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 a freewheeling diode, is connected in antiparallel to the lower arm switch SWL. In this embodiment, each switch SWH and SWL is an IGBT.

[0015] The inverter 20 is equipped with a smoothing capacitor 21. A long high-potential path 22H is connected to the high-potential terminal of the smoothing capacitor 21. A long low-potential path 22L is connected to the low-potential terminal of the smoothing capacitor 21. The high-potential path 22H and the low-potential path 22L are, for example, electrical paths such as busbars. The smoothing capacitor 21 may be provided outside the inverter 20.

[0016] In each phase, the first end of the armature winding 11 is connected to the connection point between the emitter, which is the low-potential terminal of the upper arm switch SWH, and the collector, which is the high-potential terminal of the lower arm switch SWL, via a conductive member 23 such as a busbar. The second ends of the armature windings 11 of each phase are connected at the neutral point O. In this embodiment, the number of turns of the armature windings 11 of each phase is set to be the same. As a result, the inductance of the armature windings 11 of each phase is set to be the same, for example.

[0017] The collector of the upper arm switch SWH for each phase is connected to the high-potential path 22H. The emitter of the lower arm switch SWL for each phase is connected to the low-potential path 22L.

[0018] The system comprises a first battery 31 (corresponding to the "first energy storage unit") and a second battery 32 (corresponding to the "second energy storage unit"). Each battery 31 and 32 serves as a power source for rotating the rotor of the motor 10. Each battery 31 and 32 is a battery pack comprising a series connection of multiple unit batteries. A unit battery is either a single battery cell or a series connection of multiple battery cells. In this embodiment, the full charge capacity (specifically, for example, the rated full charge capacity) [Ah] of each unit battery constituting the first battery 31 and the second battery 32 is the same. The positive terminal of the first battery 31 is connected to a high-potential side path 22H via a first fuse 41, and the negative terminal of the second battery 32 is connected to a low-potential side path 22L via a second fuse 42. The terminal voltages (e.g., rated voltages) of each battery cell constituting the battery pack are set to be the same, for example. The battery cells are secondary batteries such as lithium-ion batteries. In this embodiment, the terminal voltage (e.g., rated voltage) of the first battery 31 is higher than the terminal voltage (e.g., rated voltage) of the second battery 32. This configuration can be achieved, for example, by increasing the number of unit batteries constituting the first battery 31 compared to the number of unit batteries constituting the second battery 32.

[0019] The power converter is equipped with a main switch for electrically connecting or disconnecting the first and second batteries 31 and 32 and the inverter 20. Specifically, the main switch consists of a high-potential side main switch SMRH, a low-potential side main switch SMRL, and a pre-charge main switch SMRP. In this embodiment, each of the main switches SMRH, SMRL, and SMRP is a mechanical relay. When each of the main switches SMRH, SMRL, and SMRP is turned off, it prevents the flow of current in both directions, and when it is turned on, it allows the flow of current in both directions. The high-potential side main switch SMRH is provided in the high-potential side path 22H, and the low-potential side main switch SMRL is provided in the low-potential side path 22L. A series connection of the pre-charge main switch SMRP and the pre-charge resistor 40 is connected in parallel to the low-potential side main switch SMRL. Note that each of the main switches SMRH, SMRL, and SMRP is not limited to a mechanical relay, but may be, for example, a semiconductor switching element.

[0020] Each of the batteries 31 and 32 can be charged from an external charger located outside the vehicle via external charging control. The external charger is, for example, a stationary charger.

[0021] Each of the batteries 31 and 32 can supply power to external power supply targets outside the vehicle via external power supply control. External power supply control when the power supply target is a grid power source is also called V2G (Vehicle to Grid). External power supply control when the power supply target is electrical equipment in a building such as a residence is also called V2H (Vehicle to Home).

[0022] The power converter includes a high-potential side connection switch DCRH and a low-potential side connection switch DCRL for electrically connecting or disconnecting the external charger or power supply unit and the first and second storage batteries 31 and 32. In this embodiment, each connection switch DCRH and DCRL is a mechanical relay. When each connection switch DCRH and DCRL is in the off state, it prevents the flow of current in both directions, and when it is in the on state, it allows the flow of current in both directions. The high-potential side connection switch DCRH is provided in the high-potential side path 22H in the portion closer to the inverter 20 than the high-potential side main switch SMRH. The low-potential side connection switch DCRL is provided in the low-potential side path 22L in the portion closer to the inverter 20 than the low-potential side main switch SMRL. Note that each connection switch DCRH and DCRL is not limited to a mechanical relay, but may also be, for example, a semiconductor switching element.

[0023] The power converter includes a battery-to-battery switch 50 (corresponding to a "power storage unit switch"), a bypass switch 60, a first motor-side switch 71, a second motor-side switch 72, and a connection path 73 for switching the connection state of the first battery 31 and the second battery 32. In this embodiment, the battery-to-battery switch 50, the bypass switch 60, and the motor-side switches 71 and 72 are mechanical relays. When the battery-to-battery switch 50, the bypass switch 60, and the motor-side switches 71 and 72 are turned off, they block the flow of current in both directions, and when they are turned on, they allow the flow of current in both directions. Note that the battery-to-battery switch 50, the bypass switch 60, and the motor-side switches 71 and 72 are not limited to mechanical relays, but may also be semiconductor switching elements, for example.

[0024] The battery-to-battery switch 50 connects the negative terminal of the first battery 31 and the positive terminal of the second battery 32. When the battery-to-battery switch 50 is turned ON, the negative terminal of the first battery 31 and the positive terminal of the second battery 32 are electrically connected. Conversely, when the battery-to-battery switch 50 is turned OFF, the negative terminal of the first battery 31 and the positive terminal of the second battery 32 are electrically disconnected.

[0025] The bypass switch 60 connects the negative terminal of the first battery 31 to the low-potential path 22L. When the bypass switch 60 is turned ON, the negative terminal of the first battery 31 and the negative terminal of the second battery 32 are electrically connected. Conversely, when the bypass switch 60 is turned OFF, the negative terminal of the first battery 31 and the negative terminal of the second battery 32 are electrically disconnected.

[0026] In this embodiment, the first battery 31 and the second battery 32 constitute the battery unit 30.

[0027] The connection path 73 is an electrical path that connects the positive terminal of the second battery 32 to the neutral point O. The connection path 73 is provided with the first motor-side switch 71 and the second motor-side switch 72, starting from the second battery 32.

[0028] The power converter includes a neutral point capacitor 74, which is a capacitor connecting the connection path 73 and the low-potential side path 22L. The first end of the neutral point capacitor 74 is connected to the portion of the connection path 73 between the first motor-side switch 71 and the second motor-side switch 72. The second end of the neutral point capacitor 74 is connected to the portion of the low-potential side path 22L that is closer to the inverter 20 than the low-potential side main switch SMRL and the pre-charge main switch SMRP.

[0029] When the first motor-side switch 71 is turned ON, the first terminal of the neutral point capacitor 74 is electrically connected to the positive terminal of the second battery 32. Conversely, when the first motor-side switch 71 is turned OFF, the first terminal of the neutral point capacitor 74 is electrically disconnected from the positive terminal of the second battery 32. When the second motor-side switch 72 is turned ON, the neutral point O of the armature winding 11 is electrically connected to the first terminal of the neutral point capacitor 74. Conversely, when the second motor-side switch 72 is turned OFF, the neutral point O and the first terminal of the neutral point capacitor 74 are electrically disconnected.

[0030] The power converter is equipped with a first current sensor 81, a second current sensor 82, a phase current sensor 83, and a motor current sensor 84 as current sensors to detect the current flowing through each part of itself. The first current sensor 81 detects the current flowing through the first battery 31, and the second current sensor 82 detects the current flowing through the second battery 32. The phase current sensor 83 detects the current flowing through the armature windings 11 of each phase. The motor current sensor 84 detects the current flowing through the part of the connection path 73 that is on the neutral point O side of the connection point with the neutral point capacitor 74.

[0031] The power converter includes a first voltage sensor 86 for detecting the terminal voltage of the first battery 31, a second voltage sensor 87 for detecting the terminal voltage of the second battery 32, a capacitor voltage sensor 85 (corresponding to the "parameter detection unit") for detecting the terminal voltage of the neutral point capacitor 74, and a power supply voltage sensor 102 for detecting the terminal voltage of the smoothing capacitor 21. In addition, the power converter includes a rotation angle sensor (not shown) for detecting the rotation angle (electrical angle) of the rotor.

[0032] The system includes a battery ECU 90 that controls the battery unit 30 and a motor ECU 100 that controls the inverter 20. The battery ECU 90 is an electronic control unit (ECCU) mainly composed of a microcontroller 91. The motor ECU 100 is an electronic control unit mainly composed of a microcontroller 101. The battery ECU 90 and the motor ECU 100 can exchange information via a communication unit such as CAN communication.

[0033] Each microcontroller 91,101 is equipped with a CPU (Central Processing Unit). The functions provided by each microcontroller 91,101 can be provided by software recorded in a physical memory device and the computer that executes it, by software only, by hardware only, or by a combination thereof. For example, if each microcontroller 91,101 is provided by electronic circuits which are hardware, it can be provided by digital circuits including a large number of logic circuits, or by analog circuits. For example, each microcontroller 91,101 executes a program stored in a non-transitory tangible storage medium which serves as its own memory. The program includes, for example, a program for processing as shown in Figures 4 to 7 described later. The method corresponding to the program is executed when a set of instructions constituting the program is executed. The memory is, for example, non-volatile memory. The program stored in the memory can be updated via a communication network such as the Internet, for example, OTA (Over The Air).

[0034] The battery ECU 90 receives the detection values ​​from the first current sensor 81, the second current sensor 82, the first voltage sensor 86, and the second voltage sensor 87. The motor ECU 100 receives the detection values ​​from the phase current sensor 83, the motor current sensor 84, the capacitor voltage sensor 85, the power supply voltage sensor 102, and the rotation angle sensor.

[0035] The motor ECU 100 controls the switching of switches SWH and SWL that make up the inverter 20 in order to feed back the control amount of the motor 10 to a command value based on the detected 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. As a result, the upper arm switch SWH and the lower arm switch SWL are alternately turned ON, and the rotational power of the rotor of the motor 10 is transmitted to the drive wheels, causing the vehicle to move.

[0036] Furthermore, if the motor ECU 100 determines that the voltage detected by the power supply voltage sensor 102 exceeds the judgment voltage, it determines that an overvoltage abnormality has occurred in the inverter 20 and performs an overvoltage stop process to stop the switching control of the inverter 20.

[0037] Each of the main switches SMRH, SMRL, SMRP, each of the connection switches DCRH, DCRL, the battery-to-battery switch 50, the bypass switch 60, and each of the motor-side switches 71, 72 may be controlled by either the battery ECU 90 or the motor ECU 100. In this embodiment, each of the main switches SMRH, SMRL, SMRP, the battery-to-battery switch 50, the bypass switch 60, and the first motor-side switch 71 are controlled by the battery ECU 90, and each of the connection switches DCRH, DCRL, and the second motor-side switch 72 are controlled by the motor ECU 100.

[0038] Next, we will explain external charging control.

[0039] In this embodiment, the external charger is either a high-voltage charger 200 or a low-voltage charger 210, as shown in Figures 2 and 3. The charging voltage of the high-voltage charger 200 is higher than the terminal voltage (specifically, the rated voltage) of the series connection of the first and second batteries 31 and 32, for example, 800V. The charging voltage of the low-voltage charger 210 is lower than the terminal voltage of the series connection of the first and second batteries 31 and 32, and higher than the terminal voltage (specifically, the rated voltage) of the first battery 32, for example, 400V. When the first and second batteries 31 and 32 are charged by the external charger, the high-potential side connection switch DCRH and the low-potential side connection switch DCRL are switched to the ON state. On the other hand, when charging by the external charger is not performed or the external charger is not connected to the power converter, the high-potential side connection switch DCRH and the low-potential side connection switch DCRL are switched to the OFF state.

[0040] Figure 2 shows the control state of each switch during external charging control using the high-voltage charger 200. When the motor ECU 100 determines that the external charger connected to the power converter is the high-voltage charger 200, it turns off the second motor-side switch 72 and the upper and lower arm switches SWH and SWL of all phases of the inverter 20. Also, when the battery ECU 90 determines that the external charger connected to the power converter is the high-voltage charger 200, it turns on the high-potential side main switch SMRH, the low-potential side main switch SMRL, and the inter-battery switch 50, and turns off the pre-charge main switch SMRP, the bypass switch 60, and the first motor-side switch 71. As a result, the first battery 31 and the second battery 32 are connected in series with respect to the high-voltage charger 200. Therefore, current flows through the closed circuit including the high-voltage charger 200, the high-potential path 22H, the first battery 31, the battery-to-battery switch 50, the second battery 32, and the low-potential path 22L, and the first battery 31 and the second battery 32 are charged in series. At this time, since the upper arm switch SWH and the second motor-side switch 72 of the inverter 20 are in the OFF state, the charging current from the high-voltage charger 200 can be prevented from flowing to the inverter 20 and the armature winding 11.

[0041] Figure 3 shows the control state of each switch during external charging control using the low-voltage charger 210. When the motor ECU 100 determines that the external charger connected to the power converter is the low-voltage charger 210, it turns on the second motor-side switch 72. When the battery ECU 90 determines that the external charger connected to the power converter is the low-voltage charger 210, it turns on the high-potential side main switch SMRH, the low-potential side main switch SMRL, the bypass switch 60, and the first motor-side switch 71, and turns off the pre-charge main switch SMRP and the inter-battery switch 50. As a result, current flows through the closed circuit including the low-voltage charger 210, the high-potential side path 22H, the first battery 31, the bypass switch 60, and the low-potential side path 22L, and the first battery 31 is charged.

[0042] In external charging control by the low-voltage charger 210, the motor ECU 100 reduces the output voltage of the low-voltage charger 210 and supplies it to the second battery 32 by switching control that alternately turns on at least one phase of the upper and lower arm switches SWH and SWL, or by switching control of at least one phase of the upper arm switch SWH while the lower arm switches SWL of all phases of the inverter 20 are turned off. Specifically, the motor ECU 100 performs the above switching control to control the voltage detected by the capacitor voltage sensor 85 (hereinafter referred to as the neutral point capacitor voltage VN) to the target charging voltage. As a result, current flows through the closed circuit including the low-voltage charger 210, the high-potential side path 22H, the upper arm switch SWH of the inverter 20, the armature winding 11, the neutral point O, the second motor side switch 72, the first motor side switch 71, the second battery 32, and the low-potential side path 22L, and the second battery 32 is charged. Since the terminal voltage of the second battery 32 is lower than the terminal voltage of the first battery 31, the target charging voltage of the second battery 32 is lower than the target charging voltage of the first battery 31.

[0043] Incidentally, during the execution of external charging control, an electrical interruption abnormality may occur in the portion of the connection path 73 that is on the second battery 32 side of the connection point with the neutral point capacitor 74. The interruption abnormality includes, for example, the following abnormalities (A) to (C).

[0044] (A) An abnormality in which the first motor-side switch 71 remains in the off state despite being controlled to be on, even when the first motor-side switch 71 is functioning normally. This abnormality occurs, for example, due to an abnormality in the signal path from the battery ECU 90 to the first motor-side switch 71.

[0045] (B) Open fault of the first motor side switch 71.

[0046] (C) Disconnection or failure of the wiring constituting connection path 73.

[0047] If the above-mentioned interruption abnormality occurs while external charging control is being executed, the terminal voltage of the neutral point capacitor 74 may become excessively high, potentially causing the neutral point capacitor 74 to fail. For example, if a short circuit occurs as a failure of the neutral point capacitor 74, an overcurrent may flow into the inverter 20 before the detection voltage of the power supply voltage sensor 102 exceeds the judgment voltage during the overvoltage stop process described above, potentially causing the inverter 20 to fail. Therefore, in this embodiment, a fail-safe process is performed to detect the interruption abnormality and suppress the occurrence of the above-mentioned problem.

[0048] Figure 4 shows the procedure for external charging control processing by the low-voltage charger 210, including fail-safe processing. This process is performed in cooperation with the motor ECU 100 and the battery ECU 90. In this embodiment, before the start of external charging control, each switch DCRH, DCRL, SMRH, SMRL, SMRP, 50, 60, 71, and 72 is assumed to be in the OFF state.

[0049] In step S10, the motor ECU 100 and the battery ECU 90 perform a charging preparation process. Figure 5 is a flowchart showing the procedure for the charging preparation process.

[0050] In step S20, the motor ECU 100 and the battery ECU 90 determine that the vehicle's start switch (e.g., ignition switch) has been turned on by the user. Then, in step S21, the motor ECU 100 starts monitoring the voltage change rate Va, which is the rate of change of the neutral point capacitor voltage VN. For each control cycle, the motor ECU 100 starts the process of calculating the voltage change rate Va based on the neutral point capacitor voltage VN. For example, the voltage change rate Va may be calculated by subtracting the neutral point capacitor voltage VN from the neutral point capacitor voltage VN of the previous control cycle from the neutral point capacitor voltage VN of the current control cycle and dividing the result by the length of one control cycle. Alternatively, for example, the neutral point capacitor voltage VN may be input to a differentiating circuit, and the output value of the differentiating circuit may be used as the voltage change rate Va.

[0051] In step S22, the battery ECU 90 controls the bypass switch 60 to turn on. In the following step S23, the battery ECU 90 controls the precharge main switch SMRP to turn on, and in the following step S24, it controls the high-potential side main switch SMRH to turn on. As a result, in step S25, the smoothing capacitor 21 is precharged by the first storage battery 31, and the terminal voltage of the smoothing capacitor 21 rises to a voltage equal to the terminal voltage of the first storage battery 31.

[0052] Once the pre-charge process is complete, the battery ECU 90 controls the low-potential side main switch SMRL to ON in step S26, and then controls the pre-charge main switch SMRP to OFF in the following step S27.

[0053] In step S28, the motor ECU 100 controls the second motor side switch 72 to be turned ON.

[0054] In step S29, the motor ECU 100 initiates switching control to alternately turn on at least one phase of the upper and lower arm switches SWH and SWL, or to initiate switching control of at least one phase of the upper arm switch SWH while all phases of the lower arm switch SWL are turned off, in order to precharge the neutral point capacitor 74. As a result, in step S30, the neutral point capacitor 74 is precharged by the first battery 31, and the terminal voltage of the neutral point capacitor 74 rises to a voltage equivalent to the terminal voltage of the second battery 32. During the precharging process of the neutral point capacitor 74, the motor ECU 100 may, for example, initiate switching control of the inverter 20 to control the neutral point capacitor voltage VN to the second detection voltage VL, which is the detection voltage of the second voltage sensor 87.

[0055] Once the pre-charge process is complete, the battery ECU 90 controls the first motor-side switch 71 to ON in step S31, the high-potential-side connection switch DCRH to ON in the following step S32, and the low-potential-side connection switch DCRL to ON in the following step S33. This completes the charging preparation process.

[0056] Returning to the explanation of Figure 4, in step S11, the motor ECU 100 performs a charging process by switching control of the inverter 20 to reduce the output voltage of the low-voltage charger 210 and supplying it to the second battery 32. At this time, the motor ECU 100 transmits a command output current to the low-voltage charger 210 based on the magnitude of the charging current flowing from the low-voltage charger 210 to the first battery 31 and the magnitude of the charging current flowing from the low-voltage charger 210 to the second battery 32 via the inverter 20 and connection path 73.

[0057] In step S12, the motor ECU 100 determines whether or not an instruction to stop the charging process has been issued.

[0058] If the motor ECU 100 determines that no stop instruction has been given in step S12, it proceeds to step S13 and determines whether the calculated voltage change rate Va exceeds the voltage threshold Vhth. If the motor ECU 100 determines that the voltage change rate Va is less than or equal to the voltage threshold Vhth, it determines that no interruption abnormality has occurred and proceeds to step S11 to continue the charging process. On the other hand, if the motor ECU 100 determines that the voltage change rate Va exceeds the voltage threshold Vhth, it determines that an interruption abnormality has occurred and performs the fail-safe processing in step S15, which will be described later.

[0059] If a tripping abnormality occurs while external charging control is in operation, the rate at which the voltage across the terminals of the neutral point capacitor 74 rises increases rapidly. Therefore, the rate at which the voltage across the terminals of the neutral point capacitor 74 rises allows for faster detection of a tripping abnormality than the voltage across the terminals of the neutral point capacitor 74.

[0060] If the motor ECU 100 determines in step S12 that a stop command has been issued, it proceeds to step S14 and performs the charging stop process. Figure 6 is a flowchart showing the procedure for the charging stop process.

[0061] In step S40, the motor ECU 100 controls the high-potential side connection switch DCRH to be turned off, and in the following step S41, it controls the low-potential side connection switch DCRL to be turned off.

[0062] In step S42, the battery ECU 90 controls the low-potential side main switch SMRL to turn off, in the following step S43, the bypass switch 60 to turn off, and in the following step S44, the high-potential side main switch SMRH to turn off.

[0063] In step S45, the motor ECU 100 stops the switching control of the inverter 20 for charging. In step S46, the battery ECU 90 controls the first motor side switch 71 to the OFF position.

[0064] In step S47, the motor ECU 100 discharges the neutral point capacitor 74 by controlling the switching of at least one phase of the lower arm switch SWL. This causes the terminal voltage of the neutral point capacitor 74 to drop to 0. Once the discharge process is complete, in step S47, the motor ECU 100 controls the second motor side switch 72 to turn off.

[0065] In step S49, the motor ECU 100 discharges the smoothing capacitor 21 by controlling the switching of the inverter 20. This causes the terminal voltage of the smoothing capacitor 21 to drop to 0. Once the discharge process is complete, the motor ECU 100 stops controlling the switching of the inverter 20 and, in step S50, notifies a higher-level control device (not shown) that the charging process has been completed.

[0066] In step S51, the motor ECU 100 finishes monitoring the voltage change rate Va, and in step S52, it determines that the start switch has been turned off.

[0067] Figure 7 is a flowchart showing the fail-safe procedure.

[0068] In step S60, the motor ECU 100 determines that a cutoff abnormality has occurred. In this embodiment, the cutoff abnormality is determined to be an abnormality in which the first motor-side switch 71 is in the OFF state. The ECU also stops the switching control of the inverter 20 during the charging process and instructs the low-voltage charger 210 to stop outputting the charging current from the low-voltage charger 210.

[0069] In step S61, the motor ECU 100 controls the high-potential side connection switch DCRH to be turned off, and in the following step S62, it controls the low-potential side connection switch DCRL to be turned off.

[0070] In step S63, the battery ECU 90 controls the low-potential side main switch SMRL to turn off, in the following step S64, the bypass switch 60 to turn off, and in the following step S65, the high-potential side main switch SMRH to turn off.

[0071] In step S66, the motor ECU 100 discharges the neutral point capacitor 74 by controlling the switching of at least one phase of the lower arm switch SWL, similar to the process in step S47. This causes the terminal voltage of the neutral point capacitor 74 to drop to 0. Once the discharge process is complete, in step S67, the motor ECU 100 controls the second motor side switch 72 to turn off.

[0072] In step S68, the motor ECU 100 discharges the smoothing capacitor 21 by controlling the switching of the inverter 20, similar to the process in step S49. This causes the terminal voltage of the smoothing capacitor 21 to drop to 0. Once the discharge process is complete, the motor ECU 100 stops controlling the switching of the inverter 20. In step S69, the motor ECU 100 notifies the higher-level control device that the charging process has ended due to an abnormality.

[0073] In step S70, the motor ECU 100 finishes monitoring the voltage change rate Va, and in step S71, it determines that the start switch has been turned off.

[0074] Prior to the discharge of the smoothing capacitor 21, the main switches SMRH and SMRL are turned off. This allows for the safe discharge of the smoothing capacitor 21 while electrically isolating the first and second batteries 31 and 32 from the inverter 20.

[0075] Prior to the discharge of the smoothing capacitor 21, the connection switches DCRH and DCRL are turned off. This allows for the safe discharge of the smoothing capacitor 21 while electrically disconnecting the inverter 20 and the low-voltage charger 210.

[0076] According to the embodiment described above, it is possible to accurately determine when a shutdown abnormality has occurred and to proceed to fail-safe processing.

[0077] <Modified form of the first embodiment> Even if an abnormality occurs in the interruption detection function, the switching control of the inverter 20 can be stopped by the overvoltage stop process described above.

[0078] In step S13 of Figure 4, the motor ECU 100 may use the neutral point capacitor voltage VN instead of the voltage change rate Va. Specifically, the motor ECU 100 should proceed to step S11 if it determines that the neutral point capacitor voltage VN is below the threshold, and proceed to step S15 if it determines that the neutral point capacitor voltage VN is greater than the threshold.

[0079] <Second Embodiment> The second embodiment will now be described below, focusing on the differences from the first embodiment with reference to the drawings. In this embodiment, the motor ECU 100 performs equalization control by switching control of the inverter 20, thereby transferring power from one of the first battery 31 and the second battery 32 to the other. Equalization control makes it possible to make the SOC of each unit battery constituting the first battery 31 and the SOC of each unit battery constituting the second battery 32 equal.

[0080] Figure 8 shows the control status of each switch during equalization control. During equalization control, the connection switches DCRH and DCRL are turned off.

[0081] The battery ECU 90 controls the high-potential main switch SMRH, the low-potential main switch SMRL, the inter-battery switch 50, and the first motor-side switch 71 to turn ON, and controls the pre-charge main switch SMRP and the bypass switch 60 to turn OFF. The motor ECU 100 controls the second motor-side switch 72 to turn ON, and controls the switching of at least one phase of the inverter 20 in order to transmit power from one of the first battery 31 and the second battery 32 to the other.

[0082] More specifically, the motor ECU 100 performs a first control by controlling the switching of at least one phase of the upper arm switch SWH, thereby supplying current from the first battery 31 to the second battery 32 via the inverter 20, armature winding 11, and connection path 73. Furthermore, the motor ECU 100 performs a second control by controlling the switching of at least one phase of the lower arm switch SWL, thereby supplying current to the first battery 31 via the second battery 32, connection path 73, armature winding 11, and inverter 20.

[0083] Incidentally, during the execution of the first control, an electrical interruption may occur in the portion of the connection path 73 that is closer to the second battery 32 than the connection point with the neutral capacitor 74. This interruption includes the abnormalities (A) to (C) described above.

[0084] On the other hand, during the execution of the second control, an electrical interruption abnormality may occur in the portion of the connection path 73 that is closer to the armature winding 11 than to the connection point with the neutral capacitor 74. This interruption abnormality includes the following abnormalities (D) to (F).

[0085] (D) An abnormality in which the second motor-side switch 72 remains in the off state despite being controlled to be on, even when the second motor-side switch 72 is functioning normally. This abnormality occurs, for example, due to an abnormality in the signal path from the battery ECU 90 to the second motor-side switch 72.

[0086] (E) Open fault of the switch 72 on the second motor side.

[0087] (F) Disconnection or failure of the wiring constituting the connection path 73.

[0088] If a cutoff abnormality occurs during the execution of equalization control, the terminal voltage of the neutral point capacitor 74 may become excessively high, potentially causing the neutral point capacitor 74 to fail. Therefore, in this embodiment, a fail-safe process is performed to detect the cutoff abnormality and suppress the occurrence of the above-mentioned problem.

[0089] Figure 9 shows the procedure for the equalization control process, including fail-safe processing. This process is performed by the cooperation of the motor ECU 100 and the battery ECU 90. In this embodiment, before the start of the equalization control, each switch DCRH, DCRL, SMRH, SMRL, SMRP, 50, 60, 71, and 72 is assumed to be in the OFF state.

[0090] In step S80, the motor ECU 100 and the battery ECU 90 perform equalization preparation processing. Figure 10 is a flowchart showing the procedure for equalization preparation processing.

[0091] In step S91, the motor ECU 100 starts the process of calculating the voltage change rate Va based on the neutral point capacitor voltage VN for each control cycle, similar to the process in step S21.

[0092] In step S92, the battery ECU 90 controls the battery-to-battery switch 50 to turn on. In the following step S93, the battery ECU 90 controls the pre-charge main switch SMRP to turn on, and in the following step S94, it controls the high-potential side main switch SMRH to turn on. As a result, in step S95, the smoothing capacitor 21 is pre-charged by the series connection of the first and second storage batteries 31 and 32, and the terminal voltage of the smoothing capacitor 21 rises to a voltage equal to the terminal voltage of the series connection of the first and second storage batteries 31 and 32.

[0093] Once the pre-charge process is complete, the battery ECU 90 controls the low-potential side main switch SMRL to ON in step S96, and then controls the pre-charge main switch SMRP to OFF in the following step S97.

[0094] In step S98, the motor ECU 100 controls the second motor side switch 72 to be turned ON.

[0095] In step S99, the motor ECU 100 initiates switching control to alternately turn on at least one phase of the upper and lower arm switches SWH and SWL, or to start switching control of at least one phase of the upper arm switch SWH while all phases of the lower arm switch SWL are turned off, in order to precharge the neutral point capacitor 74. As a result, in step S100, the neutral point capacitor 74 is precharged by the series connection of the first and second batteries 31 and 32, and the terminal voltage of the neutral point capacitor 74 rises to a voltage equivalent to the terminal voltage of the second battery 32. During the precharging process of the neutral point capacitor 74, the motor ECU 100 may, for example, perform switching control of the inverter 20 to control the neutral point capacitor voltage VN to the second detection voltage VL.

[0096] Once the pre-charge process is complete, the battery ECU 90 controls the first motor-side switch 71 to turn ON in step S101. This completes the equalization preparation process.

[0097] Returning to the explanation of Figure 9, in step S81, the motor ECU 100 performs either the first control or the second control.

[0098] In step S82, the motor ECU 100 determines whether or not a stop instruction for equalization control has been issued.

[0099] If the motor ECU 100 determines in step S82 that no stop instruction has been given, it proceeds to step S83 and determines whether the calculated voltage change rate Va exceeds the voltage threshold Vhth. If the motor ECU 100 determines that the voltage change rate Va is less than or equal to the voltage threshold Vhth, it determines that no interruption abnormality has occurred and proceeds to step S81 to continue equalization control. On the other hand, if the motor ECU 100 determines that the voltage change rate Va exceeds the voltage threshold Vhth, it determines that an interruption abnormality has occurred and performs the fail-safe processing in step S85, which will be described later.

[0100] If the motor ECU 100 determines in step S82 that a stop instruction has been issued, it proceeds to step S84 and performs the equalization stop process. Figure 11 is a flowchart showing the procedure for the equalization stop process.

[0101] In step S110, the battery ECU 90 controls the low-potential side main switch SMRL to turn off, in the following step S111, the battery inter-switch 50 to turn off, and in the following step S112, the high-potential side main switch SMRH to turn off.

[0102] In step S113, the motor ECU 100 stops the switching control of the inverter 20 for equalization control. In step S114, the battery ECU 90 controls the first motor side switch 71 to the OFF position.

[0103] In step S115, the motor ECU 100 discharges the neutral point capacitor 74 by controlling the switching of at least one phase of the lower arm switch SWL. This causes the terminal voltage of the neutral point capacitor 74 to drop to 0. Once the discharge process is complete, in step S116, the motor ECU 100 controls the second motor side switch 72 to turn off.

[0104] In step S117, the motor ECU 100 performs switching control of the inverter 20, thereby discharging the smoothing capacitor 21. This causes the terminal voltage of the smoothing capacitor 21 to drop to 0. Once the discharge process is complete, in step S118, the motor ECU 100 stops monitoring the voltage change rate Va and terminates the equalization stop process.

[0105] Figure 12 is a flowchart showing the fail-safe procedure.

[0106] In step S120, the motor ECU 100 determines that a cutoff abnormality has occurred. Specifically, when the motor ECU 100 is executing the first control, it determines that a cutoff abnormality has occurred in the part of the connection path 73 that is on the second battery 32 side of the connection point with the neutral capacitor 74. In this embodiment, the motor ECU 100 determines that the cutoff abnormality is an abnormality in which the first motor side switch 71 is in the OFF state.

[0107] On the other hand, when the motor ECU 100 is performing the second control, it determines that a tripping abnormality has occurred in the portion of the connection path 73 that is closer to the armature winding 11 than the connection point with the neutral capacitor 74. In this embodiment, the motor ECU 100 determines that a tripping abnormality has occurred in which the second motor side switch 72 is turned off.

[0108] In step S121, the battery ECU 90 controls the low-potential side main switch SMRL to turn off, in the following step S122, the battery inter-switch 50 to turn off, and in the following step S123, the high-potential side main switch SMRH to turn off.

[0109] In step S124, the motor ECU 100 stops the switching control of the inverter 20 for equalization control. In step S125, the battery ECU 90 controls the first motor side switch 71 to the OFF position.

[0110] In step S126, the motor ECU 100 discharges the neutral point capacitor 74 by controlling the switching of at least one phase of the lower arm switch SWL, similar to the process in step S115. This causes the terminal voltage of the neutral point capacitor 74 to drop to 0. Once the discharge process is complete, in step S127, the motor ECU 100 controls the second motor side switch 72 to turn off.

[0111] In step S128, the motor ECU 100 discharges the smoothing capacitor 21 by controlling the switching of the inverter 20, similar to the process in step S117. This causes the voltage across the terminals of the smoothing capacitor 21 to drop to 0. Once the discharge process is complete, in step S129, the motor ECU 100 stops monitoring the voltage change rate Va. This completes the fail-safe process.

[0112] According to the embodiment described above, it is possible to accurately determine when a shutdown abnormality occurs during the execution of equalization control and to proceed to fail-safe processing.

[0113] <Third Embodiment> The third embodiment will be described below, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, it is determined whether or not a power interruption abnormality occurred during the execution of external power supply control.

[0114] Figure 13 shows the control state of each switch during external power supply control, where power is supplied from the first and second batteries 31 and 32 to the high-voltage power supply target unit 220. When the motor ECU 100 determines that the power supply target unit connected to the power converter is the high-voltage power supply target unit 220, it turns off the second motor-side switch 72 and the upper and lower arm switches SWH and SWL of all phases of the inverter 20, and turns on the connection switches DCRH and DCRL. When the battery ECU 90 determines that the power supply target unit connected to the power converter is the high-voltage power supply target unit 220, it turns on the high-potential side main switch SMRH, the low-potential side main switch SMRL and the battery-to-battery switch 50, and turns off the pre-charge main switch SMRP, the bypass switch 60 and the first motor-side switch 71. As a result, the first battery 31 and the second battery 32 are connected in series to the high-voltage power supply target unit 220. Therefore, current flows through the closed circuit including the first battery 31, the high-potential path 22H, the high-voltage power supply target unit 220, the low-potential path 22L, and the second battery 32, and power is supplied from the first battery 31 and the second battery 32 to the high-voltage power supply target unit 220.

[0115] Figure 14 shows the control state of each switch during external power supply control, where power is supplied from the first and second batteries 31 and 32 to the low-voltage power supply target unit 230. The rated voltage of the low-voltage power supply target unit 230 is lower than the rated voltage of the high-voltage power supply target unit 220. When the motor ECU 100 determines that the power supply target unit connected to the power converter is the low-voltage power supply target unit 230, it turns on the second motor-side switch 72 and the respective connection switches DCRH and DCRL. When the battery ECU 90 determines that the power supply target unit connected to the power converter is the low-voltage power supply target unit 230, it turns on the high-potential side main switch SMRH, the low-potential side main switch SMRL, the bypass switch 60 and the first motor-side switch 71, and turns off the pre-charge main switch SMRP and the battery-to-battery switch 50. As a result, current flows through the closed circuit including the first battery 31, the high-potential path 22H, the low-voltage power supply target unit 230, the low-potential path 22L, and the bypass switch 60, and power is supplied from the first battery 31 to the low-voltage power supply target unit 230.

[0116] In controlling the external power supply to the low-voltage power supply target unit 230, the motor ECU 100 increases the output voltage of the second battery 32 and supplies it to the low-voltage power supply target unit 230 by performing switching control to alternately turn on at least one phase of the upper and lower arm switches SWH and SWL, or by performing switching control of at least one phase of the lower arm switch SWL while the upper arm switch SWH of all phases of the inverter 20 is turned off. Specifically, the motor ECU 100 performs the above switching control to control the terminal voltage of the smoothing capacitor 21 detected by the power supply voltage sensor 102 to the target power supply voltage. As a result, current flows through the closed circuit including the second battery 32, connection path 73, armature winding 11, inverter 20, high-potential side path 22H, low-voltage power supply target unit 230, and low-potential side path 22L, and power is supplied from the second battery 32 to the low-voltage power supply target unit 230.

[0117] Incidentally, during the execution of external power supply control, an electrical interruption may occur in the portion of the connection path 73 that is closer to the armature winding 11 than the connection point with the neutral capacitor 74. This interruption includes the abnormalities (D) to (F) described above.

[0118] If a cutoff abnormality occurs during the execution of external power supply control, the terminal voltage of the neutral point capacitor 74 may become excessively high, potentially causing the neutral point capacitor 74 to fail. Therefore, in this embodiment, as in the first embodiment, a fail-safe process is performed to detect the cutoff abnormality and suppress the occurrence of the above-mentioned problem. The external power supply control process, including the fail-safe process, is the same as the process shown in Figure 4 above. If the motor ECU 100 determines that the voltage change rate Va exceeds the voltage threshold Vhth during the execution of external power supply control, it performs the fail-safe process as in step S15.

[0119] According to the embodiment described above, it is possible to accurately determine when a power interruption abnormality occurs during the execution of external power supply control and to transition to fail-safe processing.

[0120] <Fourth Embodiment> The fourth embodiment will be described below, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, it is determined whether or not a tripping abnormality has occurred based on the detected current IN of the motor current sensor 84.

[0121] Figure 15 is a flowchart showing the procedure for external charging control processing, including fail-safe processing. In this embodiment, in step S21 of step S10 shown in Figure 10, the motor ECU 100 starts a process to acquire the detected current IN of the motor current sensor 84 at each control cycle, instead of monitoring the voltage change rate Va.

[0122] In step S16, the motor ECU 100 determines whether the detected current IN is less than the current threshold Ith. The process in step S16 is to determine whether a cutoff abnormality has occurred. The current threshold Ith is a value used to determine whether no current is flowing through the connection path 73, and is set to a value slightly greater than 0, for example. If the motor ECU 100 determines that the detected current IN is greater than or equal to the current threshold Ith, it determines that no cutoff abnormality has occurred and proceeds to step S11 to continue the charging process. On the other hand, if the motor ECU 100 determines that the detected current IN is less than the current threshold Ith, it determines that a cutoff abnormality has occurred and performs the fail-safe process in step S15.

[0123] The embodiment described above also makes it possible to determine whether or not a circuit breaker malfunction has occurred.

[0124] <Modified form of the fourth embodiment> The process for determining an interruption abnormality based on the detected current IN can also be applied during equalization control in the second embodiment. In this case, in step S120 of Figure 12, the motor ECU 100 determines that an interruption abnormality has occurred in the connection path 73, and specifically, it determines that an abnormality has occurred in which the first motor-side switch 71 or the second motor-side switch 72 is in the OFF state.

[0125] Furthermore, the process for determining an interruption abnormality based on the detected current IN can also be applied to external power supply control in the third embodiment. In this case, the motor ECU 100 determines that an interruption abnormality has occurred in the connection path 73, and specifically, it determines that an abnormality has occurred in which the first motor-side switch 71 or the second motor-side switch 72 is in the OFF state.

[0126] The installation location of the motor current sensor 84 is not limited to the location shown in Figure 1. For example, as shown in Figure 16, the motor current sensor 84A may be installed in the part of the connection path 73 between the connection point with the neutral capacitor 74 and the first motor-side switch 71, or the motor current sensor 84B may be installed in the part of the connection path 73 closer to the second battery 32 than the first motor-side switch 71.

[0127] <Fifth Embodiment> The fifth embodiment will be described below, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the voltage difference across the first motor-side switch 71 is used as a parameter to determine whether or not a tripping abnormality has occurred.

[0128] As shown in Figure 17, the power converter includes a differential voltage detection unit 88 that detects the voltage difference across the first motor-side switch 71. The differential voltage ΔV detected by the differential voltage detection unit 88 is input to the motor ECU 100. The motor ECU 100 acquires the detected differential voltage ΔV for each control cycle.

[0129] In step S13 of Figure 4, the motor ECU 100 determines whether the acquired differential voltage ΔV is greater than the threshold Δth. The threshold Δth is a value used to determine whether current is flowing through the connection path 73. If the motor ECU 100 determines that the differential voltage ΔV is less than or equal to the threshold Δth, it determines that no interruption abnormality has occurred and proceeds to step S11 to continue the charging process. On the other hand, if the motor ECU 100 determines that the differential voltage ΔV is greater than the threshold Δth, it determines that an interruption abnormality has occurred and performs the fail-safe process in step S15.

[0130] <Modified form of the fifth embodiment> The process for determining interruption abnormalities based on differential voltage ΔV can also be applied during equalization control in the second embodiment and during external power supply control in the third embodiment.

[0131] <Sixth Embodiment> The sixth embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the power transmitted through the connection path 73 is used as a parameter to determine whether or not a circuit breaker abnormality has occurred.

[0132] As shown in Figure 18, the power converter includes a power detection unit 89A that detects the power transmitted through the connection path 73. The power WN detected by the power detection unit 89A is input to the motor ECU 100. The motor ECU 100 acquires the detected power WN at each control cycle.

[0133] In step S13 of Figure 4, the motor ECU 100 determines whether the acquired power WN is less than the power threshold Wth. The power threshold Wth is a value used to determine whether power is being transmitted to the connection path 73, and is set to a value slightly greater than 0, for example. If the motor ECU 100 determines that the power WN is equal to or greater than the power threshold Wth, it determines that no interruption error has occurred and proceeds to step S11 to continue the charging process. On the other hand, if the motor ECU 100 determines that the power WN is less than the power threshold Wth, it determines that an interruption error has occurred and performs the fail-safe process in step S15.

[0134] <Modified form of the sixth embodiment> The differential power across the first motor-side switch 71 may be used as a parameter to determine whether or not a tripping abnormality has occurred. As shown in Figure 19, the power converter includes a differential power detection unit 89B that detects the differential power across the first motor-side switch 71. The differential power ΔW detected by the differential power detection unit 89B is input to the motor ECU 100. The motor ECU 100 acquires the detected differential power ΔW for each control cycle.

[0135] In step S13 of Figure 4, the motor ECU 100 determines whether the acquired differential power ΔW is less than the threshold Δwth. If the motor ECU 100 determines that the differential power ΔW is greater than or equal to the threshold Δwth, it determines that no interruption has occurred and proceeds to step S11 to continue the charging process. On the other hand, if the motor ECU 100 determines that the differential power ΔW is less than the threshold Δwth, it determines that an interruption has occurred and performs the fail-safe process in step S15.

[0136] The process for determining interruption abnormalities based on power WN and differential power ΔW can also be applied during equalization control in the second embodiment and during external power supply control in the third embodiment.

[0137] <Seventh Embodiment> The seventh embodiment will now be described, focusing on the differences from the first to third embodiments, with reference to the drawings. In this embodiment, as shown in Figure 20, the connection path 73 electrically connects the neutral point O of the armature winding 11 to the negative terminal of the first battery 31. The bypass switch 61 connects the positive terminal of the second battery 32 to the high-potential side path 22H. The first end of the neutral point capacitor 75 is connected to the portion of the connection path 73 between the first motor-side switch 71 and the second motor-side switch 72. The second end of the neutral point capacitor 75 is connected to the portion of the high-potential side path 22H that is closer to the inverter 20 than the high-potential side main switch SMRH.

[0138] In this embodiment, the terminal voltage of the first battery 31 (e.g., rated voltage) is lower than the terminal voltage of the second battery 32 (e.g., rated voltage).

[0139] Next, the external charging control, equalization control, and external power supply control of this embodiment will be described.

[0140] First, let's explain external charging control. Figure 21 shows the control state of each switch during external charging control using the high-voltage charger 200. When the motor ECU 100 determines that the external charger connected to the power converter is the high-voltage charger 200, it turns off the second motor-side switch 72 and the upper and lower arm switches SWH and SWL of all phases of the inverter 20. Also, when the battery ECU 90 determines that the external charger connected to the power converter is the high-voltage charger 200, it turns on the high-potential side main switch SMRH, the low-potential side main switch SMRL, and the inter-battery switch 50, and turns off the pre-charge main switch SMRP, the bypass switch 61, and the first motor-side switch 71. As a result, the first battery 31 and the second battery 32 are charged in series with the high-voltage charger 200.

[0141] Figure 22 shows the control state of each switch during external charging control using the low-voltage charger 210. When the motor ECU 100 determines that the external charger connected to the power converter is the low-voltage charger 210, it turns on the second motor-side switch 72. When the battery ECU 90 determines that the external charger connected to the power converter is the low-voltage charger 210, it turns on the high-potential side main switch SMRH, the low-potential side main switch SMRL, the bypass switch 61, and the first motor-side switch 71, and turns off the pre-charge main switch SMRP and the inter-battery switch 50. As a result, the second storage battery 32 is charged.

[0142] In external charging control by the low-voltage charger 210, the motor ECU 100 reduces the output voltage of the low-voltage charger 210 and supplies it to the first battery 31 by switching control that alternately turns on at least one phase of upper and lower arm switches SWH and SWL, or by switching control of at least one phase of lower arm switch SWL while the upper arm switch SWH of all phases of the inverter 20 is turned off. Specifically, the motor ECU 100 performs the above switching control to control the neutral point capacitor voltage VN to the target charging voltage. As a result, the first battery 31 is charged. Since the terminal voltage of the first battery 31 is lower than the terminal voltage of the second battery 32, the target charging voltage of the first battery 31 is lower than the target charging voltage of the second battery 32.

[0143] During the execution of external charging control, an electrical interruption abnormality may occur in the portion of the connection path 73 that is closer to the first battery 31 than the connection point with the neutral point capacitor 74. Even in this case, it is possible to determine whether or not an interruption abnormality has occurred during the execution of external charging control, similar to the first embodiment.

[0144] Next, we will explain equalization control. Figure 23 shows the control state of each switch during equalization control. Note that during equalization control, the connection switches DCRH and DCRL are turned off.

[0145] The battery ECU 90 controls the high-potential side main switch SMRH, the low-potential side main switch SMRL, the inter-battery switch 50, and the first motor side switch 71 to turn ON, and controls the pre-charge main switch SMRP and the bypass switch 61 to turn OFF. The motor ECU 100 controls the second motor side switch 72 to turn ON and controls the switching of at least one phase of the inverter 20 in order to transmit power from one of the first battery 31 and the second battery 32 to the other.

[0146] During the execution of the first control, an electrical interruption abnormality may occur in the portion of the connection path 73 that is closer to the first battery 31 than the connection point with the neutral point capacitor 74. On the other hand, during the execution of the second control, an electrical interruption abnormality may occur in the portion of the connection path 73 that is closer to the armature winding 11 than the connection point with the neutral point capacitor 74. Even in such cases, during the execution of the equalization control, it is possible to determine whether or not an interruption abnormality has occurred, similar to the second embodiment.

[0147] Next, external power supply control will be explained. Figure 24 shows the control state of each switch during external power supply control, when power is supplied from the first and second batteries 31 and 32 to the high-voltage power supply target unit 220. When the motor ECU 100 determines that the power supply target unit connected to the power converter is the high-voltage power supply target unit 220, it turns off the second motor-side switch 72 and the upper and lower arm switches SWH and SWL of all phases of the inverter 20, and turns on the respective connection switches DCRH and DCRL. When the battery ECU 90 determines that the power supply target unit connected to the power converter is the high-voltage power supply target unit 220, it turns on the high-potential side main switch SMRH, the low-potential side main switch SMRL and the inter-battery switch 50, and turns off the pre-charge main switch SMRP, the bypass switch 61 and the first motor-side switch 71. As a result, power is supplied from the first battery 31 and the second battery 32 to the high-voltage power supply target unit 220.

[0148] Figure 25 shows the control state of each switch during external power supply control, where power is supplied from the first and second batteries 31 and 32 to the low-voltage power supply target unit 230. When the motor ECU 100 determines that the power supply target unit connected to the power converter is the low-voltage power supply target unit 230, it turns off the second motor-side switch 72 and turns on the connection switches DCRH and DCRL. When the battery ECU 90 determines that the power supply target unit connected to the power converter is the low-voltage power supply target unit 230, it turns on the high-potential side main switch SMRH, the low-potential side main switch SMRL, the bypass switch 61 and the first motor-side switch 71, and turns off the pre-charge main switch SMRP and the battery-to-battery switch 50. As a result, power is supplied from the second battery 32 to the low-voltage power supply target unit 230.

[0149] In controlling the external power supply to the low-voltage power supply target unit 230, the motor ECU 100 increases the output voltage of the first battery 31 and supplies it to the low-voltage power supply target unit 230 by performing switching control to alternately turn on at least one phase of the upper and lower arm switches SWH and SWL, or by performing switching control of at least one phase of the upper arm switch SWH while the lower arm switches SWL of all phases of the inverter 20 are turned off. Specifically, the motor ECU 100 performs the above switching control to control the terminal voltage of the smoothing capacitor 21 detected by the power supply voltage sensor 102 to the target power supply voltage. As a result, power is supplied from the first battery 31 to the low-voltage power supply target unit 230.

[0150] During the execution of external power supply control to the low-voltage power supply target unit 230, it is possible to determine whether or not a tripping abnormality has occurred, similar to the third embodiment.

[0151] <Other Embodiments> Furthermore, each of the above embodiments may be implemented with the following modifications.

[0152] The configuration of the seventh embodiment can be modified to apply the tripping abnormality determination process based on the detected current IN, differential voltage ΔV, power WN, and differential power ΔW described in the fourth to sixth embodiments.

[0153] Instead of the battery ECU 90, the motor ECU 100 may control the high-potential main switch SMRH, the low-potential main switch SMRL, the pre-charge main switch SMRP, and the first motor-side switch 71.

[0154] Furthermore, as shown in Figure 26, the system may also include a relay control device 110 that controls each of the main switches SMRH, SMRL, SMRP and each of the connection switches DCRH, DCRL, and a higher-level control device 120. The higher-level control device 120 is an electronic control device that is higher in level than the battery ECU 90, motor ECU 100, and relay control device 110. The relay control device 110 has a microcontroller 111, and the higher-level control device 120 has a microcontroller 121. Each control device 90, 100, 110, and 120 can exchange information with each other via a communication unit such as CAN communication.

[0155] Furthermore, as shown in Figure 27, the system may also include a single control device 130. The control device 130 is an electronic control device that has a microcontroller 131 and integrates the functions of the battery ECU 90 and the motor ECU 100.

[0156] In each of the above embodiments, either the first or second motor-side switch 71 or 72 may not be provided in the power converter. Also, both the first and second motor-side switches 71 or 72 may not be provided in the power converter.

[0157] As shown in Figure 28, the power conversion device may further include a neutral point capacitor 174 connecting the portion of the connection path 73 closer to the neutral point O than the first motor-side switch 71 to the high-potential-side path 22H, and a capacitor voltage sensor 185 for detecting the voltage across the terminals of the neutral point capacitor 174. In this case, for example, the neutral point capacitor 174 can be used as a smoothing capacitor during equalization control. Similarly, the power conversion device shown in Figure 20 may further include a neutral point capacitor connecting the portion of the connection path 73 closer to the neutral point O than the first motor-side switch 71 to the low-potential-side path 22L, and a capacitor voltage sensor for detecting the voltage across the terminals of the neutral point capacitor.

[0158] The switch for inverter 20 is not limited to IGBTs; for example, an N-channel MOSFET equipped with a body diode may also be used. In this case, the high-potential terminal of the N-channel MOSFET becomes the drain, and the low-potential terminal becomes the source.

[0159] • A high-potential side main switch SMRH does not necessarily need to be provided.

[0160] Instead of the low-potential main switch SMRL, the high-potential main switch SMRH may be connected in parallel to the pre-charge main switch SMRP and the pre-charge resistor 40 in series. In this case, the low-potential main switch SMRL may not be provided.

[0161] Fuses 41 and 42 do not necessarily need to be provided.

[0162] The motor is not limited to a star-connected configuration; it may also be delta-connected. Furthermore, the motor and inverter are not limited to three-phase; they may be two-phase or four-phase or more. Also, the motor is not limited to a permanent magnet synchronous machine with permanent magnets as field poles in the rotor; it may also be a wound-field synchronous machine with field windings as field poles in the rotor. In this case, the rotor may be equipped with both field windings and permanent magnets. Finally, the motor is not limited to a synchronous machine; it may also be an induction machine.

[0163] The energy storage unit to be charged by the external charger is not limited to a battery; for example, it may include a large-capacity electric double-layer capacitor, or both a battery and an electric double-layer capacitor.

[0164] The mobile body on which the power converter is mounted is not limited to a vehicle; for example, it could be an aircraft or a ship. Furthermore, the mounting location of the power converter is not limited to a mobile body; it could be a stationary device.

[0165] The control devices and methods described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control devices and methods described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control devices and methods described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium.

[0166] The following describes the characteristic configurations extracted from each of the embodiments described above. [Configuration 1] An inverter (20) having an upper arm switch (SWH) and a lower arm switch (SWL), A motor (10) having an armature winding (11) electrically connected to the low-potential terminal of the upper arm switch and the high-potential terminal of the lower arm switch, In a power converter equipped with, A high-potential side path (22H) electrically connects the positive terminal of the first energy storage unit (31) and the high-potential side terminal of the upper arm switch, A low-potential side path (22L) electrically connects the negative terminal of the second energy storage unit (32) and the low-potential side terminal of the lower arm switch, A connection path (73) electrically connects the negative terminal of the first energy storage unit or the positive terminal of the second energy storage unit to the armature winding, The neutral point capacitors (74, 75) connected to the aforementioned connection path, A parameter detection unit (85, 84, 84A, 84B, 88, 89A, 89B) for detecting electrical parameters in the neutral point capacitor or the connection path, Control devices (100, 90, 110, 130), Equipped with, The control device is a power converter that, when it is performing switching control of the inverter and supplying current to the connection path, performs a determination process to determine whether or not an electrical interruption abnormality has occurred in the connection path based on the detected value of the parameter detection unit. [Configuration 2] A switch (50) between energy storage units electrically connects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned ON, and electrically disconnects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned OFF, A bypass switch (60) electrically connects the negative terminal of the first energy storage unit and the negative terminal of the second energy storage unit when turned ON, and electrically disconnects the negative terminal of the first energy storage unit and the negative terminal of the second energy storage unit when turned OFF, Equipped with, The aforementioned connection path electrically connects the armature winding and the positive terminal of the second energy storage unit. The power conversion device according to configuration 1, wherein the neutral point capacitor (74) electrically connects the connection path and the low-potential side path. [Configuration 3] The control device is When an external charger (210) is electrically connected to the high-potential side path and the low-potential side path, with the inter-energy storage unit switch turned OFF and the bypass switch turned ON, the upper arm switch is switched to perform an external charging control that charges the second energy storage unit by flowing current through a closed circuit including the external charger, the inverter, the armature winding, the connection path and the second energy storage unit. The power conversion device according to configuration 2, wherein, as the determination process, during the execution of the external charging control, a process is performed to determine whether or not an electrical interruption abnormality has occurred in the portion of the connection path that is on the side of the second energy storage unit side of the connection point with the neutral point capacitor. [Structure 4] The motor-side switch (71) is provided in the portion of the connection path that is closer to the second energy storage unit than the connection point with the neutral point capacitor. The control device controls the motor-side switch to be turned ON in the external charging control, The power conversion device according to configuration 3, wherein the interruption abnormality is an abnormality in which the motor-side switch is turned off. [Composition 5] The control device is With the inter-energy storage unit switch turned ON and the bypass switch turned OFF, the first control involves supplying current from the first energy storage unit to the second energy storage unit via the inverter, the armature winding, and the connection path by performing switching control of the upper arm switch. With the inter-energy storage unit switch turned ON and the bypass switch turned OFF, a second control is performed to supply current from the second energy storage unit to the first energy storage unit via the connection path, the armature winding, and the inverter by performing switching control of the lower arm switch. Perform As the aforementioned determination process, During the execution of the first control, a process is performed to determine whether or not an electrical interruption abnormality has occurred in the portion of the connection path that is on the side of the second energy storage unit than the connection point with the neutral point capacitor. During the execution of the second control, a process is performed to determine whether or not an electrical interruption abnormality has occurred in the portion of the connection path that is on the armature winding side of the connection point with the neutral point capacitor, A power conversion device as described in configuration 2, which performs the following actions. [Composition 6] Of the aforementioned connection path, the first motor-side switch (71) is provided in the portion on the side of the second energy storage unit that is closer to the connection point with the neutral point capacitor, A second motor-side switch (72) is provided in the part of the aforementioned connection path that is closer to the armature winding than the connection point with the neutral point capacitor, Equipped with, The control device, in the first control and the second control, controls the first motor-side switch and the second motor-side switch to be ON. The interruption abnormality during the execution of the first control is an abnormality in which the first motor-side switch is turned off. The power converter according to configuration 5, wherein the interruption abnormality during the execution of the second control is an abnormality in which the second motor-side switch is turned off. [Composition 7] The control device is When the external power supply target unit (230) is electrically connected to the high-potential side path and the low-potential side path, the external power supply control is performed by switching the lower arm switch while the inter-energy storage unit switch is turned off and the bypass switch is turned on, thereby supplying current from the second energy storage unit to the external power supply target unit via the connection path, the armature winding, and the inverter. The power converter according to configuration 2, wherein the determination process involves determining whether an electrical interruption abnormality has occurred in the portion of the connection path that is on the armature winding side of the connection point with the neutral point capacitor while the external power supply control is being executed. [Structure 8] The motor-side switch (72) is provided in the portion of the connection path that is closer to the armature winding than the connection point with the neutral point capacitor. The control device controls the motor-side switch to be turned ON in the external power supply control, The power conversion device according to configuration 7, wherein the interruption abnormality is an abnormality in which the motor-side switch is turned off. [Composition 9] A switch (50) between energy storage units electrically connects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned ON, and electrically disconnects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned OFF, A bypass switch (61) electrically connects the positive terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned ON, and electrically disconnects the positive terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned OFF, Equipped with, The aforementioned connection path electrically connects the armature winding and the negative terminal of the first energy storage unit. The power conversion device according to configuration 1, wherein the neutral point capacitor (75) electrically connects the connection path and the high-potential side path. [Configuration 10] The control device is When an external charger (210) is electrically connected to the high-potential side path and the low-potential side path, the inter-energy storage unit switch is turned OFF and the bypass switch is turned ON, and the lower arm switch is switched to perform an external charging control that charges the first energy storage unit by flowing current through a closed circuit including the external charger, the first energy storage unit, the connection path, the armature winding and the inverter. The power conversion device according to configuration 9, wherein, as the determination process, during the execution of the external charging control, a determination is made as to whether or not an electrical interruption abnormality has occurred in the part of the connection path that is on the side of the first energy storage unit side of the connection point with the neutral point capacitor. [Composition 11] The motor-side switch (71) is provided in the portion of the connection path that is closer to the first energy storage unit than the connection point with the neutral point capacitor. The control device controls the motor-side switch to be turned ON in the external charging control, The power conversion device according to configuration 10, wherein the interruption abnormality is an abnormality in which the motor-side switch is turned off. [Composition 12] The control device is With the inter-energy storage unit switch turned ON and the bypass switch turned OFF, the first control involves supplying current from the first energy storage unit to the second energy storage unit via the inverter, the armature winding, and the connection path by performing switching control of the upper arm switch. With the inter-energy storage unit switch turned ON and the bypass switch turned OFF, a second control is performed to supply current from the second energy storage unit to the first energy storage unit via the connection path, the armature winding, and the inverter by performing switching control of the lower arm switch. Perform As the aforementioned determination process, During the execution of the first control, a process is performed to determine whether or not an electrical interruption abnormality has occurred in the part of the connection path that is on the side of the first energy storage unit side of the connection point with the neutral point capacitor, During the execution of the second control, a process is performed to determine whether or not an electrical interruption abnormality has occurred in the portion of the connection path that is on the armature winding side of the connection point with the neutral point capacitor, A power conversion device as described in configuration 9, which performs the following actions. [Composition 13] Of the aforementioned connection path, the first motor-side switch (71) is provided in the portion closer to the first energy storage unit than the connection point with the neutral point capacitor, A second motor-side switch (72) is provided in the part of the aforementioned connection path that is closer to the armature winding than the connection point with the neutral point capacitor, Equipped with, The control device turns on the first motor-side switch and the second motor-side switch in the first control and the second control. The interruption abnormality during the execution of the first control is an abnormality in which the first motor-side switch is turned off. The power converter according to configuration 12, wherein the interruption abnormality during the execution of the second control is an abnormality in which the second motor-side switch is turned off. [Composition 14] The control device is When the external power supply target unit (230) is electrically connected to the high-potential side path and the low-potential side path, the external power supply control is performed by controlling the switching of the lower arm switch while the inter-energy storage unit switch is turned off and the bypass switch is turned on, thereby supplying current to the external power supply target unit via current to the closed circuit including the external power supply target unit, the first energy storage unit, the connection path, the armature winding and the inverter. The power converter according to configuration 9, wherein the determination process involves determining whether an electrical interruption abnormality has occurred in the portion of the connection path that is on the armature winding side of the connection point with the neutral point capacitor while the external power supply control is being executed. [Composition 15] The motor-side switch (72) is provided in the portion of the connection path that is closer to the armature winding than the connection point with the neutral point capacitor. The control device controls the motor-side switch to be turned ON in the external power supply control, The power conversion device according to configuration 14, wherein the interruption abnormality is an abnormality in which the motor-side switch is turned off. [Composition 16] The parameter detection unit (85) detects the terminal voltage of the neutral point capacitor, The power converter according to any one of configurations 1 to 15, wherein the control device performs a determination process that calculates the rate of change (Va) of the detected terminal voltage, and determines that a cutoff abnormality has occurred when the calculated rate of change exceeds a threshold (Vhth). [Composition 17] The parameter detection units (84, 84A, 84B) detect the current flowing through the connection path, The power converter according to any one of configurations 1 to 15, wherein the control device performs a determination process to determine whether or not the interruption abnormality has occurred based on the detected current (IN). [Composition 18] The power conversion device according to any one of configurations 1 to 17, wherein the control device stops the switching control of the inverter when it determines that the interruption abnormality has occurred. [Composition 19] A smoothing capacitor (21) connected in parallel to the series connection of the upper arm switch and the lower arm switch, Main switches (SMRH, SMRL) provided in at least one of the high-potential path and the low-potential path, Equipped with, The power conversion device according to any one of configurations 1 to 18, wherein the control device, when it determines that the interruption abnormality has occurred, controls the main switch to the OFF position, then controls the switching of the inverter to discharge the smoothing capacitor, and stops the switching control of the inverter after the discharge is completed.

[0167] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure.

Claims

1. An inverter (20) having an upper arm switch (SWH) and a lower arm switch (SWL), A motor (10) having an armature winding (11) electrically connected to the low-potential terminal of the upper arm switch and the high-potential terminal of the lower arm switch, In a power conversion device equipped with, A high-potential side path (22H) electrically connects the positive terminal of the first energy storage unit (31) and the high-potential side terminal of the upper arm switch, A low-potential side path (22L) electrically connects the negative terminal of the second energy storage unit (32) and the low-potential side terminal of the lower arm switch, A connection path (73) electrically connects the negative terminal of the first energy storage unit or the positive terminal of the second energy storage unit to the armature winding, The neutral point capacitors (74, 75) connected to the aforementioned connection path, A parameter detection unit (85, 84, 84A, 84B, 88, 89A, 89B) for detecting electrical parameters in the neutral point capacitor or the connection path, Control devices (100, 90, 110, 130), Equipped with, The control device is a power converter that, when it is performing switching control of the inverter and supplying current to the connection path, performs a determination process to determine whether or not an electrical interruption abnormality has occurred in the connection path based on the detected value of the parameter detection unit.

2. A switch (50) between energy storage units electrically connects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned ON, and electrically disconnects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned OFF, A bypass switch (60) electrically connects the negative terminal of the first energy storage unit and the negative terminal of the second energy storage unit when turned ON, and electrically disconnects the negative terminal of the first energy storage unit and the negative terminal of the second energy storage unit when turned OFF, Equipped with, The aforementioned connection path electrically connects the armature winding and the positive terminal of the second energy storage unit. The power conversion device according to claim 1, wherein the neutral point capacitor (74) electrically connects the connection path and the low-potential side path.

3. The control device is When an external charger (210) is electrically connected to the high-potential side path and the low-potential side path, with the inter-energy storage unit switch turned OFF and the bypass switch turned ON, the upper arm switch is switched to perform an external charging control that charges the second energy storage unit by flowing current through a closed circuit including the external charger, the inverter, the armature winding, the connection path and the second energy storage unit. The power conversion device according to claim 2, wherein the determination process involves determining whether or not an electrical interruption abnormality has occurred in the portion of the connection path that is on the second energy storage unit side of the connection point with the neutral point capacitor, while the external charging control is being executed.

4. The motor-side switch (71) is provided in the portion of the connection path that is closer to the second energy storage unit than the connection point with the neutral point capacitor. The control device controls the motor-side switch to be turned ON in the external charging control, The power conversion device according to claim 3, wherein the interruption abnormality is an abnormality in which the motor-side switch is turned off.

5. The control device is With the inter-energy storage unit switch turned ON and the bypass switch turned OFF, the first control involves supplying current from the first energy storage unit to the second energy storage unit via the inverter, the armature winding, and the connection path by performing switching control of the upper arm switch. With the inter-energy storage unit switch turned ON and the bypass switch turned OFF, a second control is performed to supply current from the second energy storage unit to the first energy storage unit via the connection path, the armature winding, and the inverter by performing switching control of the lower arm switch. Perform As the aforementioned determination process, During the execution of the first control, a process is performed to determine whether or not an electrical interruption abnormality has occurred in the portion of the connection path that is on the side of the second energy storage unit than the connection point with the neutral point capacitor. During the execution of the second control, a process is performed to determine whether or not an electrical interruption abnormality has occurred in the portion of the connection path that is on the armature winding side of the connection point with the neutral point capacitor, The power conversion device according to claim 2, which performs the following:

6. Of the aforementioned connection path, the first motor-side switch (71) is provided in the portion on the side of the second energy storage unit that is closer to the connection point with the neutral point capacitor, A second motor-side switch (72) is provided in the part of the aforementioned connection path that is closer to the armature winding than the connection point with the neutral point capacitor, Equipped with, The control device, in the first control and the second control, controls the first motor-side switch and the second motor-side switch to be ON. The interruption abnormality during the execution of the first control is an abnormality in which the first motor-side switch is turned off. The power converter according to claim 5, wherein the interruption abnormality during the execution of the second control is an abnormality in which the second motor side switch is turned off.

7. The control device is When the external power supply target unit (230) is electrically connected to the high-potential side path and the low-potential side path, the external power supply control is performed by switching the lower arm switch while the inter-energy storage unit switch is turned off and the bypass switch is turned on, thereby supplying current from the second energy storage unit to the external power supply target unit via the connection path, the armature winding, and the inverter. The power converter according to claim 2, wherein the determination process involves determining whether an electrical interruption abnormality has occurred in the portion of the connection path that is on the armature winding side of the connection point with the neutral point capacitor while the external power supply control is being executed.

8. The motor-side switch (72) is provided in the portion of the connection path that is closer to the armature winding than the connection point with the neutral point capacitor. The control device controls the motor-side switch to be turned ON in the external power supply control, The power conversion device according to claim 7, wherein the interruption abnormality is an abnormality in which the motor-side switch is turned off.

9. A switch (50) between energy storage units electrically connects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned ON, and electrically disconnects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned OFF, A bypass switch (61) electrically connects the positive terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned ON, and electrically disconnects the positive terminal of the first energy storage unit and the positive terminal of the second energy storage unit when turned OFF, Equipped with, The aforementioned connection path electrically connects the armature winding and the negative terminal of the first energy storage unit. The power conversion device according to claim 1, wherein the neutral point capacitor (75) electrically connects the connection path and the high-potential side path.

10. The control device is When an external charger (210) is electrically connected to the high-potential side path and the low-potential side path, the inter-energy storage unit switch is turned OFF and the bypass switch is turned ON, and the lower arm switch is switched to perform an external charging control that charges the first energy storage unit by flowing current through a closed circuit including the external charger, the first energy storage unit, the connection path, the armature winding and the inverter. The power conversion device according to claim 9, wherein the determination process involves determining whether an electrical interruption abnormality has occurred in the portion of the connection path that is on the side of the first energy storage unit rather than the connection point with the neutral point capacitor, while the external charging control is being executed.

11. The motor-side switch (71) is provided in the portion of the connection path that is closer to the first energy storage unit than the connection point with the neutral point capacitor. The control device controls the motor-side switch to be turned ON in the external charging control, The power conversion device according to claim 10, wherein the interruption abnormality is an abnormality in which the motor-side switch is turned off.

12. The control device is With the inter-energy storage unit switch turned ON and the bypass switch turned OFF, the first control involves supplying current from the first energy storage unit to the second energy storage unit via the inverter, the armature winding, and the connection path by performing switching control of the upper arm switch. With the inter-energy storage unit switch turned ON and the bypass switch turned OFF, a second control is performed to supply current from the second energy storage unit to the first energy storage unit via the connection path, the armature winding, and the inverter by performing switching control of the lower arm switch. Perform As the aforementioned determination process, During the execution of the first control, a process is performed to determine whether or not an electrical interruption abnormality has occurred in the part of the connection path that is on the side of the first energy storage unit than the connection point with the neutral point capacitor. During the execution of the second control, a process is performed to determine whether or not an electrical interruption abnormality has occurred in the portion of the connection path that is on the armature winding side of the connection point with the neutral point capacitor, The power conversion device according to claim 9, which performs the following:

13. Of the aforementioned connection path, the first motor-side switch (71) is provided in the portion closer to the first energy storage unit than the connection point with the neutral point capacitor, A second motor-side switch (72) is provided in the part of the aforementioned connection path that is closer to the armature winding than the connection point with the neutral point capacitor, Equipped with, The control device turns on the first motor-side switch and the second motor-side switch in the first control and the second control. The interruption abnormality during the execution of the first control is an abnormality in which the first motor-side switch is turned off. The power converter according to claim 12, wherein the interruption abnormality during the execution of the second control is an abnormality in which the second motor-side switch is turned off.

14. The control device is When the external power supply target unit (230) is electrically connected to the high-potential side path and the low-potential side path, the external power supply control is performed by controlling the switching of the lower arm switch while the inter-energy storage unit switch is turned off and the bypass switch is turned on, thereby supplying current to the external power supply target unit via current to the closed circuit including the external power supply target unit, the first energy storage unit, the connection path, the armature winding and the inverter. The power converter according to claim 9, wherein the determination process involves determining whether an electrical interruption abnormality has occurred in the portion of the connection path that is on the armature winding side of the connection point with the neutral point capacitor while the external power supply control is being executed.

15. The motor-side switch (72) is provided in the portion of the connection path that is closer to the armature winding than the connection point with the neutral point capacitor. The control device controls the motor-side switch to be turned ON in the external power supply control, The power conversion device according to claim 14, wherein the interruption abnormality is an abnormality in which the motor-side switch is turned off.

16. The parameter detection unit (85) detects the terminal voltage of the neutral point capacitor, The power converter according to any one of claims 1 to 15, wherein the control device performs a determination process that calculates the rate of change (Va) of the detected terminal voltage, and determines that the interruption abnormality has occurred when the calculated rate of change exceeds a threshold (Vhth).

17. The parameter detection units (84, 84A, 84B) detect the current flowing through the connection path, The power converter according to any one of claims 1 to 15, wherein the control device performs a determination process to determine whether or not the interruption abnormality has occurred based on the detected current (IN).

18. The power conversion device according to any one of claims 1 to 15, wherein the control device stops the switching control of the inverter when it determines that the interruption abnormality has occurred.

19. A smoothing capacitor (21) connected in parallel to the series connection of the upper arm switch and the lower arm switch, Main switches (SMRH, SMRL) provided in at least one of the high-potential path and the low-potential path, Equipped with, The power conversion device according to any one of claims 1 to 15, wherein the control device, when it determines that the interruption abnormality has occurred, controls the main switch to the OFF position, then controls the switching of the inverter to discharge the smoothing capacitor, and stops the switching control of the inverter after the discharge is completed.

20. An inverter (20) having an upper arm switch (SWH) and a lower arm switch (SWL), A motor (10) having an armature winding (11) electrically connected to the low-potential terminal of the upper arm switch and the high-potential terminal of the lower arm switch, Computers (101, 91, 111, 131) and In a program applied to a power converter equipped with, The aforementioned power converter is A high-potential side path (22H) electrically connects the positive terminal of the first energy storage unit (31) and the high-potential side terminal of the upper arm switch, A low-potential side path (22L) electrically connects the negative terminal of the second energy storage unit (32) and the low-potential side terminal of the lower arm switch, A connection path (73) electrically connects the negative terminal of the first energy storage unit or the positive terminal of the second energy storage unit to the armature winding, The neutral point capacitors (74, 75) connected to the aforementioned connection path, A parameter detection unit (85, 84, 84A, 84B, 88, 89A, 89B) for detecting electrical parameters in the neutral point capacitor or the connection path, Equipped with, A program that causes the computer to perform a determination process to determine whether or not an electrical interruption abnormality has occurred in the connection path, based on the detected value of the parameter detection unit, when the inverter is performing switching control and current is flowing through the connection path.

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