Electric power conversion device and program

Abstract

To provide a technology capable of protecting an electric power conversion device from overcurrent.SOLUTION: An electric power conversion device comprises a motor 10, an inverter 20, a switch 50 between batteries, a by-pass switch 60, a connection route 73, and a motor ECU 100. The motor ECU 100 performs switching control of object switches of upper and lower arm switches SUH-SWL of the inverter 20. During execution of external charging control or external power supply control which sends current to a closed circuit including an external charger or an external power supply target unit and at least one of a first power storage unit and a second power storage unit, each ECU 90, 100, 110 performs current suppression control which sets current flowing in the closed circuit including the connection route 73 and the by-pass switch 60 to the maximum current of the electric power conversion device or lower.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, a power conversion device including an inverter and a motor electrically connected to the inverter is known. The inverter has upper and lower arm switches of multiple phases. The armature winding is electrically connected to a low potential side terminal of the upper arm switch of each phase and a high potential side terminal of the lower arm switch of each phase. Technology related to such a power conversion device is described in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-47677 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need for new technology to protect power conversion devices from overcurrents.

[0005] A primary object of the present disclosure is to provide a technique capable of protecting a power conversion device from an overcurrent. [Means for solving the problem]

[0006] The present disclosure provides an inverter having upper and lower arm switches for multiple phases; a motor having an armature winding electrically connected to a low potential side terminal of the upper arm switch of each phase and a high potential side terminal of the lower arm switch of each phase; A power conversion device comprising: a high potential side path electrically connecting a positive electrode terminal of the first power storage unit and a high potential side terminal of the upper arm switch; a low potential side path electrically connecting a negative electrode terminal of the second power storage unit and a low potential side terminal of the lower arm switch; an inter-power storage unit switch that, when turned on, electrically connects the negative electrode terminal of the first power storage unit and the positive electrode terminal of the second power storage unit and, when turned off, electrically disconnects the negative electrode terminal of the first power storage unit and the positive electrode terminal of the second power storage unit; a bypass switch that electrically connects negative electrode terminals of the first power storage unit and the second power storage unit to each other and electrically connects positive electrode terminals of the first power storage unit and the second power storage unit to each other; a connection path electrically connecting the negative terminal of the first power storage unit or the positive terminal of the second power storage unit to the armature winding; A control device that performs a current flow control, which is a switching control of a target switch that is at least one of the upper and lower arm switches, in order to flow a current through the connection path; Equipped with The control device performs a current suppression control to suppress a current flowing through a closed circuit including the connection path to a maximum current of the power conversion device or less during execution of the current flow control.

[0007] The power conversion device of the present disclosure includes a high-potential side path, a low-potential side path, an inter-storage unit switch, a bypass switch, and a connection path. In this configuration, the control device performs current flow control, which is switching control of a target switch that is at least one of the upper and lower arm switches. As a result, a current flows in a closed circuit including the connection path.

[0008] The control device performs current suppression control to suppress the current flowing through the closed circuit to a maximum current of the power conversion device or less during execution of the current flow control, thereby making it possible to protect the power conversion device from overcurrent. [Brief description of the drawings]

[0009] [Figure 1] 1 is an overall configuration diagram of a system according to a first embodiment. [Diagram 2] FIG. 4 is a diagram showing the control state of the switches during high voltage charging. [Diagram 3]FIG. 4 is a diagram showing the control state of the switches during low-voltage charging. [Figure 4] 5 is a flowchart showing the procedure of a protection process performed by the motor ECU during external charging. [Diagram 5] 4 is a flowchart showing the procedure of a protection process performed by the battery ECU during external charging. [Figure 6] 4 is a flowchart showing the procedure of a protection process performed by the EVECU during external charging. [Figure 7] 10 is a flowchart showing the procedure of a protection process by a motor ECU during external charging according to a second embodiment. [Figure 8] 4 is a flowchart showing the procedure of a protection process performed by the battery ECU during external charging. [Figure 9] 13 is a flowchart showing the procedure of a protection process performed by a motor ECU during external charging according to a third embodiment. [Figure 10] 4 is a flowchart showing the procedure of a protection process performed by the battery ECU during external charging. [Figure 11] FIG. 13 is a diagram showing a control state of a switch during high voltage power supply according to the fourth embodiment. [Figure 12] FIG. 4 is a diagram showing the control state of the switch during low voltage power supply. [Figure 13] 5 is a flowchart showing a procedure of a protection process performed by the motor ECU during external power supply. [Figure 14] 5 is a flowchart showing the procedure of a protection process performed by the battery ECU during external power supply. [Figure 15] 13 is a flowchart showing a procedure of a protection process performed by a motor ECU during external power supply according to a fifth embodiment. [Figure 16] 5 is a flowchart showing the procedure of a protection process performed by the battery ECU during external power supply. [Figure 17] 13 is a flowchart showing the procedure of a protection process performed by a motor ECU during external charging according to a sixth embodiment. [Figure 18] 4 is a flowchart showing the procedure of a protection process performed by the battery ECU during external charging. [Figure 19] FIG. 13 is an overall configuration diagram of a system according to a seventh embodiment. [Figure 20]FIG. 4 is a diagram showing the control state of the switches during low-voltage charging. [Figure 21] FIG. 4 is a diagram showing the control state of the switch during low voltage power supply. [Figure 22] 4 is a flowchart showing the procedure of a protection process performed by the battery ECU during external charging. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be given the same reference numerals. For corresponding and / or associated parts, the description of other embodiments may be referred to.

[0011] First Embodiment A first embodiment of a power conversion device according to the present invention will now be described with reference to the drawings. The power conversion device of the present embodiment is mounted on a vehicle such as an electric vehicle or a hybrid vehicle to form an on-board system.

[0012] As shown in Fig. 1, the power conversion device includes a motor 10, an inverter 20, a high-potential side path 22H, and a low-potential side path 22L. The motor 10 is a three-phase synchronous machine, and includes star-connected armature windings 11 of U, V, and W phases, and a rotor (not shown). The armature windings 11 of each phase are arranged with an electrical angle of 120°. The motor 10 is, for example, a permanent magnet synchronous machine. The rotor is capable of transmitting power to the drive wheels of the vehicle. Therefore, the motor 10 serves as a source of torque for driving the vehicle.

[0013] The inverter 20 includes three phases of series-connected upper and lower arm switches. More specifically, the inverter 20 includes U-, V-, and W-phase upper arm switches SUH, SVH, and SWH, and U-, V-, and W-phase lower arm switches SUL, SVL, and SWL. The U-, V-, and W-phase upper arm diodes DUH, DVH, and DWH, which are freewheel diodes, are connected in inverse parallel to the U-, V-, and W-phase upper arm switches SUH, SVH, and SWH, and the U-, V-, and W-phase lower arm diodes DUL, DVL, and DWL, which are freewheel diodes, are connected in inverse parallel to the U-, V-, and W-phase lower arm switches SUL, SVL, and SWL. In this embodiment, the switches SUH, SVH, SWH, SUL, SVL, and SWL are IGBTs.

[0014] The inverter 20 includes a smoothing capacitor 21. A high potential side path 22H is connected to a high potential side terminal of the smoothing capacitor 21. A low potential side path 22L is connected to a low potential side terminal of the smoothing capacitor 21. The high potential side path 22H and the low potential side path 22L are, for example, electrical paths such as bus bars. The smoothing capacitor 21 may be provided outside the inverter 20.

[0015] First ends of the U-, V-, and W-phase armature windings 11U, 11V, and 11W are connected to a connection point between emitters, which are low potential terminals of the U-, V-, and W-phase upper arm switches SUH, SVH, and SWH, and collectors, which are high potential terminals of the U-, V-, and W-phase lower arm switches SUL, SVL, and SWL, via conductive members 23 such as bus bars. Second ends of the U-, V-, and W-phase armature windings 11U, 11V, and 11W are connected to each other at a neutral point O. In this embodiment, the U-, V-, and W-phase armature windings 11U, 11V, and 11W are set to have the same number of turns. As a result, the U-, V-, and W-phase armature windings 11U, 11V, and 11W are set to have the same inductance, for example.

[0016] A high potential side path 22H is connected to the collectors of the U-, V-, and W-phase upper arm switches SUH, SVH, and SWH. A low potential side path 22L is connected to the emitters of the U-, V-, and W-phase lower arm switches SUL, SVL, and SWL.

[0017] The system includes a first storage battery 31 (corresponding to a "first power storage unit") and a second storage battery 32 (corresponding to a "second power storage unit"). Each of the storage batteries 31, 32 is a power supply source for rotating and driving the rotor of the motor 10. Each of the storage batteries 31, 32 is a battery pack including a series connection of a plurality of unit batteries. The unit battery is a single battery cell that is a single cell, or a series connection of a plurality of battery cells. In this embodiment, the full charge capacity (specifically, for example, rated full charge capacity) [Ah] of each of the unit batteries constituting the first storage battery 31 and the second storage battery 32 is the same. The positive terminal of the first storage battery 31 is connected to the high potential side path 22H via the first fuse 41, and the negative terminal of the second storage battery 32 is connected to the low potential side path 22L via the second fuse 42. The terminal voltages (for example, rated voltages) of each of the battery cells constituting the battery pack are set to be the same, for example. The battery cells are, for example, secondary batteries such as lithium ion batteries. In this embodiment, the terminal voltage (e.g., rated voltage) of the first storage battery 31 is higher than the terminal voltage (e.g., rated voltage) of the second storage battery 32. This configuration can be realized, for example, by making the number of unit batteries constituting the first storage battery 31 greater than the number of unit batteries constituting the second storage battery 32.

[0018] The power conversion device includes a main switch for electrically connecting or disconnecting the first and second storage batteries 31, 32 and the inverter 20. More specifically, a high-side main switch SMRH, a low-side main switch SMRL, and a pre-charge main switch SMRP are provided as the main switches. In this embodiment, each of the main switches SMRH, SMRL, and SMRP is a mechanical relay. When the main switches SMRH, SMRL, and SMRP are turned off, they block bidirectional current flow, and when turned on, they allow bidirectional current flow. The high-side main switch SMRH connects the high-side fuse 41 and the high-side path 22H. The low-side main switch SMRL connects the low-side fuse 42 and the low-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-side main switch SMRL. The main switches SMRH, SMRL, and SMRP are not limited to mechanical relays, and may be, for example, semiconductor switching elements.

[0019] Each of the storage batteries 31, 32 can be charged by an external charger provided outside the vehicle through external charging control. The external charger is, for example, a stationary external charger.

[0020] Each of the storage batteries 31 and 32 can supply power to a power supply target unit outside the vehicle through external power supply control. When the power supply target unit is a system power source, the external power supply control is also called V2G (Vehicle to Grid). When the power supply target unit is an electrical device in a building such as a residence, the external power supply control is also called V2H (Vehicle to Home).

[0021] The power conversion device includes a high potential side connection switch DCRH and a low potential side connection switch DCRL for electrically connecting or disconnecting between an external charger or a power supply target unit and the first and second storage batteries 31, 32. In this embodiment, each of the connection switches DCRH, DCRL is a mechanical relay. When each of the connection switches DCRH, DCRL is turned off, it blocks the flow of bidirectional current, and when each of the connection switches DCRH, DCRL is turned on, it allows the flow of bidirectional current. The high potential side connection switch DCRH is connected to the high potential side path 22H, and the low potential side connection switch DCRL is connected to the low potential side path 22L. Note that each of the connection switches DCRH, DCRL is not limited to a mechanical relay, and may be, for example, a semiconductor switching element.

[0022] The power conversion device includes an inter-battery switch 50 (corresponding to an "inter-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 as components for switching the connection state of the first storage battery 31 and the second storage battery 32. In this embodiment, the inter-battery switch 50, the bypass switch 60, and each of the motor-side switches 71, 72 are mechanical relays. When the inter-battery switch 50, the bypass switch 60, and each of the motor-side switches 71, 72 are turned off, they block the flow of bidirectional current, and when they are turned on, they allow the flow of bidirectional current. Note that the inter-battery switch 50, the bypass switch 60, and each of the motor-side switches 71, 72 are not limited to mechanical relays, and may be, for example, semiconductor switching elements.

[0023] The inter-battery switch 50 connects the negative terminal of the first storage battery 31 and the positive terminal of the second storage battery 32. When the inter-battery switch 50 is turned on, the negative terminal of the first storage battery 31 and the positive terminal of the second storage battery 32 are electrically connected. On the other hand, when the inter-battery switch 50 is turned off, the negative terminal of the first storage battery 31 and the positive terminal of the second storage battery 32 are electrically disconnected.

[0024] The bypass switch 60 connects the negative terminal of the first storage battery 31 and the low potential side path 22L. When the bypass switch 60 is turned on, the negative terminal of the first storage battery 31 and the negative terminal of the second storage battery 32 are electrically connected to each other. On the other hand, when the bypass switch 60 is turned off, the negative terminal of the first storage battery 31 and the negative terminal of the second storage battery 32 are electrically disconnected from each other.

[0025] In this embodiment, the first storage battery 31 and the second storage battery 32 configure a battery unit 30.

[0026] The connection path 73 is an electrical path that connects the positive terminal of the second storage battery 32 and the neutral point O. A first motor-side switch 71 and a second motor-side switch 72 are provided in this order from the second storage battery 32 on the connection path 73.

[0027] The power conversion device includes a neutral point capacitor 74 that is a capacitor that connects the connection path 73 and the low potential side path 22L. A first end of the neutral point capacitor 74 is connected to a portion of the connection path 73 between the first motor side switch 71 and the second motor side switch 72. A second end of the neutral point capacitor 74 is connected to the low potential side path 22L.

[0028] By turning on the first motor side switch 71, the first end of the neutral point capacitor 74 and the positive terminal of the second storage battery 32 are electrically connected. On the other hand, by turning off the first motor side switch 71, the first end of the neutral point capacitor 74 and the positive terminal of the second storage battery 32 are electrically disconnected. By turning on the second motor side switch 72, the neutral point O of the armature winding 11 and the first end of the neutral point capacitor 74 are electrically connected. On the other hand, by turning off the second motor side switch 72, the neutral point O and the first end of the neutral point capacitor 74 are electrically disconnected.

[0029] The power conversion device includes a first current sensor 81A, a second current sensor 81B, a phase current sensor 82, and a motor current sensor 83 as current sensors for detecting currents flowing through various parts of the power conversion device. The first current sensor 81A detects a current flowing through the first storage battery 31, and the second current sensor 81B detects a current flowing through the second storage battery 32. The phase current sensor 82 detects a current flowing through the U-, V-, and W-phase armature windings 11U, 11V, and 11W. The motor current sensor 83 detects a current flowing through the connection path 73, and in this embodiment, detects a current flowing through a portion of the connection path 73 that is closer to the neutral point O than the connection point with the neutral point capacitor 74.

[0030] The power conversion device includes a capacitor voltage sensor 84 that detects the terminal voltage of the neutral point capacitor 74, a first voltage sensor 85A that detects the terminal voltage of the first storage battery 31, and a second voltage sensor 85B that detects the terminal voltage of the second storage battery 32. The power conversion device also includes a power supply voltage sensor 86 that detects the terminal voltage of the smoothing capacitor 21, a battery temperature sensor 87 that detects the temperatures of the first storage battery 31 and the second storage battery 32, a rotation angle sensor 88 that detects the rotation angle (electrical angle) of the rotor, and an inverter temperature sensor 89 that detects the temperature of the inverter 20.

[0031] The system includes a battery ECU 90 that controls the battery unit 30, a motor ECU 100 that controls the inverter 20, and an EVECU 110 that manages the system. The battery ECU 90 is an electronic control unit mainly composed of a microcomputer 91. The motor ECU 100 is an electronic control unit mainly composed of a microcomputer 101. The EVECU 110 is an electronic control unit mainly composed of a microcomputer 111, and is a higher-level control unit than the battery ECU 90 and the motor ECU 100. The battery ECU 90, the motor ECU 100, and the EVECU 110 are capable of exchanging information with one another.

[0032] Each of the microcomputers 91, 101, and 111 includes a CPU (Central Processing Unit). The functions provided by each of the microcomputers 91, 101, and 111 can be provided by software recorded in a substantial memory device and a computer that executes the software, by software alone, by hardware alone, or by a combination of these. For example, when each of the microcomputers 91, 101, and 111 is provided by an electronic circuit that is hardware, the function can be provided by a digital circuit including a large number of logic circuits, or by an analog circuit. For example, each of the microcomputers 91, 101, and 111 executes a program stored in a non-transitory tangible storage medium as a storage unit provided in the microcomputer. The program includes, for example, a program of a process shown in FIG. 4, which will be described later. A set of instructions that constitute the program is executed, thereby executing a method corresponding to the program. The storage unit is, for example, a non-volatile memory. The program stored in the storage unit can be updated via a communication network such as the Internet, for example, OTA (Over The Air), etc.

[0033] The battery ECU 90 receives detection values ​​from a first current sensor 81A, a second current sensor 81B, a first voltage sensor 85A, a second voltage sensor 85B, and a battery temperature sensor 87. The motor ECU 100 receives detection values ​​from a phase current sensor 82, a motor current sensor 83, a capacitor voltage sensor 84, a power supply voltage sensor 86, a rotation angle sensor 88, and an inverter temperature sensor 89.

[0034] The motor ECU 100 performs switching control of the upper and lower arm switches SUH-SWL of each phase constituting the inverter 20 to feedback control the control amount of the motor 10 to a command value based on the detection values ​​of each sensor. The control amount is, for example, torque. In each phase, the upper arm switch and the lower arm switch are alternately turned on. Through this feedback control, the rotational power of the rotor of the motor 10 is transmitted to the drive wheels, causing the vehicle to run.

[0035] The main switches SMRH, SMRL, SMRP, the inter-battery switch 50, the bypass switch 60, and the motor-side switches 71, 72 may be controlled by any one of the battery ECU 90, the motor ECU 100, or the EVECU 110, or may be controlled by an ECU other than the ECUs 90, 100, 110. In this embodiment, hereinafter, it is assumed that the main switches SMRH, SMRL, SMRP, the inter-battery switch 50, and the bypass switch 60 are controlled by the battery ECU 90, the first motor-side switch 71 and the second motor-side switch 72 are controlled by the motor ECU 100, and the high potential side connection switch DCRH and the low potential side connection switch DCRL are controlled by the EVECU 110.

[0036] Next, the external charging control will be described.

[0037] In this embodiment, the external charger is a high-voltage charger 200 or a low-voltage charger 210, as shown in Figs. 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-connected body of the first and second storage batteries 31 and 32, and is, for example, 800V. The charging voltage of the low-voltage charger 210 is lower than the terminal voltage of the series-connected body of the first and second storage batteries 31 and 32 and higher than the terminal voltage (specifically, the rated voltage) of the first storage battery 32, and is, for example, 400V. When the first and second storage 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 on. On the other hand, when charging by the external charger is not performed or when the external charger is not connected to the power conversion device, the high-potential side connection switch DCRH and the low-potential side connection switch DCRL are switched off.

[0038] 2 shows the control state of each switch during external charging control using the high-voltage charger 200. The high-voltage charger 200 and the power conversion device are electrically connected when the charging plug of the high-voltage charger 200 is electrically connected to each connection switch DCRH, DCRL by the vehicle user. When the EVECU 110 determines that the external charger connected to the power conversion device is the high-voltage charger 200, it notifies the battery ECU 90 and the motor ECU 100 of the execution of high-voltage charging control by the high-voltage charger 200, thereby turning off the pre-charge main switch SMRP, the bypass switch 60, the first motor side switch 71, the second motor side switch 72, and the upper and lower arm switches SUH to SWL of all phases of the inverter 20, and turning on the high potential side main switch SMRH, the low potential side main switch SMRL, and the inter-battery switch 50. As a result, the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage charger 200. As a result, a current flows through a closed circuit including the high-voltage charger 200, the high-potential side path 22H, the first storage battery 31, the inter-battery switch 50, the second storage battery 32, and the low-potential side path 22L, and the first storage battery 31 and the second storage battery 32 are charged in a state of being connected in series. At this time, since the upper arm switches SUH, SVH, SWH of the inverter 20 and the second motor-side switch 72 are turned off, it is possible to prevent the charging current of the high-voltage charger 200 from flowing to the inverter 20 and the armature winding 11.

[0039] 3 shows the control state of each switch during external charging control using the low-voltage charger 210. The low-voltage charger 210 and the power conversion device are electrically connected by electrically connecting the charging plug of the low-voltage charger 210 to each connection switch DCRH, DCRL by the vehicle user. When the EVECU 110 determines that the external charger connected to the power conversion device is the low-voltage charger 210, it notifies the battery ECU 90 and the motor ECU 100 of the execution of low-voltage charging control by the low-voltage charger 210, thereby turning off the pre-charge main switch SMRP and the inter-battery switch 50, and turning on the high-potential side main switch SMRH, the low-potential side main switch SMRL, the bypass switch 60, the first motor side switch 71, and the second motor side switch 72. As a result, a current flows through a closed circuit including the low-voltage charger 210, the high-potential side path 22H, the first storage battery 31, the bypass switch 60, and the low-potential side path 22L, and the first storage battery 31 is charged.

[0040] In the external charging control by the low-voltage charger 210, the motor ECU 100 performs switching control to alternately turn on upper and lower arm switches (corresponding to "target switches") of at least one phase, or performs switching control of an upper arm switch (corresponding to "target switch") of at least one phase with the lower arm switches SUL, SVL, and SWL of all phases of the inverter 20 turned off, thereby stepping down the output voltage of the low-voltage charger 210 and supplying it to the second storage battery 32. In detail, the motor ECU 100 performs step-down control, which is the above-mentioned switching control for controlling the voltage detected by the capacitor voltage sensor 84 (hereinafter, neutral point capacitor voltage VN) to a target charging voltage. As a result, a current flows through a closed circuit including the low-voltage charger 210, the high potential side path 22H, the upper arm switch 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 storage battery 32, and the low potential side path 22L, and the second storage battery 32 is charged. Since the terminal voltage of the second storage battery 32 is lower than the terminal voltage of the first storage battery 31 , the target charging voltage of the second storage battery 32 is lower than the target charging voltage of the first storage battery 31 .

[0041] In this embodiment, the battery ECU 90, the motor ECU 100, and the EVECU 110 cooperate to execute current suppression control to protect the power conversion device and each of the storage batteries 31, 32 from an overcurrent.

[0042] The motor ECU 100 is configured to be able to execute the following processes M1 to M3 as processes related to the current suppression control. (M1) Decrease the duty ratio of the inverter 20 (M2) Turn off the second motor side switch 72 (M3) The EVECU 110 is notified that the current flowing through the armature windings and the inverter 20 needs to be restricted. In process M1, the duty ratio Duty is the ratio (Ton / Tsw) of an on-period Ton to one switching period Tsw of a switch (specifically, an upper arm switch which is a target switch). For each of the U, V, and W phases, gate signals for the upper and lower arm switches are generated based on the duty ratio Duty, and step-down control of the inverter 20 is performed based on the generated gate signals. Therefore, according to process M1, it is possible to reduce the current flowing through the inverter 20 and each armature winding 11U, 11V, and 11W.

[0043] When the process M2 is executed, the flow of current is interrupted in the connection path 73. This makes it possible to interrupt the current flowing through the inverter 20 and each of the armature windings 11U, 11V, 11W.

[0044] In process M3, the EVECU 110 is notified that current suppression is required for the current flowing through the inverter 20 or each armature winding 11U, 11V, 11W, which are controlled by the motor ECU 100. As will be described later, the EVECU 110 performs a process to reduce the output power of the external charger, so that the current flowing through the inverter 20 or each armature winding 11U, 11V, 11W can be reduced. Process M3 is a process to indirectly reduce the output of the external charger.

[0045] The battery ECU 90 is configured to be able to execute the following processes B1 to B4 as the current suppression control process. (B1) Turn off at least one of the main switches SMRH and SMRL. (B2) Notify the EVECU 110 that the current flowing through the battery having the higher inter-terminal voltage (the first battery 31 in this embodiment) out of the first and second batteries 31, 32 needs to be suppressed. (B3) Notifying the motor ECU 100 of execution of at least one of the processes M1 and M2 (B4) The EVECU 110 is notified that it is necessary to suppress the current flowing through one of the first and second storage batteries 31, 32 having a lower inter-terminal voltage (the second storage battery 32 in this embodiment).

[0046] In process B1, by turning off the high potential side main switch SMRH, the flow of current in the high potential side path 22H can be interrupted. By turning off the low potential side main switch SMRL, the flow of current in the low potential side path 22L can be interrupted. By turning off the high potential side main switch SMRH, the current flowing to the first storage battery 31 and the second storage battery 32 can be interrupted during high voltage charging shown in FIG. 2 by turning off the high potential side main switch SMRH. By turning off the high potential side main switch SMRH, the current flowing to the first storage battery 31 can be interrupted during low voltage charging shown in FIG. 3. Note that, by turning off at least one of the main switches SMRH and SMRL, the current flowing to the first storage battery 31 and the second storage battery 32 can be interrupted during high voltage charging shown in FIG. 2.

[0047] When process B2 is executed, as described below, the EVECU 110 performs a process of reducing the output current and / or output voltage of the external charger, thereby reducing the current flowing to the first storage battery 31. Process B2 is a process of indirectly reducing the output of the external charger.

[0048] In process B3, execution of at least one of processes M1 and M2 is notified to the motor ECU 100. According to processes M1 and M2, the current flowing through the second storage battery 32 during low-voltage charging shown in FIG.

[0049] When process B4 is executed, as described below, the EVECU 110 performs a process of reducing the output power of the external charger, thereby reducing the current flowing to the second storage battery 32. Process B4 is a process of indirectly reducing the output of the external charger.

[0050] Processes B1 to B4 include a process for suppressing both the current flowing through the first storage battery 31 and the current flowing through the second storage battery 32, and a process for suppressing only one of them. The battery ECU 90 may be configured to combine the processes shown in processes B1 to B4 or to select process contents more specific than those shown in processes B1 and B3 so that the current suppression control is executed only for the storage battery that requires the current suppression control, out of the first and second storage batteries 31 and 32.

[0051] For example, when the process B3 is executed during the low-voltage charging shown in FIG. 3, the current flowing through the second storage battery 32 can be suppressed, but the current flowing through the first storage battery 31 cannot be suppressed. For this reason, in order to suppress the current flowing through both the first and second storage batteries 31, 32 during the low-voltage charging shown in FIG. 3, it is preferable to execute the process B3 in combination with a process capable of suppressing the current flowing through the first storage battery 31, such as the process B1. Also, for example, when the process B1 is executed as the process B1 for turning off only the high-potential side main switch SMRH during the low-voltage charging shown in FIG. 3, the current flowing through the first storage battery 31 can be suppressed, but the current flowing through the second storage battery 32 cannot be suppressed. By combining the processes B1 and B3 during the low-voltage charging shown in FIG. 3, it is possible to handle three cases, that is, a case in which only the current flowing through the first storage battery 31 is suppressed, a case in which only the current flowing through the second storage battery 32 is suppressed, and a case in which both the current flowing through the first storage battery 31 and the current flowing through the second storage battery 32 are suppressed.

[0052] The EVECU 110 performs a current suppression control process when receiving a notification from the battery ECU 90 and the motor ECU 100. The EVECU 110 is configured to be able to execute the following process E1 as the current suppression control process. (E1) Reduce the output power of the external charger.

[0053] The EVECU 110 reduces the output power of the external charger by controlling the external charger. Specifically, for example, the EVECU 110 reduces the output power by reducing at least one of the output current and the output voltage of the external charger. The EVECU 110 may control the external charger so that the output current and the output voltage become zero. After reducing the output power of the external charger, the EVECU 110 may turn off at least one of the high potential side connection switch DCRH and the low potential side connection switch DCRL.

[0054] When the process E1 is executed, the current restriction control is executed for both the first and second storage batteries 31, 32. For this reason, the EVECU 110 may be configured to execute the process E1 when the EVECU 110 receives a notification from the battery ECU 90 that the current restriction control is required for both the first and second storage batteries 31, 32, and not to execute the process E1 when the EVECU 110 receives a notification from the battery ECU 90 that the current restriction control is required for only one of the first and second storage batteries 31, 32 and the other does not.

[0055] In this embodiment, using Figures 4 to 6, the current suppression control processing executed by each ECU will be specifically explained by taking as an example a case in which the charging current, which is the current flowing through each component (specifically, each armature winding 11U, 11V, 11W, inverter 20, first storage battery 31 and second storage battery 32) during execution of external charging control by the low-voltage charger 210, as a parameter.

[0056] 4 is a flowchart showing the procedure of the current suppression control process executed by the motor ECU 100. This process is repeatedly executed by the motor ECU 100, for example, at a predetermined control period.

[0057] In step S101, it is determined whether or not a phase current detection value Ipd, which is the phase current having the largest absolute value among the phase currents of the phases detected by the phase current sensor 82, is greater than a phase current threshold Ipth. The phase current threshold Ipth is set to a current value that does not exceed the maximum current allowed by the inverter 20 or the motor 10 (for example, the maximum rated current of the inverter 20 or the motor 10). If it is determined that Ipd>Ipth, the process proceeds to step S102. On the other hand, if it is determined that Ipd≦Ipth, the process proceeds to step S103.

[0058] In step S102, at least one of the above-mentioned processes M1 to M3 is executed as a protection process by the motor ECU 100. Then, the process ends.

[0059] In step S103, it is determined whether or not a notification regarding current suppression has been received from the battery ECU 90. If a notification has been received, the process proceeds to step S104, where at least one of the above processes M1 and M2 is executed, and then the process ends. Note that, for example, it is sufficient if the battery ECU 90 notifies the user which of the processes M1 and M2 should be executed. If no notification has been received, the process ends.

[0060] Incidentally, the processes in steps S103 and S104 may be omitted from the process shown in Fig. 4. In this case, if a negative determination is made in step S101, the process may be ended as it is.

[0061] 5 is a flowchart showing the procedure of the current suppression control process executed by the battery ECU 90. This process is repeatedly executed by the battery ECU 90 at a predetermined control period, for example.

[0062] In step S111, it is determined whether or not the first current detection value Ibd1, which is the current value detected by the first current sensor 81A, is higher than the first charging current threshold Ichrth1. The first charging current threshold Ichrth1 is set, for example, to a current value that does not exceed the maximum charging current allowed by the first storage battery 31 (for example, the maximum rated current on the charging side of the first storage battery 31). If it is determined that Ibd1>Ichrth1, the process proceeds to step S112. On the other hand, if it is determined that Ibd1≦Ichrth1, the process proceeds to step S113.

[0063] In step S112, at least one of the above-mentioned processes B1 and B2 is executed as a protection process by the battery ECU 90. Note that since the storage battery with the higher inter-terminal voltage is the first storage battery 31, the process B2 is a process to notify the EVECU 110 that the current flowing through the first storage battery 31 needs to be suppressed. Then, the process proceeds to step S113.

[0064] According to process B1, during low-voltage charging as shown in Fig. 3, by turning off only the high potential side main switch SMRH, it is possible to cut off only the current flowing to the first storage battery 31. Note that in this embodiment, in step S112, no determination result is obtained for the second storage battery 32. For this reason, in step S112, for example, process B1 may be executed to turn off only the high potential side main switch SMRH, thereby suppressing only the current flowing to the first storage battery 31.

[0065] In step S113, it is determined whether the second current detection value Ibd2, which is the current value detected by the second current sensor 81B, is higher than the second charging current threshold Ichrth2. The second charging current threshold Ichrth2 is set to a current value that does not exceed the maximum charging current allowed by the second storage battery 32, for example. If it is determined that Ibd2>Ichrth2, the process proceeds to step S114. On the other hand, if it is determined that Ibd2≦Ichrth2, the process ends.

[0066] In step S114, at least one of the above processes B3 and B4 is executed as a protection process by the battery ECU 90. Since the storage battery with the lower inter-terminal voltage is the second storage battery 32, the process B4 is a process to notify the EVECU 110 that the current flowing through the second storage battery 32 needs to be suppressed. Then, the process ends.

[0067] 6 is a flowchart showing the procedure of the current suppression control process executed by the EVECU 110. This process is repeatedly executed by the EVECU 110, for example, at a predetermined control period.

[0068] In step S121, it is determined whether or not a notification regarding current suppression has been received from the motor ECU 100 or the battery ECU 90. If it is determined that a notification has been received, the process proceeds to step S122, where the above-mentioned process E1 is executed, and the process ends. If no notification has been received, the process ends.

[0069] Steps S121 and S122 may be configured to execute processing E1 when a notification is received from the battery ECU 90 that current suppression control is required for both the first and second storage batteries 31, 32, and to not execute processing E1 when a notification is received from the battery ECU 90 that current suppression control is required for only one of the first and second storage batteries 31, 32 and the other does not require current suppression control.

[0070] It is sufficient that the charging power of the second storage battery 32 is kept equal to or less than the maximum charging power of the second storage battery 32 by the current suppression control described above.

[0071] According to the present embodiment described above, it is possible to protect the components of the power conversion device and the storage battery from overcurrent while external charging control is being executed.

[0072] <Second embodiment> The second embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, power is used in the current suppression control instead of current. The current suppression control of this embodiment will be described below with reference to Figs. 6 to 8.

[0073] 7 is a flowchart showing the procedure of the current suppression control process executed by the motor ECU 100. This process is repeatedly executed by the motor ECU 100, for example, at a predetermined control period.

[0074] In step S131, it is determined whether or not a phase power value Wpd, which is the power with the largest absolute value among the powers transmitted through each phase, is greater than a phase power threshold value Wpth. The phase power value Wpd may be calculated, for example, based on the detection value of the phase current sensor 82 and the voltage value detected by the power supply voltage sensor 86. The phase power threshold value Wpth is set, for example, to a power value that does not exceed the maximum power allowed by the inverter 20 or the motor 10 (for example, the maximum rated power of the inverter 20 or the motor 10). If it is determined that Wpd>Wpth, the process proceeds to step S132. On the other hand, if it is determined that Wpd≦Wpth, the process proceeds to step S133.

[0075] In step S132, at least one of the above processes M1 to M3 is executed as a protection process by the motor ECU 100. Then, the process ends. In step S133, it is determined whether or not there has been a notification from the battery ECU 90 regarding current suppression. If there has been a notification, the process proceeds to step S134, where at least one of the above processes M1 and M2 is executed, and then the process ends. Note that, for example, it is sufficient if the battery ECU 90 notifies the user which of the processes M1 and M2 should be executed. If there has been no notification, the process ends as it is.

[0076] Incidentally, the processes of steps S133 and S134 may be omitted from the process shown in Fig. 7. In this case, if a negative determination is made in step S131, the process may be ended as it is.

[0077] 8 is a flowchart showing the procedure of the current suppression control process executed by the battery ECU 90. This process is repeatedly executed by the battery ECU 90 at a predetermined control period, for example.

[0078] In step S141, it is determined whether or not the charging power Wbchr1 of the first storage battery 31 is higher than the first charging power threshold Wchrth1. The charging power Wbchr1 of the first storage battery 31 may be calculated, for example, based on the detection value of the first current sensor 81A and the detection value of the first voltage sensor 85A. The first charging power threshold Wchrth1 is set, for example, to a power value that does not exceed the maximum charging power permitted by the first storage battery 31 (for example, the maximum rated power of the charging side of the first storage battery 31). If it is determined that Wbchr1>Wchrth1, the process proceeds to step S142. On the other hand, if it is determined that Wbchr1≦Wchrth1, the process proceeds to step S143.

[0079] In step S142, at least one of the above-mentioned processes B1 and B2 is executed as a protection process by the battery ECU 90. Then, the process proceeds to step S143.

[0080] In step S143, it is determined whether the charging power Wbchr2 of the second storage battery 32 is higher than the second charging power threshold Wchrth2. The charging power Wbchr2 of the second storage battery 32 may be calculated, for example, based on the detection value of the second current sensor 81B and the detection value of the second voltage sensor 85B. The second charging power threshold Wchrth2 is set, for example, to a power value that does not exceed the maximum charging power allowed by the second storage battery 32 (for example, the maximum rated power of the charging side of the second storage battery 32). If it is determined that Wbchr2>Wchrth2, the process proceeds to step S144. On the other hand, if it is determined that Wbchr2≦Wchrth2, the process ends.

[0081] In step S144, at least one of the above-mentioned processes B3 and B4 is executed as a protection process by the battery ECU 90. Then, the process ends.

[0082] Even when power is used as a parameter instead of current as shown in FIGS. 7 and 8, the EVECU 110 executes the same process as that shown in FIG.

[0083] According to the present embodiment described above, it is possible to achieve the same effects as the first embodiment.

[0084] <Third embodiment> The third embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, temperature is used instead of current in the current suppression control. The current suppression control of this embodiment will be described below with reference to Figs. 6, 9, and 10, and Figs. 9, 10, and 6.

[0085] 9 is a flowchart showing the procedure of the current suppression control process executed by the motor ECU 100. This process is repeatedly executed by the motor ECU 100, for example, at a predetermined control period.

[0086] In step S151, it is determined whether or not the inverter temperature detection value Tid, which is the temperature detected by the inverter temperature sensor 89, is higher than the inverter temperature threshold Tith. The inverter temperature sensor 89 detects the temperature of the elements constituting the inverter 20. For example, it is preferable that the inverter temperature threshold Tith is set as a temperature threshold corresponding to the elements to be detected by the inverter temperature sensor 89. For example, when the inverter temperature sensor 89 detects the temperature of the IGBTs constituting each of the switches SUH to SWL of the inverter 20 as the temperature detection value Tid, it is preferable that the inverter temperature threshold Tith is set to a value that does not exceed the heat resistance temperature of the IGBTs constituting each of the switches SUH to SWL of the inverter 20. If it is determined that Tid>Tith, the process proceeds to step S152. On the other hand, if it is determined that Tid≦Tith, the process proceeds to step S153.

[0087] In step S152, at least one of the above-mentioned processes M1 to M3 is executed as a protection process by the motor ECU 100. Thereafter, the process ends.

[0088] In step S153, it is determined whether or not a notification regarding current suppression has been received from the battery ECU 90. If a notification has been received, the process proceeds to step S154, where at least one of the above processes M1 and M2 is executed, and then the process ends. Note that, for example, it is sufficient if the battery ECU 90 notifies the user which of the processes M1 and M2 should be executed. If no notification has been received, the process ends.

[0089] 10 is a flowchart showing the procedure of the current suppression control process executed by the battery ECU 90. This process is repeatedly executed by the battery ECU 90 at a predetermined control period, for example.

[0090] In step S161, it is determined whether a first temperature detection value Tbd1, which is the temperature of the first storage battery 31 detected by the battery temperature sensor 87, is higher than a first temperature threshold value Tbth1. The first temperature threshold value Tbth1 is set to a value that does not exceed the heat resistance temperature of the first storage battery 31, for example. If it is determined that Tbd1>Tbth1, the process proceeds to step S162. On the other hand, if it is determined that Tbd1≦Tbth1, the process proceeds to step S163.

[0091] In step S162, at least one of the above-mentioned processes B1 and B2 is executed as a protection process by the battery ECU 90. Then, the process proceeds to step S163.

[0092] In step S163, it is determined whether or not a second temperature detection value Tbd2, which is the temperature of the second storage battery 32 detected by the battery temperature sensor 87, is higher than a second temperature threshold value Tbth2. The second temperature threshold value Tbth2 is set to a value that does not exceed the heat resistance temperature of the second storage battery 32, for example. If it is determined that Tbd2>Tbth2, the process proceeds to step S164. On the other hand, if it is determined that Tbd2≦Tbth2, the process ends.

[0093] In step S164, at least one of the above-mentioned processes B3 and B4 is executed as the protection process by the battery ECU 90. Then, the process ends.

[0094] Even when temperature is used as a parameter as shown in FIGS. 9 and 10, instead of when current is used as a parameter as shown in FIGS. 4 and 5, the EVECU 110 executes the same process as that shown in FIG.

[0095] According to the present embodiment described above, it is possible to protect the components of the power conversion device and the storage battery from overcurrent.

[0096] <Fourth embodiment> Hereinafter, the fourth embodiment will be described with reference to the drawings, focusing on the differences from the first to third embodiments. In the fourth embodiment, a case where external power supply control is performed will be described.

[0097] 11 shows the control state of each switch during external power supply control in which power is supplied from the first and second storage batteries 31 and 32 to the high-voltage power supply target 220. When the EVECU 110 determines that the power supply target connected to the power conversion device is the high-voltage power supply target 220, it notifies the battery ECU 90 and the motor ECU 100 of the execution of high-voltage power supply control, thereby turning off the pre-charge main switch SMRP, the bypass switch 60, the first motor side switch 71, the second motor side switch 72, and the upper and lower arm switches SUH to SWL of all phases of the inverter 20, and turning on the high potential side main switch SMRH, the low potential side main switch SMRL, and the inter-battery switch 50. As a result, the first storage battery 31 and the second storage battery 32 are connected in series to the high-voltage power supply target 220. As a result, current flows through a closed circuit including the first storage battery 31, the high potential side path 22H, the high voltage power supply target section 220, the low potential side path 22L and the second storage battery 32, and power is supplied from the first storage battery 31 and the second storage battery 32 to the high voltage power supply target section 220.

[0098] 12 shows the control state of each switch during external power supply control in which power is supplied from the first and second storage batteries 31, 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 EVECU 110 determines that the power supply target unit connected to the power conversion device is the low-voltage power supply target unit 230, it notifies the battery ECU 90 and the motor ECU 100 of the execution of low-voltage power supply control, thereby turning off the pre-charge main switch SMRP and the inter-battery switch 50, and turning on the high potential side main switch SMRH, the low potential side main switch SMRL, the bypass switch 60, the first motor side switch 71, and the second motor side switch 72. As a result, current flows through a closed circuit including the first storage battery 31, the high potential side path 22H, the low voltage power supply target 230, the low potential side path 22L and the bypass switch 60, and power is supplied from the first storage battery 31 to the low voltage power supply target 230.

[0099] In the external power supply control for the low-voltage power supply target portion 230, the motor ECU 100 performs switching control for alternately turning on upper and lower arm switches (corresponding to "target switches") of at least one phase, or performs switching control for a lower arm switch (corresponding to "target switches") of at least one phase in a state in which the upper arm switches SUH, SVH, and SWH of all phases of the inverter 20 are turned off, thereby boosting the output voltage of the second storage battery 32 and supplying it to the low-voltage power supply target portion 230. In detail, the motor ECU 100 performs boost control, which is the switching control for controlling the power supply voltage VB, which is the detection voltage of the power supply voltage sensor 86, to a target power supply voltage. As a result, a current flows through a closed circuit including the second storage battery 32, the connection path 73, the armature winding 11, the inverter 20, the high potential side path 22H, the low-voltage power supply target portion 230, and the low potential side path 22L, and power is supplied from the second storage battery 32 to the low-voltage power supply target portion 230.

[0100] Next, the current suppression control during external power supply control will be described. During external power supply control, the EVECU 110 does not execute the current suppression control process. Therefore, the battery ECU 90 and the motor ECU 100 do not execute the processes (M3, B2, B4) of the above processes M1 to M3 and B1 to B4 for notifying the EVECU 110 that the current needs to be suppressed. The battery ECU 90 is configured to be able to execute the above process B1 or B3 as the current suppression control process. The motor ECU 100 is configured to be able to execute the above process M1 or M2 as the process related to the current suppression control. Even during external power supply control, the detection values ​​of the parameters and the threshold values ​​corresponding to the parameters described in the first to third embodiments can be used.

[0101] 13 is a flowchart showing the procedure of the current suppression control process executed by the motor ECU 100. This process is repeatedly executed by the motor ECU 100, for example, at a predetermined control period.

[0102] In step S201, it is determined whether or not the phase current detection value Ipd is higher than the phase current threshold value Ipth. If it is determined that Ipd>Ipth, the process proceeds to step S203. On the other hand, if it is determined that Ipd≦Ipth, the process proceeds to step S202.

[0103] In step S202, it is determined whether or not a notification regarding current suppression has been received from the battery ECU 90. If a notification has been received, the process proceeds to step S203. If no notification has been received, the process ends.

[0104] In step S203, at least one of the above-mentioned processes M1 and M2 is executed as a protection process by the motor ECU. Then, the process ends. In the process M1 during the execution of the external power supply control, the duty ratio Duty of the lower arm switch is reduced, not that of the upper arm switch.

[0105] 14 is a flowchart showing the procedure of the current suppression control process executed by the battery ECU 90. This process is repeatedly executed by the battery ECU 90 at a predetermined control period, for example.

[0106] In step S211, it is determined whether the first current detection value Ibd1 is higher than the first discharge current threshold Idisth1. The first discharge current threshold Idisth1 is set, for example, to a current value that does not exceed the maximum discharge current allowed by the first storage battery 31 (for example, the maximum rated current on the discharge side of the first storage battery 31). If it is determined that Ibd1>Idisth1, the process proceeds to step S212. On the other hand, if it is determined that Ibd1≦Idisth1, the process proceeds to step S213.

[0107] In step S212, the above-mentioned process B1 is executed as the protection process by the battery ECU 90. After that, the process proceeds to step S213.

[0108] In step S213, it is determined whether the second current detection value Ibd2 is higher than the second discharge current threshold Idisth2. The second discharge current threshold Idisth2 is set, for example, to a current value that does not exceed the maximum discharge current permitted by the second storage battery 32 (for example, the maximum rated current on the discharge side of the second storage battery 32). If it is determined that Ibd2>Idisth2, the process proceeds to step S214. On the other hand, if it is determined that Ibd2≦Idisth2, the process ends.

[0109] In step S214, the above-mentioned process B3 is executed as the protection process by the battery ECU 90. Then, the process ends.

[0110] According to the present embodiment described above, it is possible to protect the components of the power conversion device and the storage battery from an overcurrent while the external power supply control is being executed.

[0111] <Fifth embodiment> Hereinafter, the fifth embodiment will be described with reference to the drawings, focusing on the differences from the fourth embodiment. In this embodiment, power is used instead of current in the current suppression control. Hereinafter, the current suppression control of this embodiment will be described with reference to FIGS. 15 and 16.

[0112] 15 is a flowchart showing the procedure of the current suppression control process executed by the motor ECU 100. This process is repeatedly executed by the motor ECU 100, for example, at a predetermined control period.

[0113] In step S221, it is determined whether or not the phase power value Wpd is higher than the phase power threshold value Wpth. If it is determined that Wpd>Wpth, the process proceeds to step S223. On the other hand, if it is determined that Wpd≦Wpth, the process proceeds to step S222.

[0114] In step S222, it is determined whether or not a notification regarding current suppression has been received from the battery ECU 90. If a notification has been received, the process proceeds to step S223. If no notification has been received, the process ends.

[0115] In step S223, at least one of the above-mentioned processes M1 and M2 is executed as a protection process by the motor ECU 100. Then, the process ends. In the process M1 during the execution of the external power supply control, the duty ratio Duty of the lower arm switch is reduced, not that of the upper arm switch.

[0116] 16 is a flowchart showing the procedure of the current suppression control process executed by the battery ECU 90. This process is repeatedly executed by the battery ECU 90 at a predetermined control period, for example.

[0117] In step S231, it is determined whether or not the discharge power Wbdis1 of the first storage battery 31 is higher than the first discharge power threshold Wdisth1. The discharge power Wbdis1 of the first storage battery 31 may be calculated based on, for example, the detection value of the first current sensor 81A and the detection value of the first voltage sensor 85A. The first discharge power threshold Wdisth1 is set to, for example, a power value that does not exceed the maximum discharge power permitted by the first storage battery 31 (for example, the maximum rated power of the discharge side of the first storage battery 31). If it is determined that Wbdis1>Wdisth1, the process proceeds to step S232. On the other hand, if it is determined that Wbdis1≦Wdisth1, the process proceeds to step S233.

[0118] In step S232, the above-mentioned process B1 is executed as the protection process by the battery ECU 90. After that, the process proceeds to step S233.

[0119] In step S233, it is determined whether or not the discharge power Wbdis2 of the second storage battery 32 is higher than the second discharge power threshold Wdisth2. The discharge power Wbdis2 of the second storage battery 32 may be calculated based on, for example, the detection value of the second current sensor 81B and the detection value of the second voltage sensor 85B. The second discharge power threshold Wdisth2 is set to, for example, a power value that does not exceed the maximum discharge power permitted by the second storage battery 32 (for example, the maximum rated power of the discharge side of the second storage battery 32). If it is determined that Wbdis2>Wdisth2, the process proceeds to step S234. On the other hand, if it is determined that Wbdis2≦Wdisth2, the process ends.

[0120] In step S234, the above-mentioned process B3 is executed as the protection process by the battery ECU 90. Then, the process ends.

[0121] According to the present embodiment described above, it is possible to achieve the same effects as those of the fourth embodiment.

[0122] Sixth Embodiment The sixth embodiment will be described below with reference to the drawings, focusing on the differences from the fourth embodiment. In this embodiment, temperature is used instead of current in the current suppression control. The current suppression control of this embodiment will be described below with reference to FIGS. 17 and 18.

[0123] 17 is a flowchart showing the procedure of the current suppression control process executed by the motor ECU 100. This process is repeatedly executed by the motor ECU 100 at a predetermined control period, for example.

[0124] In step S241, it is determined whether the inverter temperature detection value Tid is higher than the inverter temperature threshold value Tith. If it is determined that Tid>Tith, the process proceeds to step S243. On the other hand, if it is determined that Tid≦Tith, the process proceeds to step S242.

[0125] In step S242, it is determined whether or not a notification regarding current suppression has been received from the battery ECU 90. If a notification has been received, the process proceeds to step S243. If no notification has been received, the process ends.

[0126] In step S243, at least one of the above-mentioned processes M1 and M2 is executed as a protection process by the motor ECU 100. Then, the process ends.

[0127] 18 is a flowchart showing the procedure of the current suppression control process executed by the battery ECU 90. This process is repeatedly executed by the battery ECU 90 at a predetermined control period, for example.

[0128] In step S251, it is determined whether the first temperature detection value Tbd1 is higher than the first temperature threshold value Tbth1. If it is determined that Tbd1>Tbth1, the process proceeds to step S252. On the other hand, if it is determined that Tbd1≦Tbth1, the process proceeds to step S253.

[0129] In step S252, the above-mentioned process B1 is executed as the protection process by the battery ECU 90. After that, the process proceeds to step S253.

[0130] In step S253, it is determined whether the second temperature detection value Tbd2 is higher than the second temperature threshold value Tbth2. If it is determined that Tbd2>Tbth2, the process proceeds to step S254. On the other hand, if it is determined that Tbd2≦Tbth2, the process ends.

[0131] In step S254, the above-mentioned process B3 is executed as the protection process by the battery ECU 90. Then, the process ends.

[0132] According to the present embodiment described above, it is possible to protect the components of the power conversion device and the storage battery from overcurrent.

[0133] Seventh embodiment The seventh embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, as shown in FIG. 19, the connection path 73 electrically connects the neutral point O of the armature winding 11 and the negative terminal of the first storage battery 31. The bypass switch 61 connects the positive terminal of the second storage battery 32 and the high potential side path 22H. The first end of the neutral point capacitor 75 is connected to a 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 high potential side path 22H.

[0134] In this embodiment, the terminal voltage (for example, rated voltage) of the first storage battery 31 is lower than the terminal voltage (for example, rated voltage) of the second storage battery 32.

[0135] Next, the external charging control of this embodiment will be described. Fig. 20 shows the control state of each switch during external charging control using the low-voltage charger 210. When the EVECU 110 determines that the external charger connected to the power conversion device is the low-voltage charger 210, it notifies the battery ECU 90 and the motor ECU 100 of the execution of charging by the low-voltage charger 210, thereby turning off the pre-charge main switch SMRP and the inter-battery switch 50, and turning on the high potential side main switch SMRH, the low potential side main switch SMRL, the bypass switch 61, the first motor side switch 71, and the second motor side switch 72. This causes the second storage battery 32 to be charged.

[0136] In the external charging control by the low-voltage charger 210, the motor ECU 100 performs switching control to alternately turn on upper and lower arm switches (corresponding to "target switches") of at least one phase, or performs switching control of a lower arm switch (corresponding to "target switches") of at least one phase with the upper arm switches SUH, SVH, SWH of all phases of the inverter 20 turned off, thereby stepping down the output voltage of the low-voltage charger 210 and supplying it to the first storage battery 31. In detail, the motor ECU 100 performs step-down control, which is the above-mentioned switching control for controlling the neutral point capacitor voltage VN to the target charging voltage. As a result, the first storage battery 31 is charged. Since the terminal voltage of the first storage battery 31 is lower than the terminal voltage of the second storage battery 32, the target charging voltage of the first storage battery 31 is lower than the target charging voltage of the second storage battery 32.

[0137] Next, the external power supply control of this embodiment will be described. Fig. 21 shows the control state of each switch during external power supply control in which power is supplied from the first and second storage batteries 31 and 32 to the low-voltage power supply target unit 230. When the EVECU 110 determines that the power supply target unit connected to the power conversion device is the low-voltage power supply target unit 230, it notifies the battery ECU 90 and the motor ECU 100 of the execution of low-voltage power supply control, thereby turning off the pre-charge main switch SMRP and the inter-battery switch 50, and turning on the high-potential side main switch SMRH, the low-potential side main switch SMRL, the bypass switch 61, the first motor side switch 71, and the second motor side switch 72. As a result, power is supplied from the second storage battery 32 to the low-voltage power supply target unit 230.

[0138] In the external power supply control for the low-voltage power supply target portion 230, the motor ECU 100 performs switching control for alternately turning on upper and lower arm switches (corresponding to "target switches") of at least one phase, or performs switching control for an upper arm switch (corresponding to "target switches") of at least one phase in a state in which the lower arm switches SUL, SVL, SWL of all phases of the inverter 20 are turned off, thereby boosting the output voltage of the first storage battery 31 and supplying it to the low-voltage power supply target portion 230. In detail, the motor ECU 100 performs boost control, which is the above-mentioned switching control for controlling the power supply voltage VB to the target power supply voltage. As a result, power is supplied from the first storage battery 31 to the low-voltage power supply target portion 230.

[0139] In the external charging / power supply control of this embodiment, similarly to the first to sixth embodiments, the processes shown in Figures 4 to 10 and 13 to 18 can be applied. In this case, the processes executed by the battery ECU 90 shown in Figures 5, 8, 10, 14, 16, and 18 can be executed by replacing the subscripts "1" and "2" attached to the parameters and the corresponding threshold values ​​in steps S111, S113, S141, S143, S161, S163, S211, S213, S231, S233, S251, and S253.

[0140] In process M1 during execution of external charging control, the duty ratio Duty of the lower arm switch is reduced, not the upper arm switch. Also, in process M1 during execution of external power supply control, the duty ratio Duty of the upper arm switch is reduced, not the lower arm switch. By the current suppression control during external charging control in this embodiment, the charging power of the first storage battery 31 may be reduced to be equal to or less than the maximum charging power of the first storage battery 31.

[0141] As an example, Fig. 22 illustrates a flowchart of a current suppression control process using the current during external charging control as a parameter, similar to Fig. 5. This process is repeatedly executed by the battery ECU 90, for example, at a predetermined control period.

[0142] In step S301, it is determined whether the second current detection value Ibd2 is higher than the second charging current threshold Ichrth2. If it is determined that Ibd2>Ichrth2, the process proceeds to step S302. On the other hand, if it is determined that Ibd2≦Ichrth2, the process proceeds to step S303. In step S301, the subscript "1" of the parameter "Ibd1" and the corresponding threshold "Ichrth1" in step S111 are replaced with "2".

[0143] In step S302, at least one of the above-mentioned processes B1 and B2 is executed as a protection process by the battery ECU 90. The storage battery having the higher inter-terminal voltage is the second storage battery 32. Therefore, the process B2 may be, for example, a process to notify the EVECU 110 that the current flowing through the second storage battery 32 needs to be suppressed. Then, the process proceeds to step S303.

[0144] In step S303, it is determined whether the first current detection value Ibd1 is higher than the first charging current threshold Ichrth1. If it is determined that Ibd1>Ichrth1, the process proceeds to step S304. If it is determined that Ibd1≦Ichrth1, the process ends. In step S303, the subscript "2" of the parameter "Ibd2" and the corresponding threshold "Ichrth2" in step S113 are replaced with "1".

[0145] In step S304, at least one of the above-mentioned processes B3 and B4 is executed as a protection process by the battery ECU 90. The process B4 is a process for notifying the EVECU 110 that it is necessary to suppress the current flowing through the first storage battery 31. Then, the process ends.

[0146] According to the present embodiment described above, it is possible to achieve the same effects as the first to sixth embodiments.

[0147] <Other embodiments> Each of the above embodiments may be modified as follows.

[0148] In the process shown in FIG. 9 of the third embodiment and the process shown in FIG. 17 of the sixth embodiment, the detection value of a temperature sensor that detects the temperature of the armature winding may be used instead of the temperature of the inverter 20.

[0149] In process M1 of each of the above embodiments, the amount of decrease in the duty ratio Duty may be increased as the parameter (phase current detection value Ipd, phase power value Wpd, or inverter temperature detection value Tid) compared with the threshold value increases.

[0150] The threshold values ​​used in the current suppression control in each of the above embodiments may be set taking into account communication delays and control delays between the ECUs.

[0151] In each of the above embodiments, the power conversion device does not necessarily have to include either the first or second motor-side switch 71, 72. In addition, the power conversion device does not necessarily have to include both the first and second motor-side switches 71, 72.

[0152] The switches of the inverter 20 are not limited to IGBTs, but may be, for example, MOSFETs equipped with body diodes. When the switches of the inverter 20 are N-channel MOSFETs, the high-potential terminal becomes the drain and the low-potential terminal becomes the source. When the switches of the inverter 20 are P-channel MOSFETs, the high-potential terminal becomes the source and the low-potential terminal becomes the drain.

[0153] The high potential side main switch SMRH does not have to be provided.

[0154] Instead of the low potential side main switch SMRL, a series connection of the pre-charge main switch SMRP and the pre-charge resistor 40 may be connected in parallel to the high potential side main switch SMRH. In this case, the low potential side main switch SMRL does not have to be provided.

[0155] The fuses 41 and 42 do not necessarily have to be provided.

[0156] The motor is not limited to a star-connected one, and may be a delta-connected one. The motor and inverter are not limited to a three-phase one, and may be a two-phase one, or a four-phase or more phase one. The motor is not limited to a permanent magnet-type synchronous machine having a permanent magnet as a field pole on the rotor, and may be a wound field-type synchronous machine having a field winding as a field pole on the rotor. In this case, the rotor may be provided with both a field winding and a permanent magnet. The motor is not limited to a synchronous machine, and may be an induction machine.

[0157] The battery ECU 90 and the motor ECU 100 may be able to exchange information via the EVECU 110 .

[0158] The control device that performs external charging, power supply control, and equalization control is not limited to the motor ECU 100. For example, each control may be performed by a plurality of control devices, such as the battery ECU 90, the EVECU 110, and the motor ECU 100, working together.

[0159] The power storage unit to be charged by the external charger is not limited to a storage battery. For example, it may be a large-capacity electric double-layer capacitor, or may be one that includes both a storage battery and an electric double-layer capacitor.

[0160] The moving body on which the power conversion device is mounted is not limited to a vehicle, but may be, for example, an aircraft or a ship. The power conversion device is not limited to a moving body, but may be a stationary device.

[0161] The control device and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control device and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control device and the method described in the present disclosure may be realized by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. In addition, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer. [Explanation of symbols]

[0162] 10...motor, 11U, 11V, 11W...armature winding, 20...inverter, 22H...high potential side path, 22L...low potential side path, 31, 32...first and second storage batteries, 50...inter-battery switch, 60...bypass switch, 73...connection path, 90...battery ECU, 100...motor ECU, 110...EVECU.

Claims

1. An inverter (20) having upper and lower arm switches (SUH to SWL) for multiple phases; a motor (10) having an armature winding (11U to 11W) electrically connected to a low potential side terminal of the upper arm switch of each phase and a high potential side terminal of the lower arm switch of each phase; A power conversion device comprising: a high potential side path (22H) electrically connecting a positive terminal of the first storage unit (31) and a high potential side terminal of the upper arm switch; a low potential side path (22L) electrically connecting a negative terminal of the second storage unit (32) and a low potential side terminal of the lower arm switch; an inter-storage unit switch (50) that, when turned on, electrically connects the negative electrode terminal of the first storage unit and the positive electrode terminal of the second storage unit, and, when turned off, electrically disconnects the negative electrode terminal of the first storage unit and the positive electrode terminal of the second storage unit; a bypass switch (60, 61) that electrically connects negative electrode terminals of the first power storage unit and the second power storage unit to each other and electrically connects positive electrode terminals of the first power storage unit and the second power storage unit to each other; a connection path (73) electrically connecting the negative terminal of the first storage unit or the positive terminal of the second storage unit to the armature winding; a control device (90, 100, 110) that performs current flow control, which is switching control of a target switch that is at least one of the upper and lower arm switches, in order to flow a current through the connection path; Equipped with The control device performs current suppression control to suppress a current flowing through a closed circuit including the connection path to a maximum current of the power conversion device during execution of the current flow control.

2. the bypass switch (60) electrically connects the negative electrode terminal of the first power storage unit and the negative electrode terminal of the second power storage unit when turned on, and electrically disconnects the negative electrode terminal of the first power storage unit and the negative electrode terminal of the second power storage unit when turned off; The power conversion device according to claim 1 , wherein the connection path electrically connects the armature winding and a positive terminal of the second power storage unit.

3. The control device includes:

3. The power conversion device according to claim 2, wherein, when an external charger (210) is electrically connected to the high potential side path and the low potential side path, the current flow control comprises performing switching control of the upper arm switch, which is the target switch, in a state in which the inter-storage unit switch is turned off and the bypass switch is turned on, thereby performing external charging control in which a current flows through a closed circuit including the external charger, the inverter, the armature winding, the connection path, the bypass switch, and the second storage unit, thereby charging the second storage unit.

4. The control device includes: During execution of the external charging control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the second power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the second power storage unit; Get one of the parameters, The power conversion device according to claim 3 , wherein, when the acquired parameter exceeds a threshold value, control is performed to reduce a duty ratio of the upper arm switch as the current suppression control.

5. The high potential side path is electrically connected to a high potential side terminal of the upper arm switch, the low potential side path is electrically connected to a low potential side terminal of the lower arm switch, A motor-side switch (72) provided in the connection path; main switches (SMRH, SMRL) electrically connecting the high potential side path and the low potential side path to the first power storage unit and the second power storage unit; Equipped with The control device includes: During execution of the external charging control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the second power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the second power storage unit; Get one of the parameters, The power conversion device according to claim 3 , wherein, when the acquired parameter exceeds a threshold value, the current suppression control is performed by turning off at least one of the motor-side switch and the main switch.

6. The control device includes: During execution of the external charging control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the second power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the second power storage unit; Get one of the parameters, The power conversion device according to claim 3 , wherein, when the acquired parameter exceeds a threshold value, control is performed to reduce the output power of the external charger as the current suppression control.

7. The power conversion device according to any one of claims 4 to 6, wherein the control device performs the current suppression control to keep the charging power of the second power storage unit equal to or less than a maximum charging power of the second power storage unit.

8. The control device includes:

3. The power conversion device according to claim 2, wherein, when an external power supply target part (230) is electrically connected to the high potential side path and the low potential side path, the current flow control is performed by performing switching control of the lower arm switch, which is the target switch, in a state in which the inter-storage unit switch is turned off and the bypass switch is turned on, thereby performing external power supply control to supply a current to the external power supply target part via a closed circuit including the external power supply target part, the first power storage unit, the connection path, the armature winding, and the inverter.

9. The control device includes: During execution of the external power supply control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the first power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the second power storage unit; Get one of the parameters, The power conversion device according to claim 8 , wherein, when the acquired parameter exceeds a threshold value, control is performed to reduce a duty ratio of the lower arm switch as the current suppression control.

10. The high potential side path is electrically connected to a high potential side terminal of the upper arm switch, the low potential side path is electrically connected to a low potential side terminal of the lower arm switch, A motor-side switch (72) provided in the connection path; main switches (SMRH, SMRL) electrically connecting the high potential side path and the low potential side path to the first power storage unit and the second power storage unit; Equipped with The control device includes: During execution of the external power supply control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the second power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the second power storage unit; Get one of the parameters, The power conversion device according to claim 8 , wherein, when the acquired parameter exceeds a threshold value, the current suppression control is performed by turning off at least one of the motor-side switch and the main switch.

11. the bypass switch (61) electrically connects the positive electrode terminal of the first power storage unit and the positive electrode terminal of the second power storage unit when turned on, and electrically disconnects the positive electrode terminal of the first power storage unit and the positive electrode terminal of the second power storage unit when turned off; The power conversion device according to claim 1 , wherein the connection path electrically connects the armature winding and a negative electrode terminal of the first power storage unit.

12. The control device includes:

12. The power conversion device according to claim 11, wherein, when an external charger (210) is electrically connected to the high potential side path and the low potential side path, the current flow control comprises performing switching control of the lower arm switch, which is the target switch, in a state in which the inter-storage unit switch is turned off and the bypass switch is turned on, thereby performing external charging control to charge the first storage unit by causing a current to flow through a closed circuit including the external charger, the first storage unit, the connection path, the armature winding, and the inverter.

13. The control device includes: During execution of the external charging control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the first power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the second power storage unit; Get one of the parameters, The power conversion device according to claim 12 , wherein, when the acquired parameter exceeds a threshold value, control is performed to reduce a duty ratio of the lower arm switch as the current suppression control.

14. The high potential side path is electrically connected to a high potential side terminal of the upper arm switch, the low potential side path is electrically connected to a low potential side terminal of the lower arm switch, A motor-side switch (72) provided in the connection path; main switches (SMRH, SMRL) electrically connecting the high potential side path and the low potential side path to the first power storage unit and the second power storage unit; Equipped with The control device includes: During execution of the external charging control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the first power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the second power storage unit; Get one of the parameters, The power conversion device according to claim 12 , wherein, when the acquired parameter exceeds a threshold value, the current suppression control is performed by turning off at least one of the motor-side switch and the main switch.

15. The control device includes: During execution of the external charging control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the first power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the second power storage unit; Get one of the parameters, The power conversion device according to claim 12 , wherein, when the acquired parameter exceeds a threshold value, control for reducing an output power of the external charger is performed as the current suppression control.

16. The power conversion device according to any one of claims 13 to 15, wherein the control device performs the current suppression control to keep the charging power of the first power storage unit equal to or less than a maximum charging power of the first power storage unit.

17. The control device includes:

13. The power conversion device according to claim 12, wherein, when an external power supply target part (230) is electrically connected to the high potential side path and the low potential side path, the current flow control is performed by performing switching control of the upper arm switch, which is the target switch, in a state where the inter-storage unit switch is turned off and the bypass switch is turned on, thereby performing external power supply control to supply a current to the external power supply target part via a closed circuit including the external power supply target part, the first power storage unit, the connection path, the armature winding, and the inverter.

18. The control device includes: During execution of the external power supply control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the first power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the second power storage unit; Get one of the parameters, The power conversion device according to claim 17 , wherein, when the acquired parameter exceeds a threshold value, control is performed to reduce a duty ratio of the upper arm switch as the current suppression control.

19. The high potential side path is electrically connected to a high potential side terminal of the upper arm switch, the low potential side path is electrically connected to a low potential side terminal of the lower arm switch, A motor-side switch (72) provided in the connection path; main switches (SMRH, SMRL) electrically connecting the high potential side path and the low potential side path to the first power storage unit and the second power storage unit; Equipped with The control device includes: During execution of the external power supply control, an electrical parameter being a current or a power transmitted through at least one of the inverter, the armature winding, and the second power storage unit; a temperature parameter being a temperature of at least one of the inverter, the armature winding, and the first power storage unit; Get one of the parameters, The power conversion device according to claim 18 , wherein, when the acquired parameter exceeds a threshold value, control is performed to turn off at least one of the motor-side switch and the main switch as the current suppression control.

20. The power conversion device according to claim 4 , 9 , 13 , or 18 , wherein the control device increases the amount of decrease in the duty ratio as the acquired parameter increases.

21. An inverter (20) having upper and lower arm switches (SUH to SWL) for multiple phases; a motor (10) having an armature winding (11U to 11W) electrically connected to a low potential side terminal of the upper arm switch of each phase and a high potential side terminal of the lower arm switch of each phase; A program applied to a power conversion device comprising: The power conversion device is a high potential side path (22H) electrically connecting a positive terminal of the first storage unit (31) and a high potential side terminal of the upper arm switch; a low potential side path (22L) electrically connecting a negative terminal of the second storage unit (32) and a low potential side terminal of the lower arm switch; an inter-storage unit switch (50) that, when turned on, electrically connects the negative electrode terminal of the first storage unit and the positive electrode terminal of the second storage unit, and, when turned off, electrically disconnects the negative electrode terminal of the first storage unit and the positive electrode terminal of the second storage unit; a bypass switch (60, 61) that electrically connects negative electrode terminals of the first power storage unit and the second power storage unit to each other and electrically connects positive electrode terminals of the first power storage unit and the second power storage unit to each other; a connection path (73) electrically connecting the negative terminal of the first storage unit or the positive terminal of the second storage unit to the armature winding; Equipped with To the computer (91, 101, 111), a process of performing a current flow control, which is a switching control of a target switch that is at least one of the upper and lower arm switches, in order to flow a current through the connection path; a process of controlling a current flowing through a closed circuit including the connection path during execution of the current flow control to be equal to or less than a maximum current of the power conversion device; A program to execute.

Images