Power conversion module and power conversion device

Abstract

To provide a power conversion device and a drive system, which can reduce installation space of a bus bar.SOLUTION: A power conversion module 20 includes circuit units 201 and 202 and a sensor device 130. The circuit unit 201 includes semiconductor elements 61H and 61L and an O terminal 115. The circuit unit 202 includes semiconductor elements 62H and 62L, an O terminal 116 and a change-over switch 80. The sensor device 130 is provided in the O terminal 116 but is not provided in the O terminal 115. The sensor device 130 includes sensor elements 131 and 132, and a sensor bus bar 140. The sensor elements 131 and 132 detect current flowing in the sensor bus bar 140. The sensor bus bar 140 is electrically connected to the O terminal 116.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] TECHNICAL FIELD The disclosure herein relates to power conversion modules and power conversion devices. [Background technology]

[0002] Patent Document 1 discloses a power conversion device including a first inverter connected to one end of a winding of a rotating electric machine and a second inverter connected to the other end of the winding. In this power conversion device, a current flowing through the winding is detected by a current sensor. The contents of the prior art document are incorporated by reference as an explanation of the technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-177342 Summary of the Invention [Problem to be solved by the invention]

[0004] In a power conversion device, a bus bar forms a path connecting the first inverter and the second inverter to the windings, and a current sensor may be provided on the bus bar. In this configuration, there is a concern that the bus bar installation space will increase by the amount of the current sensor provided on the bus bar. In terms of the above and other aspects not mentioned, further improvements are required in power conversion modules.

[0005] One disclosed object is to provide a power conversion device and a drive system that can reduce the installation space of the bus bar. [Means for solving the problem]

[0006] One aspect of the disclosure is A power conversion module (20) that converts power supplied to a rotating electric machine (3), a first semiconductor element (61H, 61L) constituting a first inverter (8) connected to one end of a winding of the rotating electric machine via a first path (13); second semiconductor elements (62H, 62L) constituting a second inverter (9) connected to the other end of the winding via a second path (14); a first bus bar (115) arranged in a predetermined direction (X), electrically connected to the first semiconductor element so as to form a part of the first path, and for connecting one end of the first inverter; a second bus bar (116, 140) arranged in a predetermined direction, electrically connected to the second semiconductor element so as to form a part of the second path, and for connecting the second inverter to the other end; a current detection unit (131, 132) provided on a target bus bar (116, 140; 115) that is one of the first bus bar and the second bus bar, and that detects a current flowing through the target bus bar; Equipped with The other of the first bus bar and the second bus bar is a power conversion module, which is a non-target bus bar (115; 116) that is not provided with a current detection unit.

[0007] According to the power conversion module, in a configuration in which a plurality of target busbars and a plurality of non-target busbars are arranged in a predetermined direction, the target busbars are provided with current detection units, while the non-target busbars are not provided with current detection units. In this configuration, the distance between two adjacent non-target busbars in the predetermined direction can be minimized by the amount corresponding to the absence of current detection units in the non-target busbars. This allows the installation space required for installing the plurality of non-target busbars in the predetermined direction to be reduced.

[0008] One aspect of the disclosure is A power conversion device (18) including a power conversion module (20) for converting power supplied to a rotating electric machine (3) by the power conversion module, The power conversion module is a first semiconductor element (61H, 61L) constituting a first inverter (8) connected to one end of a winding of the rotating electric machine via a first path (13); second semiconductor elements (62H, 62L) constituting a second inverter (9) connected to the other end of the winding via a second path (14); a first bus bar (115) arranged in a predetermined direction (X), electrically connected to the first semiconductor element so as to form a part of the first path, and for connecting one end of the first inverter; a second bus bar (116, 140) arranged in a predetermined direction, electrically connected to the second semiconductor element so as to form a part of the second path, and for connecting the second inverter to the other end; It has moreover, a current detection unit (131, 132) provided on a target bus bar (116, 140) that is one of the first bus bar and the second bus bar, and configured to detect a current flowing through the target bus bar; The other of the first bus bar and the second bus bar is a non-target bus bar (115) that is not provided with a current detection unit, and is a power converter.

[0009] According to the power conversion device, similarly to the power conversion module, it is possible to reduce the installation space of the non-target busbars in a predetermined direction.

[0010] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims and in this section are intended to exemplify correspondences with the following embodiments and are not intended to limit the technical scope. The objectives, features, and advantages disclosed in this specification will become more apparent by reference to the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a power conversion circuit and a drive system according to a first embodiment. [Figure 2] FIG. 4 is a diagram showing an example of an operating point map of the rotating electric machine. [Figure 3] FIG. 1 is a diagram showing a star-connected drive. [Figure 4] FIG. 10 is a diagram showing an open connection drive. [Figure 5] FIG. 2 is a circuit diagram showing a state in which an external device is connected. [Figure 6] 1 is a diagram showing a connection structure between a power conversion module and an external device. FIG. [Figure 7] FIG. 2 is a plan view showing the power conversion module. [Figure 8] FIG. 2 is a plan view showing the internal structure of the power conversion module. [Figure 9] FIG. 8 is a cross-sectional view taken along line IX-IX in FIG. 7. [Figure 10] FIG. 8 is a cross-sectional view taken along line XX in FIG. [Figure 11] FIG. 2 is a schematic vertical cross-sectional view of the sensor device. [Figure 12] 10 is a flowchart showing the procedure of a rotation control process. [Figure 13] FIG. 10 is a diagram illustrating a reference example. [Figure 14] FIG. 10 is a diagram illustrating a reference example. [Figure 15] FIG. 10 is a diagram illustrating a power conversion circuit and a drive system according to a modified example. [Figure 16] FIG. 10 is a diagram illustrating a power conversion circuit and a drive system according to a modified example. [Figure 17] FIG. 10 is a diagram illustrating a power conversion circuit and a drive system according to a modified example. [Figure 18] FIG. 10 is a diagram illustrating a power conversion circuit and a drive system according to a second embodiment. [Figure 19] FIG. 2 is a plan view showing the internal structure of the power conversion module. [Figure 20] FIG. 10 is a diagram illustrating a power conversion circuit and a drive system according to a third embodiment. [Figure 21] FIG. 2 is a plan view showing the internal structure of the power conversion module. [Figure 22] FIG. 10 is a diagram illustrating a power conversion circuit and a drive system according to a fourth embodiment. [Figure 23] FIG. 2 is a plan view showing the internal structure of the power conversion module. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments will be described with reference to the drawings. Note that in each embodiment, corresponding components are designated by the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment previously described may be applied to the remaining portion of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments may be partially combined together even if not explicitly stated, provided that there is no particular problem with the combination.

[0013] The power conversion module of this embodiment is applied to, for example, a mobile body using a rotating electric machine as a drive source, such as an electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an aircraft such as an electric vertical take-off and landing aircraft or a drone, a ship, a construction machine, an agricultural machine, etc.

[0014] (First embodiment) First, the schematic configuration of a drive system for a moving body will be described with reference to FIG.

[0015] <Drive systems for moving objects> As shown in FIG. 1, a drive system 1 for a moving body includes a DC power supply 2, a rotating electric machine 3, and a power conversion circuit 4.

[0016] The DC power supply 2 may be, for example, a rechargeable secondary battery such as a lithium ion battery or a nickel-metal hydride battery. The DC power supply 2 may also be one that converts AC power to DC and outputs it. The DC power supply 2 supplies power to the rotating electrical machine 3. The DC power supply 2 corresponds to a power supply unit.

[0017] The rotating electric machine 3 is a three-phase open-winding type rotating electric machine with an open neutral point. The rotating electric machine 3 has a U-phase winding 3U, a V-phase winding 3V, and a W-phase winding 3W. Hereinafter, the U-phase winding 3U, the V-phase winding 3V, and the W-phase winding 3W may be simply referred to as windings 3U, 3V, and 3W.

[0018] The rotating electric machine 3 functions, for example, as a drive source for a moving body, that is, as an electric motor. If the moving body is a vehicle, the rotating electric machine 3 generates torque for driving drive wheels (not shown). The rotating electric machine 3 is not limited to an electric motor. The rotating electric machine 3 may be a motor generator that functions as both an electric motor and a generator, or may be a generator.

[0019] The power conversion circuit 4 converts power between the DC power supply 2 and the rotating electric machine 3. The drive system 1 is a common power supply system in which a common DC power supply 2 supplies power to two inverters 8 and 9 (described later) to drive the rotating electric machine 3. The drive system 1 may include only one common DC power supply 2 as shown in FIG. 1, or multiple common DC power supplies 2. The drive system 1 may include a power supply switch (not shown), such as an SMR, between the DC power supply 2 and the power conversion circuit 4. SMR is an abbreviation for System Main Relay. Turning the power supply switch on enables power supply from the DC power supply 2 to the rotating electric machine 3, and turning the power supply switch off cuts off the power supply from the DC power supply 2 to the rotating electric machine 3.

[0020] <Power conversion circuit> Next, the power conversion circuit 4 will be described with reference to Fig. 1. Fig. 1 shows an example of the power conversion circuit 4. The power conversion circuit 4 shown in Fig. 1 includes power lines 5 and 6, a smoothing capacitor 7, inverters 8 and 9, a changeover switch 10, and snubber circuits 11 and 12.

[0021] The power supply line 5 is a high-potential power line. The power supply line 5 is connected to the positive electrode of the DC power supply 2. The power supply line 5 may be referred to as a positive power supply line, P line, etc. The power supply line 6 is a low-potential power line. The power supply line 6 is connected to the negative electrode of the DC power supply 2. The power supply line 6 may be referred to as a negative power supply line, N line, etc. The power supply lines 5 and 6 are configured to include bus bars that are, for example, metal plates.

[0022] The power supply line 5 has wires 5A1 and 5A2. The wires 5A1 and 5A2 are part of the wires that make up the power supply line 5. The wires 5A1 and 5A2 are wires that connect the inverter 8 and the inverter 9 in the power supply line 5. The wire 5A1 is wire that connects the inverter 8 and the changeover switch 10 in the power supply line 5. The wire 5A2 is wire that connects the changeover switch 10 and the inverter 9 in the power supply line 5.

[0023] The smoothing capacitor 7 mainly smoothes the DC voltage supplied from the DC power supply 2. The smoothing capacitor 7 is provided between the power supply lines 5 and 6. The positive electrode of the smoothing capacitor 7 is connected to the power supply line 5 between the DC power supply 2 and the inverters 8 and 9. The negative electrode of the smoothing capacitor 7 is connected to the power supply line 6 between the DC power supply 2 and the inverters 8 and 9. The smoothing capacitor 7 is connected in parallel to the inverters 8 and 9.

[0024] The inverters 8 and 9 are DC-AC conversion circuits. The inverters 8 and 9 are three-phase inverter circuits. The inverter 8 corresponds to a first inverter, and the inverter 9 corresponds to a second inverter. The inverter 8 is configured with upper and lower arm circuits 8HL for three phases. The upper and lower arm circuits 8HL are sometimes referred to as legs. The upper and lower arm circuit 8HL has an upper arm 8H and a lower arm 8L. The upper arm 8H and the lower arm 8L are connected in series between the power supply lines 5 and 6, with the upper arm 8H on the power supply line 5 side.

[0025] The connection point between the upper arm 8H and the lower arm 8L is connected to the winding of the corresponding phase in the rotating electric machine 3 via an output line 13. The inverter 8 has six arms. Each arm is configured with a switching element. The number of switching elements configuring each arm is not particularly limited. There may be one or more. When there are more than one switching elements, the multiple switching elements connected in parallel to each other are turned on and off at the same timing by a common gate drive signal (drive voltage).

[0026] In the example shown in FIG. 1, an n-channel MOSFET 8S is used as the switching element constituting each arm. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. In the upper arm 8H, the drain terminal of the MOSFET 8S is connected to the power supply line 5. In the lower arm 8L, the source terminal of the MOSFET 8S is connected to the power supply line 6. The source terminal of the MOSFET 8S in the upper arm 8H and the drain terminal of the MOSFET 8S in the lower arm 8L are connected to each other.

[0027] A freewheeling diode 8D is connected in antiparallel to each MOSFET 8S. The diode 8D may be a parasitic diode (body diode) of the MOSFET 8S, or may be provided separately from the parasitic diode. The anode terminal of the diode 8D is connected to the source terminal of the corresponding MOSFET 8S, and the cathode terminal is connected to the drain terminal.

[0028] The inverter 9 has the same configuration as the inverter 8. The inverter 9 is configured with upper and lower arm circuits 9HL for three phases. The upper and lower arm circuit 9HL has an upper arm 9H and a lower arm 9L. The upper arm 9H and the lower arm 9L are connected in series between the power supply lines 5 and 6, with the upper arm 9H on the power supply line 5 side.

[0029] The connection point between the upper arm 9H and the lower arm 9L is connected to the winding of the corresponding phase in the rotating electric machine 3 via an output line 14. The inverter 9 also has six arms. Each arm is configured with a switching element. The number of switching elements constituting each arm is not particularly limited. It may be one or more.

[0030] In the example shown in Fig. 1, an n-channel MOSFET 9S is used as the switching element constituting each arm. In the upper arm 9H, the drain terminal of the MOSFET 9S is connected to the power supply line 5. In the lower arm 9L, the source terminal of the MOSFET 9S is connected to the power supply line 6. The source terminal of the MOSFET 9S in the upper arm 9H and the drain terminal of the MOSFET 9S in the lower arm 9L are connected to each other. A freewheeling diode 9D is connected in anti-parallel to each MOSFET 9S.

[0031] As described above, the high-potential terminals (drain terminals) of the upper arms 8H, 9H of the inverters 8, 9 are connected to the power line 5. The low-potential terminals (source terminals) of the lower arms 8L, 9L are connected to the power line 6. A node connecting the upper arm 8H and the lower arm 8L is connected to one end of the corresponding phase winding via an output line 13, and a node connecting the upper arm 9H and the lower arm 9L is connected to the other end of the corresponding phase winding via an output line 14. Specifically, one end of the U-phase winding 3U is connected to a node U1 of the U-phase upper and lower arm circuit 8HL, and the other end of the U-phase winding 3U is connected to a node U2 of the U-phase upper and lower arm circuit 9HL. One end of the V-phase winding 3V is connected to a node V1 of the V-phase upper and lower arm circuit 8HL, and the other end of the V-phase winding 3V is connected to a node V2 of the V-phase upper and lower arm circuit 9HL. One end of the W-phase winding 3W is connected to a node W1 of a W-phase upper and lower arm circuit 8HL, and the other end of the W-phase winding 3W is connected to a node W2 of a W-phase upper and lower arm circuit 9HL.

[0032] The switching elements constituting the inverters 8 and 9 are not limited to the above-mentioned MOSFETs. For example, IGBTs may be used. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. In the case of an IGBT, a freewheeling diode is also connected in antiparallel. The types of switching elements constituting the inverters 8 and 9 may be the same or different. For example, one of the inverters 8 and 9 may be composed of a MOSFET and the other of an IGBT. The types (materials) of the semiconductor substrates may be different.

[0033] The changeover switch 10 is a semiconductor switch. A semiconductor switch has a switching element formed on a semiconductor chip. The switching element is not particularly limited and may have the same configuration as or a different configuration from the switching element constituting at least one of the inverters 8, 9. The changeover switch 10 is provided between the inverters 8 and 9 on at least one of the power supply lines 5, 6. The changeover switch 10 is provided on the power supply line. When the changeover switch 10 is closed, it connects the high-potential side terminal of the upper arm 9H of the inverter 9 to the smoothing capacitor 7 (DC power supply 2). When the changeover switch 10 is open, it cuts off the connection between the high-potential side terminal of the upper arm 9H and the smoothing capacitor 7 (DC power supply 2). The changeover switch 10 may also be called a switch or an open / close switch.

[0034] The switching element of the changeover switch 10 illustrated in FIG. 1 is a MOSFET. A diode is connected in anti-parallel to the MOSFET. The diode is, for example, a parasitic diode. The drain terminal of the changeover switch 10 (MOSFET) is connected to the wiring 5A1, and the source terminal is connected to the wiring 5A2. When the MOSFET is turned on and the changeover switch 10 is closed, the high-potential side terminal of the upper arm 9H is electrically connected to the smoothing capacitor 7. When the MOSFET is turned off and the changeover switch 10 is opened, the electrical connection between the high-potential side terminal of the upper arm 9H and the smoothing capacitor 7 is interrupted.

[0035] Furthermore, in the power conversion circuit 4, a changeover switch 10 is provided for each phase of the upper and lower arm circuits 9HL. The power conversion circuit 4 includes three changeover switches 10. The drain terminal of each changeover switch 10 is connected to a wiring 5A1, and the source terminal is connected to a wiring 5A2. One of the changeover switches 10 is connected in series to the U-phase upper and lower arm circuit 9HL. The other changeover switch 10 is connected in series to the V-phase upper and lower arm circuit 9HL. The other changeover switch 10 is connected in series to the W-phase upper and lower arm circuit 9HL. The source terminals of the three changeover switches 10 are electrically connected to each other by a wiring 5A2. The source terminals of the three changeover switches 10 are commonly connected.

[0036] The snubber circuit 11 is connected in parallel to the inverter 9, i.e., the upper and lower arm circuits 9HL. The snubber circuit 11 reduces the inductance of the upper and lower arm circuits 9HL. In other words, the snubber circuit 11 absorbs a transient high voltage, or so-called switching surge, that occurs when the switching elements (MOSFETs 9S) that make up the upper and lower arm circuits 9HL are switched. This enables the inverter 9 to perform high-speed switching.

[0037] The snubber circuit 11 includes at least a capacitor 11C. The snubber circuit 11 may be, for example, a C snubber circuit including a capacitor, or an RC snubber circuit including a capacitor and a resistor. It may also be an RCD snubber circuit including a capacitor, a resistor, and a diode. The snubber circuit 11 shown in FIG. 1 is an RC snubber circuit in which a capacitor 11C and a resistor 11R are connected in series. One end of the snubber circuit 11 is connected to the power supply line 5. One end of the snubber circuit 11 is connected to a wiring 5A1 of the power supply line 5. The other end of the snubber circuit 11 is connected to the power supply line 6. The snubber circuit 11 is electrically connected to the smoothing capacitor 7 and the DC power supply 2 without passing through the selector switch 10.

[0038] In the power conversion circuit 4 illustrated in FIG. 1, a snubber circuit 11 is provided for each phase of the upper and lower arm circuits 9HL. The power conversion circuit 4 includes three snubber circuits 11 in addition to the above-described three changeover switches 10. One end of each snubber circuit 11 is connected to the wiring 5A1, and the other end is connected to the power supply line 6. Each snubber circuit 11 includes a capacitor 11C and a resistor 11R. One of the snubber circuits 11 is connected in parallel to the U-phase upper and lower arm circuit 9HL. The other snubber circuit 11 is connected in parallel to the V-phase upper and lower arm circuit 9HL. The other snubber circuit 11 is connected in parallel to the W-phase upper and lower arm circuit 9HL.

[0039] The snubber circuit 12 is connected in parallel to the inverter 8, i.e., the upper and lower arm circuits 8HL. The snubber circuit 12 reduces the inductance of the upper and lower arm circuits 8HL, thereby enabling high-speed switching of the inverter 8. The snubber circuit 12 includes at least a capacitor 12C. The snubber circuit 12 may be, for example, a C snubber circuit, an RC snubber circuit, or an RCD snubber circuit. The snubber circuit 12 shown in FIG. 1 is an RC snubber circuit in which a capacitor 12C and a resistor 12R are connected in series. One end of the snubber circuit 12 is connected to the power supply line 5. The other end of the snubber circuit 12 is connected to the power supply line 6.

[0040] In the power conversion circuit 4 illustrated in FIG. 1, a snubber circuit 12 is provided for each phase of the upper and lower arm circuits 8HL. The power conversion circuit 4 includes three snubber circuits 12. One end of each snubber circuit 12 is connected to the power supply line 5, and the other end is connected to the power supply line 6. Each snubber circuit 12 includes a capacitor 12C and a resistor 12R. One of the snubber circuits 12 is connected in parallel to the U-phase upper and lower arm circuit 8HL. The other snubber circuit 12 is connected in parallel to the V-phase upper and lower arm circuit 8HL. The other snubber circuit 12 is connected in parallel to the W-phase upper and lower arm circuit 8HL.

[0041] As illustrated in FIG. 1, the power conversion circuit 4 may include a control unit (CTR) 15. The control unit 15 may include, for example, a processor 15a, a memory 15b, and a storage 15c. The processor 15a accesses the memory 15b to execute various processes. The memory 15b is a rewritable volatile storage medium. The memory 15b is, for example, a RAM. RAM is an abbreviation for Random Access Memory. The storage 15c is a rewritable nonvolatile memory. The storage 15c may be realized by at least one type of non-transitory tangible storage medium, such as a semiconductor memory, a magnetic medium, or an optical medium. The storage 15c may include multiple types of storage media, such as a ROM and a flash memory. ROM is an abbreviation for Read Only Memory.

[0042] The storage 15c stores a program 15d executed by the processor 15a. The program 15d configures a plurality of functional units by causing the processor 15a to execute a plurality of instructions. The processing performed by the control unit 15 may be realized by software processing in which the processor 15a executes the program 15d described above, or may be realized by hardware processing using a dedicated electronic circuit. It may also be realized by a combination of software processing and hardware processing. The program 15d includes a program for executing a rotation control process, which will be described later.

[0043] The control unit 15 may have, for example, a drive command generation unit and a drive circuit unit (not shown). The drive command generation unit controls the inverters 8 and 9. The drive command generation unit generates drive commands (command signals) for controlling the on / off of the MOSFETs 8S and 9S and outputs them to the drive circuit unit. The drive command generation unit generates drive commands based on drive requests for the rotating electric machine 3, such as torque command values ​​input from a higher-level ECU (not shown), and signals detected by various sensors. The various sensors may include a current sensor, a rotation angle sensor, a voltage sensor, etc. The rotation angle sensor detects the rotation angle of the rotor of the rotating electric machine 3. The voltage sensor detects the voltage across the smoothing capacitor 7. Current sensors include current sensors 121 and 122, which will be described later.

[0044] The drive command generation unit controls the changeover switch 10. The drive command generation unit generates drive commands for controlling the on / off of the changeover switch 10 and outputs the drive commands to the drive circuit unit. The drive circuit unit is sometimes referred to as a driver. The drive circuit unit can independently control the on / off of the MOSFET 8S, the MOSFET 9S, and the changeover switch 10 based on the drive commands. For convenience, signal lines for transmitting drive signals from the control unit 15 to each switching element are omitted from FIG. 1.

[0045] <Star connection drive and open connection drive> Next, star connection driving and open connection driving will be described with reference to Figures 2, 3, and 4. Figure 2 shows an example of an operating point map of a rotating electric machine, with the horizontal axis representing rotation speed and the vertical axis representing torque. Figure 3 is a diagram showing star connection driving. Figure 4 is a diagram showing open connection driving. For convenience, the control unit 15 is omitted from Figures 3 and 4.

[0046] As shown in FIG. 2, the driving range of the rotating electric machine 3 is divided into two ranges depending on the rotation speed and torque. One of the driving ranges is the star connection driving range. The star connection driving range is the normal use range. The other driving range is the open connection driving range. The open connection driving range is a range with higher rotation speeds or higher torque than the star connection driving range.

[0047] When the operating point is in the star connection drive region, the control unit 15 executes star connection drive control. Star connection drive is sometimes referred to as Y drive. The control unit 15 controls the MOSFETs 8S, 9S and the changeover switch 10 so that the windings 3U, 3V, and 3W are in a star connection state. Specifically, as shown in FIG. 3, the MOSFETs of all the changeover switches 10 are turned off and the changeover switches 10 are opened. The inverter 9 is also neutralized. As shown in FIG. 3, for example, the MOSFETs 9S of the upper arms 9H of all phases may be turned on and the MOSFETs 9S of the lower arms 9L of all phases may be turned off. The MOSFETs 9S of the upper arms 9H of all phases may be turned off and the MOSFETs 9S of the lower arms 9L of all phases may be turned on. The MOSFETs 8S of the inverter 8 are then controlled according to drive requirements, etc.

[0048] FIG. 3 shows one current conduction pattern in star-connection drive. The dashed-dotted arrows in FIG. 3 indicate an example of a current path. FIG. 3 shows the current path when the MOSFET 8S in the U-phase upper arm 8H and the MOSFET 8S in the W-phase lower arm 8L are turned on. In the example shown in FIG. 3, the upper arm 9H of the inverter 9 is turned on and the lower arm 9L is turned off. The current flows in the following order: U-phase upper arm 8H → node U1 → U-phase winding 3U → node U2 → U-phase upper arm 9H → W-phase upper arm 9H → node W2 → W-phase winding 3W → node W1 → W-phase lower arm 8L. In this way, in star-connection drive, current flows without passing through the selector switch 10.

[0049] When the operating point is in the open connection drive region, the control unit 15 executes open connection drive control. Open connection drive is sometimes referred to as H drive. For example, the control unit 15 turns on the MOSFETs of all the changeover switches 10 to close the changeover switches 10. The control unit 15 may also close the changeover switch 10 of the corresponding phase when it turns on the MOSFET 9S of the upper arm 9H. The control unit 15 also opens the neutral point of the inverter 9. Opening the neutral point forms an open connection circuit of the U-phase upper and lower arm circuits 8HL, 9HL via the U-phase winding 3U. Similarly, an open connection circuit of the V-phase upper and lower arm circuits 8HL, 9HL via the V-phase winding 3V is formed. An open connection circuit of the W-phase upper and lower arm circuits 8HL, 9HL via the W-phase winding 3W is formed. The control unit 15 regards each phase as an independent open connection circuit and controls the applied voltage for each phase.

[0050] FIG. 4 shows one current conduction pattern in open-connection driving. The two-dot chain arrow in FIG. 4 indicates one example of a current path. FIG. 4 shows the current path when MOSFET 8S in W-phase lower arm 8L and MOSFET 9S in W-phase upper arm 9H are turned on. Current flows in the following order: changeover switch 10 → W-phase upper arm 9H → node W2 → W-phase winding 3W → node W1 → W-phase lower arm 8L. In this way, in open-connection driving, current flows via changeover switch 10.

[0051] As described above, the inverters 8 and 9 are capable of switching between star connection drive and open connection drive. That is, the power conversion circuit 4 is configured to be capable of switching between star connection drive and open connection drive. The power conversion circuit 4 is configured to be able to execute star connection drive. The power conversion circuit 4 is configured to be able to execute open connection drive. By executing open connection drive instead of star connection drive, it is possible to output a higher rotation speed range or a higher torque range.

[0052] <Charging using a power conversion circuit> Next, charging using the power conversion circuit 4 will be described with reference to Fig. 5. Fig. 5 shows a circuit configuration showing a state in which an external device is connected. In Fig. 5, the external device is shown in a simplified form.

[0053] As shown in FIG. 5, the external device 16 is connected to the power supply lines 5 and 6. The external device 16 is connected in parallel to the DC power supply 2. The external device 16 is an element separate from the elements constituting the drive system 1. The external device 16 may be, for example, an element external to a moving body (vehicle). An example of the external device 16 is a charger. The charger charges the DC power supply 2. The voltage supplied by the external device 16 is lower than the power supply voltage of the DC power supply 2. For example, the DC power supply 2 is 800 V, and the external device 16 (charger) is 400 V. In the rotating electric machine 3 and the power conversion circuit 4, the windings 3U, 3V, and 3W of the rotating electric machine 3 and the upper and lower arm circuit 8HL constituting the inverter 8 function as a boost circuit.

[0054] The external device 16 is connected to the drive system 1 (power conversion circuit 4) while the vehicle is stopped, for example. When the external device 16 is connected, the control unit 15 controls the inverters 8 and 9 and the selector switch 10 to boost the supply voltage of the external device 16 and charge the DC power supply 2. The boost operation may use one phase or multiple phases (multi-phase). The control unit 15 turns off the MOSFET of the selector switch 10. In this state, the control unit 15 turns on the upper arm 9H of the inverter 9 and controls the on / off of the upper and lower MOSFETs 8S of the upper and lower arm circuit 8HL in the corresponding phase.

[0055] External device 16 may be a DC power supply (external power supply) separate from DC power supply 2. The external power supply may be, for example, a secondary battery or may include a DC-AC conversion circuit. DC power supply 2 charges external device 16. The power supply voltage of external device 16 is lower than the power supply voltage of DC power supply 2. In rotating electric machine 3 and power conversion circuit 4, windings 3U, 3V, 3W of rotating electric machine 3 and upper arm 8H of inverter 8 function as a step-down circuit.

[0056] When an external device 16 is connected to the drive system 1, the control unit 15 controls the inverters 8 and 9 and the selector switch 10 to step down the power supply voltage of the DC power supply 2 and charge the external device 16. In the step-down operation, one phase or multiple phases (multi-phase) may be used. The control unit 15 turns off the MOSFET of the selector switch 10. In this state, the control unit 15 turns on the upper arm 9H of the inverter 9 and controls the on / off of the MOSFET 8S of the upper arm 8H of the corresponding phase. The MOSFET 8S of the lower arm 8L of the corresponding phase is turned off. When the MOSFET 8S of the upper arm 8H is turned off, a current flows through the diode of the lower arm 8L of the corresponding phase.

[0057] Fig. 6 shows an example of an external device connection structure corresponding to the circuit configuration shown in Fig. 5. Fig. 6 shows a connection structure between a power conversion module and an external device. Fig. 6 shows a simplified view of the external device. Fig. 6 also shows directions (X direction and Y direction) that will be described later.

[0058] The power conversion module 20 shown in FIG. 6 provides the main components of the power conversion circuit 4. The power conversion module 20 provides inverters 8 and 9, a changeover switch 10, and snubber circuits 11 and 12. The power conversion module 20 includes two circuit units 201 and 202, as described below. The power conversion module 20 includes a charging terminal 113 connected to the circuit unit 202. The power conversion module 20 converts the power supplied to the rotating electric machine 3. The power supply device 21 provides the DC power supply 2. The capacitor device 22 provides the smoothing capacitor 7. The external device 23 provides the external device 16.

[0059] The positive electrode of the power supply device 21 is electrically connected to the positive terminal of the capacitor device 22 via the P bus bar 24P. The negative electrode of the power supply device 21 is electrically connected to the negative terminal of the capacitor device 22 via the N bus bar 24N. The positive terminal of the capacitor device 22 is electrically connected to the power conversion module 20 via the P bus bar 25P. The negative terminal of the capacitor device 22 is electrically connected to the power conversion module 20 via the N bus bar 25N. The positive terminal of the external device 23 is electrically connected to the charging terminal 113 of the power conversion module 20 via the P bus bar 26P. The negative terminal of the external device 23 is electrically connected to, for example, the N bus bar 24N via the N bus bar 26N. The negative terminal of the external device 23 is connected to a position closer to the power supply device 21 than the capacitor device 22. This reduces inductance. Note that the conductive member electrically connecting corresponding elements is not limited to a bus bar. It may be a cable, a terminal, or the like.

[0060] The power conversion module 20 is connected to the winding section 3 coil via the output bus bar 27 out. The winding section 3 coil is provided in the rotating electric machine 3 and forms windings 3U, 3V, and 3W. The output bus bar 27 out electrically connects the circuit units 201 and 202 to the winding section 3 coil. The output bus bar 27 out forms at least a part of the output lines 13 and 14.

[0061] The drive system 1 has a power conversion device 18. The power conversion device 18 converts the power supplied to the rotating electric machine 3 using a power conversion module 20. The power conversion device 18 forms a power conversion circuit 4. The power conversion circuit 4 is sometimes referred to as a power conversion device. The power conversion device 18 is configured to include a power conversion module 20, a capacitor device 22, and a device housing. The device housing is a case for the power conversion device 18 and houses the power conversion module 20 and the capacitor device 22. The device housing is made of a resin material or the like. The device housing is provided with an input terminal block, an output terminal block, an external terminal block, etc. The input terminal block is a terminal block for connecting the P bus bar 24P and the N bus bar 24N. The output terminal block is a terminal block for connecting 27out. The external terminal block is a terminal block for connecting the P bus bar 26P and the N bus bar 26N.

[0062] The device housing contains at least one filter component. The filter component is a component that constitutes a filter circuit. The filter circuit is a circuit that can reduce noise such as electromagnetic noise. The filter circuit is connected in parallel to the inverters 8 and 9 and the smoothing capacitor 7. The filter circuit is composed of a coil and a capacitor.

[0063] <Current sensor> As shown in Fig. 1, the drive system 1 has a first current sensor 121 and a second current sensor 122. The current sensors 121 and 122 detect phase currents flowing through the windings 3U, 3V, and 3W of each phase. The current sensors 121 and 122 are magnetic sensors such as Hall sensors. The magnetic sensors are formed to include a sensor element such as a Hall element. The current sensors 121 and 122 may also be formed to include a resistive element such as a shunt resistor.

[0064] Current sensors 121 and 122 are provided for each of the three phases. First current sensors 121 include first current sensors 121U, 121V, and 121W. Second current sensors 122 include second current sensors 122U, 122V, and 122W. Current sensors 121U and 122U detect the current flowing through U-phase winding 3U. Current sensors 121V and 122V detect the current flowing through V-phase winding 3V. Current sensors 121W and 122W detect the current flowing through W-phase winding 3W.

[0065] Current sensors 121, 122 are provided on only one of output line 13 and output line 14. For example, current sensors 121, 122 are provided on output line 14, but not on output line 13. Current sensors 121, 122 are provided on output line 14 between windings 3U, 3V, 3W and inverter 9. Output line 13 corresponds to the first path, and output line 14 corresponds to the second path. First current sensor 121 corresponds to the first current sensor, and second current sensor 122 corresponds to the second current sensor.

[0066] The U-phase current sensors 121U and 122U detect the current flowing in the U-phase output line 14 as the current flowing in the U-phase winding 3U. The V-phase current sensors 121V and 122V detect the current flowing in the V-phase output line 14 as the current flowing in the V-phase winding 3V. The W-phase current sensors 121W and 122W detect the current flowing in the W-phase output line 14 as the current flowing in the W-phase winding 3W. In this embodiment, the output line 14 corresponds to the target path. Note that, in the output line 14, either of the current sensors 121 and 122 may be located on the winding 3U, 3V, or 3W side.

[0067] The power conversion circuit 4 has a current path through which a current flows. The current path includes power lines 5 and 6, a selector switch 10, output lines 13 and 14, and windings 3U, 3V, and 3W. Between the first current sensor 121 and the second current sensor 122, a portion of output line 13, a portion of output line 14, and windings 3U, 3V, and 3W exist as current paths. Losses such as resistance losses and heat losses are likely to occur in the current paths between the first current sensor 121 and the second current sensor 122. Losses occurring in the windings 3U, 3V, and 3W are particularly likely to be larger than losses occurring in a portion of output line 13 or a portion of output line 14. The current sensors 121 and 122 are positioned so that the windings 3U, 3V, and 3W are not present between the first current sensor 121 and the second current sensor 122. Therefore, there is little difference between the detection results of the first current sensor 121 and the second current sensor 122.

[0068] The power supply lines 5 and 6 connect the inverter 8 and the inverter 9 without passing through the windings 3U, 3V, and 3W. The power supply lines 5 and 6 correspond to direct paths. In the power supply line 5, the wiring 5A connects the inverter 8 and the inverter 9. The wiring 5A connects the upper arm 8H and the upper arm 9H. The wiring 5A corresponds to the upper direct path. In the power supply line 6, the wiring 6A connects the inverter 8 and the inverter 9. The wiring 6A connects the lower arm 8L and the lower arm 9L. The wiring 6A corresponds to the lower direct path. The power supply lines 5 and 6 electrically connect the DC power supply 2 and the inverters 8 and 9.

[0069] Current sensors 121 and 122 are communicatively connected to control unit 15. Current sensors 121 and 122 output to control unit 15 detection signals corresponding to the currents flowing through windings 3U, 3V, and 3W.

[0070] The control unit 15 performs rotation control, which is control of the rotating electric machine 3. The rotation control includes control of star connection drive and control of open connection drive. The rotation control also includes control of the power conversion circuit 4. The control of the power conversion circuit 4 includes control of the inverters 8 and 9 and control of the changeover switch 10. The control unit 15 performs rotation control by executing a rotation control process. The control unit 15 repeatedly executes the rotation control process at a predetermined control period. The control unit 15 has a function of executing the processing of each step of the rotation control process. The rotation control process will be described with reference to the flowchart of FIG. 12.

[0071] The control unit 15 performs a current detection process in step S101 shown in FIG. 12. In the current detection process, a process for detecting the current flowing through the windings 3U, 3V, and 3W is performed. In the current detection process, a first detection value I1 and a second detection value I2 are detected. The detection values ​​I1 and I2 are detection values ​​of the current flowing through the output line 14 for each of the three phases. The control unit 15 calculates the detection values ​​I1 and I2 for the U phase, V phase, and W phase, respectively, using the detection signals of the current sensors 121 and 122. The first detection value I1 is the detection result of the first current sensor 121. The second detection value I2 is the detection result of the second current sensor 122.

[0072] For example, control unit 15 calculates first detected values ​​I1U, I1V, and I1W using detection signals from first current sensors 121U, 121V, and 121W. Control unit 15 also calculates second detected values ​​I2U, I2V, and I2W using detection signals from second current sensors 122U, 122V, and 122W. Detected values ​​I1U and I2U are detected values ​​of the current flowing through U-phase winding 3U. Detected values ​​I1V and I2V are detected values ​​of the current flowing through V-phase winding 3V. Detected values ​​I1W and I2W are detected values ​​of the current flowing through W-phase winding 3W.

[0073] In step S102, the control unit 15 calculates the detection difference Idif using the detection values ​​I1 and I2. The detection difference Idif is the difference between the first detection value I1 and the second detection value I2. The control unit 15 calculates the detection difference Idif for each of the three phases. For example, the control unit 15 calculates the difference between the first detection value I1U and the second detection value I2U as the detection difference Idif for the U phase. The control unit 15 calculates the difference between the first detection value I1V and the second detection value I2V as the detection difference Idif for the V phase. The control unit 15 calculates the difference between the first detection value I1W and the second detection value I2W as the detection difference Idif for the W phase.

[0074] In step S103, the control unit 15 determines whether the detected difference Idif is greater than the difference threshold JI. When the absolute value of the detected difference Idif is greater than the difference threshold JI, the control unit 15 determines that the detected difference Idif is greater than the difference threshold JI. The difference threshold JI is a value determined in advance by testing or the like, and is stored in the memory 15b or the like. The difference threshold JI is a value that indicates that the detected difference Idif is abnormally large. The function of the control unit 15 that executes the process of step S103 corresponds to the abnormality determination unit.

[0075] The detection difference Idif may be greater than the difference threshold JI when at least one of the first detection value I1 and the second detection value I2 is abnormal. The first detection value I1 may be abnormal when an abnormality such as a failure occurs in the first current sensor 121. The second detection value I2 may be abnormal when an abnormality occurs in the second current sensor 122. The detection difference Idif being greater than the difference threshold JI is sometimes referred to as an abnormal detection value. For example, an abnormal detection value may occur in at least one of the three phases.

[0076] If the detection difference Idif is not greater than the difference threshold JI, the control unit 15 determines that no abnormality has occurred in the current sensors 121, 122. Because both the first current sensor 121 and the second current sensor 122 are provided on the output line 14, losses such as resistance loss and heat loss in the output line 14 are unlikely to occur between the first current sensor 121 and the second current sensor 122. Therefore, if no abnormality has occurred in the current sensors 121, 122, the first detection value I1 and the second detection value I2 will be approximately the same value. In this case, the detection difference Idif will be approximately zero.

[0077] If the detected difference Idif is not greater than the difference threshold JI for any of the three phases, the control unit 15 determines that no abnormality has occurred in the current sensors 121, 122, and proceeds to step S104. In step S104, the control unit 15 uses the detected values ​​I1, I2 to determine whether or not an abnormality in current flow has occurred. Examples of abnormalities in current flow include abnormalities in the power supply lines 5, 6, the selector switch 10, the output lines 13, 14, and the windings 3U, 3V, and 3W. Examples of abnormalities in the current flow paths include a short circuit, leakage current, and ground fault in the output line 14.

[0078] The control unit 15 can determine whether or not a phase-to-phase short circuit has occurred in the output lines 14. For example, if the first detection value I1W is a normal value while both the first detection values ​​I1U and I1V are abnormal values, the control unit 15 determines that a phase-to-phase short circuit has occurred, in which the U-phase output line 14 and the V-phase output line 14 are short-circuited. The control unit 15 may also determine whether or not a phase-to-phase short circuit has occurred in the output lines 14 using the second detection values ​​I2U, I2V, and I2W.

[0079] If a current supply abnormality occurs, the control unit 15 proceeds to step S115 and performs a current supply stop process. In the current supply stop process, a process for stopping current supply to the windings 3U, 3V, and 3W is performed. The control unit 15 can stop the driving of the rotating electric machine 3 by the current supply stop process. However, the current supply stop process does not necessarily stop the driving of the rotating electric machine 3. For example, if it is not possible to stop the moving body, the control unit 15 may continue the supply of current to the windings 3U, 3V, and 3W so that the rotating electric machine 3 operates at the minimum necessary output. In the current supply stop process, a notification process may be performed to notify an occupant or the like of abnormality information regarding the current supply abnormality. In the notification process, the abnormality information is notified to the occupant or the like by sound, image, or the like. The abnormality information includes the location where the current supply abnormality occurred, the type of the current supply abnormality, and the like.

[0080] If no abnormality in power supply has occurred, the control unit 15 performs normal control to drive the rotating electric machine 3 in steps S105 and S106. In step S105 of the normal control, the control unit 15 sets normal parameters. The normal parameters are control parameters used in the normal control. The control unit 15 sets one of the first detection value I1 and the second detection value I2 as the control parameter.

[0081] The control unit 15 performs normal drive processing in step S106. In the normal drive processing, processing for driving the rotating electric machine 3 is performed using control parameters. The control unit 15 drives the rotating electric machine 3 using the first detection value I1. The control unit 15 can drive the rotating electric machine 3 by star connection drive or open connection drive. The function of the control unit 15 for executing steps S105 and S106 includes a function for star connection drive of the rotating electric machine 3 and a function for open connection drive of the rotating electric machine 3.

[0082] If the detection difference Idif is greater than the difference threshold JI in at least one of the three phases, the control unit 15 determines that an abnormality in the detection value has occurred, and proceeds to step S107. In step S107, the control unit 15 performs an alert process. The alert process includes a process for notifying the occurrence of an abnormality in the current sensors 121, 122. The alert process notifies the occupants or the like of the abnormality in the current sensors 121, 122 by sound, image, or the like.

[0083] In steps S108 to S110, control unit 15 performs identification processing to identify the sensor in which the abnormality has occurred. The identification processing is processing to identify whether the abnormality has occurred in first current sensor 121 or second current sensor 122. The function of control unit 15 that executes the processing of steps S108 to S110 corresponds to the abnormality identification unit.

[0084] In step S108 of the identification process, the control unit 15 calculates a first estimated value Ia1 and a second estimated value Ia2 using the detected values ​​I1 and I2. The control unit 15 calculates the estimated values ​​Ia1 and Ia2 for the phase in which the abnormal detected value occurred among the three phases. The first estimated value Ia1 is a value obtained by estimating the first detected value I1 of one of the three phases from the first detected values ​​I1 of the remaining two phases. The second estimated value Ia2 is a value obtained by estimating the second detected value I2 of one of the three phases from the second detected values ​​I2 of the remaining two phases.

[0085] Control unit 15 calculates estimated values ​​Ia1 and Ia2 from detected values ​​I1 and I2 using current correlation information indicating the correlation between the currents flowing through windings 3U, 3V, and 3W. The current correlation information includes the correlation between the currents flowing through U-phase winding 3U, V-phase winding 3V, and W-phase winding 3W. The current correlation information also includes the correlation between the currents flowing through windings 3U, 3V, and 3W and the currents flowing through output line 13 and output line 14. The current correlation information may be a map, an arithmetic expression, a function, or the like. The current correlation information is stored in memory 15b or the like.

[0086] For example, if an abnormality in the detection value occurs in the U-phase, the control unit 15 calculates a first estimated value Ia1 of the U-phase using the first detected value I1V of the V-phase and the first detected value I1W of the W-phase. The control unit 15 also calculates a second estimated value Ia2 of the U-phase using the second detected value I2V of the V-phase and the second detected value I2W of the W-phase. The control unit 15 calculates the estimated values ​​Ia1 and Ia2 depending on the driving state of the rotating electric machine 3.

[0087] In step S109, the control unit 15 calculates a first deviation value Ib1 and a second deviation value Ib2 using the estimated values ​​Ia1 and Ia2. The deviation values ​​Ib1 and Ib2 are values ​​that indicate the magnitude of deviation between the detected values ​​I1 and I2 and the estimated values ​​Ia1 and Ia2 for a phase in which an abnormal detected value has occurred among the three phases. The control unit 15 calculates the difference between the first detected value I1 and the first estimated value Ia1 for the phase in which an abnormal detected value has occurred as the first deviation value Ib1. The control unit 15 also calculates the difference between the second detected value I2 and the second estimated value Ia2 as the second deviation value Ib2. For example, if an abnormal detected value has occurred in the U phase, the control unit 15 calculates the deviation values ​​Ib1 and Ib2 for the U phase.

[0088] In step S110, the control unit 15 uses the deviation values ​​Ib1 and Ib2 to identify the abnormal sensor. The abnormal sensor is the current sensor in which the abnormality occurred, either the first current sensor 121 or the second current sensor 122, for the phase in which the abnormal detection value occurred. The control unit 15 determines that the larger of the first deviation value Ib1 and the second deviation value Ib2 is the abnormal deviation value. For example, if the absolute value of the first deviation value Ib1 is larger than the absolute value of the second deviation value Ib2, the control unit 15 determines that the first deviation value Ib1 is the abnormal deviation value.

[0089] The control unit 15 may determine whether each of the first deviation value Ib1 and the second deviation value Ib2 is greater than a deviation threshold value. The deviation threshold value is a value determined in advance through testing or the like and stored in the memory 15b or the like. The deviation threshold value indicates that the deviation values ​​Ib1 and Ib2 are abnormally large. If the first deviation value Ib1 is greater than the deviation threshold value, the control unit 15 determines that the first deviation value Ib1 is an abnormal deviation value. If the second deviation value Ib2 is greater than the deviation threshold value, the control unit 15 determines that the second deviation value Ib2 is an abnormal deviation value. For this reason, the control unit 15 may determine that both the first deviation value Ib1 and the second deviation value Ib2 are abnormal deviation values.

[0090] The control unit 15 determines that one of the first current sensor 121 and the second current sensor 122, which was used to calculate the abnormal deviation value, is the abnormal sensor. For example, when an abnormality in the detection value occurs for the U phase and the first deviation value Ib1 is greater than the second deviation value Ib2, the control unit 15 determines that an abnormality has occurred in the first current sensor 121 of the U phase. The control unit 15 also determines that one of the first detection value I1 and the second detection value I2, which was used to calculate the abnormal deviation value, is the abnormal value.

[0091] In steps S111 to S114, the control unit 15 performs fail-safe control for driving the rotating electric machine 3 in a situation where an abnormal sensor is present. The control unit 15 sets a fail-safe parameter in step S111 of the fail-safe control. The fail-safe parameter is a control parameter used for the fail-safe control. The control unit 15 sets the non-abnormal value of the first detection value I1 or the second detection value I2 as the fail-safe parameter. For example, when the control unit 15 determines that an abnormality has occurred in the first current sensor 121 for the U phase, it sets the second detection value I2U for the U phase as the fail-safe parameter. In this case, for the V phase and the W phase, any of the first detection values ​​I1V, I1W and the second detection values ​​I2V, I2W may be set as the fail-safe parameter.

[0092] In step S112, the control unit 15 determines whether open connection driving is necessary. For example, it determines whether the rotating electric machine 3 needs to be driven at high rotation speed or high torque in order to move the moving body. If it is necessary to drive the rotating electric machine 3 at high rotation speed or high torque, the control unit 15 determines that open connection driving is necessary.

[0093] If open connection drive is necessary, the control unit 15 proceeds to step S113 and performs star connection drive processing. In the star connection drive processing, processing is performed to drive the rotating electric machine 3 in a star connection manner using fail-safe parameters. If open connection drive is not necessary, the control unit 15 proceeds to step S114 and performs open connection drive processing. In the open connection drive processing, processing is performed to drive the rotating electric machine 3 in an open connection manner using fail-safe parameters.

[0094] <Power conversion module> Next, the structure of a power conversion module will be described with reference to Figs. 7 and 8. Fig. 7 is a plan view showing an example of a power conversion module. For convenience, the sealing body is omitted from Fig. 7. Fig. 8 is a view of the power conversion module with the cooler, housing, and sealing body omitted. In other words, it is a diagram showing the circuit elements of the power conversion module. Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 7. Fig. 10 is a cross-sectional view taken along line XX in Fig. 7.

[0095] In the following, the thickness direction of the substrate is referred to as the Z direction, and the direction perpendicular to the Z direction is referred to as the X direction. The direction perpendicular to both the Z direction and the X direction is referred to as the Y direction. Unless otherwise specified, the shape viewed from the Z direction, in other words, the shape along the XY plane defined by the X and Y directions, is referred to as the planar shape. Furthermore, the planar view from the Z direction may sometimes be simply referred to as the planar view.

[0096] The power conversion module 20 provides at least a part of the above-described power conversion circuit 4. The power conversion module 20 includes a cooler 30, a housing 40, a substrate 50, a semiconductor element 60, a snubber component 70, a changeover switch 80, a clip 90, a bus bar 100, and a main terminal 110. The power conversion module 20 may further include a circuit board that provides a control unit 15. The power conversion module 20 is sometimes referred to as a semiconductor module, an inverter module, or the like. A circuit is configured by wiring members including the conductors of the substrate 50, the clip 90, and the bus bar 100, and electronic components including the semiconductor element 60, the snubber component 70, and the changeover switch 80 mounted on the substrate 50. The main terminal 110 is a terminal for external connection connected to the circuit.

[0097] The cooler 30 supports other elements constituting the power conversion module 20. The cooler 30 cools circuit elements of the power conversion module 20, such as the semiconductor device 60 and the snubber component 70. The cooler 30 is formed using a metal material such as Al or Cu. The illustrated cooler 30 has a case 31 and a lid 32. The case 31 and the lid 32 form a flow path 33 when the lid 32 is attached to the case 31. The case 31 is, for example, box-shaped with one side open. The lid 32 is fixed to the case 31 so as to close the opening of the case 31. Fins 34, for example, a plurality of pin fins, are provided on the inner surface of the lid 32. The fins 34 are arranged in the flow path 33. The flow path 33 extends, for example, in the X direction.

[0098] The cooler 30 has an inlet pipe 35 and an outlet pipe 36 provided on the side wall of the case 31. In the example shown in FIG. 9, the inlet pipe 35 is attached to the side wall on the substrate 52 side in the X direction, and the outlet pipe 36 is attached to the side wall on the substrate 51 side. A refrigerant 37 is supplied to the flow path 33 via the inlet pipe 35. The refrigerant 37 that has flowed through the flow path 33 is discharged to the outside of the cooler 30 via the outlet pipe 36. A phase-change refrigerant such as water or ammonia, or a phase-non-change refrigerant such as an ethylene glycol-based refrigerant may be used as the refrigerant 37. For example, LLC may be used as the refrigerant 37. LLC is an abbreviation for long life coolant.

[0099] The cooler 30 has one surface 301 and a back surface 302. The back surface 302 is the surface opposite to the one surface 301 in the Z direction. A substrate 50 is disposed on the one surface 301. The flow path 33 is provided so as to overlap the semiconductor element 60 and the snubber component 70 in a plan view in order to effectively cool the semiconductor element 60, the snubber component 70, and the like. The flow path 33 is provided so as to overlap most of the substrate 50 in a plan view.

[0100] The cooler 30 is not limited to the configuration having the flow path 33 described above. A heat dissipation member such as a heat sink may be used as the cooler 30. A heat sink is sometimes referred to as a heat sink or a cooling plate. The heat dissipation member may include heat dissipation fins. If insulation of the substrate 50 from the cooler 30 is not required, a bonding material such as solder or sintered Ag may be interposed between the substrate 50 and the cooler 30. In other words, the substrate 50 may be bonded to one surface 301 of the cooler 30. If insulation is required, an electrically insulating member may be disposed between the substrate 50 and the cooler 30. For example, a ceramic plate or a resin sheet may be used as the insulating member. A TIM such as silicone gel may be used to improve thermal conductivity. TIM is an abbreviation for Thermal Interface Material. A support member that does not provide a cooling function may be used instead of the cooler 30.

[0101] The housing 40 is formed using an electrically insulating material such as resin. The housing 40 may be, for example, a resin molded body. The housing 40 may hold some of the elements of the power conversion module 20. Some of the elements may be integrally molded with the housing 40 as an insert part. The housing 40 may be fixed to the cooler 30. The housing 40 may be fixed to a case (not shown) that houses the power conversion module 20 together with the cooler 30. When the housing 40 is arranged on one side of the cooler 30, it provides, together with the cooler 30, a space for accommodating electronic components such as the substrate 50 and the semiconductor element 60 mounted on the substrate 50.

[0102] The illustrated housing 40 includes a frame body 41 and a partition wall 42. The frame body 41 has a predetermined height in the Z direction and is annular so as to surround the substrate 50 in a plan view in the Z direction. The frame body 41 may be referred to as an annular wall portion. The frame body 41 may be an approximately rectangular annular portion. The rectangular annular frame body 41 has four walls 411, 412, 413, and 414.

[0103] The wall portions 411 and 412 extend substantially in the X direction. The wall portions 411 and 412 are disposed opposite each other with a predetermined gap in the Y direction. The wall portion 411 is disposed on one end side of the substrate 50 in the Y direction, and the wall portion 412 is disposed on the other end side of the substrate 50. The wall portions 413 and 414 extend in the Y direction. The wall portion 413 is continuous with the wall portions 411 and 412 at one end side in the X direction. The wall portion 414 is continuous with the wall portions 411 and 412 at the other end side in the X direction.

[0104] The partition wall 42 has a predetermined height in the Z direction and is connected to the frame body 41. The partition wall 42 divides the area defined by the frame body 41. The partition wall 42 may divide the area into multiple areas, for example, corresponding to the number of substrates 50. The partition wall 42 is sometimes referred to as a partition wall. The partition wall 42 may extend in a predetermined direction, and both ends thereof may be connected to the frame body 41. The illustrated housing 40 has two partition walls 42. The partition walls 42 extend in the Y direction, similar to the wall portions 413 and 414. One end of each partition wall 42 is connected to the wall portion 411, and the other end is connected to the wall portion 412. The two partition walls 42 and the wall portions 413 and 414 are aligned in the X direction at a predetermined interval. The partition walls 42 divide the opposing area of ​​the frame body 41 into three areas. A substrate 50 is housed in each of the three divided areas.

[0105] As illustrated, a seal 43 may be disposed in the storage space formed by the housing 40 and the cooler 30. The seal 43 is disposed in the storage space and seals the substrate 50, electronic components mounted on the substrate 50, and the like. The seal 43 is, for example, a gel or a potting resin. The seal 43 fills the storage space so as not to exceed the upper end of the frame 41. Because the storage space is divided into multiple regions by the partition walls 42 as described above, the impact of stress due to expansion and contraction of the seal 43 on the electronic components mounted on the substrate 50 and the electrical connection structure can be reduced compared to a configuration without division.

[0106] The substrate 50 provides a wiring function. The substrate 50 may also be referred to as a wiring board, a printed circuit board, or the like. A semiconductor element 60, a snubber component 70, and a changeover switch 80 are mounted on the substrate 50. The substrate 50 has, for example, a substantially rectangular planar shape. The power conversion module 20 may include a single substrate 50 or multiple substrates 50. The illustrated substrate 50 includes three substrates 51, 52, and 53.

[0107] Substrate 51, together with electronic components mounted on substrate 51, constitutes a circuit on the inverter 8 side. Substrate 52, together with electronic components mounted on substrate 52, constitutes a circuit on the inverter 9 side. Substrate 51 has an insulating substrate 511 and a conductor arranged on insulating substrate 511. Substrate 52 has an insulating substrate 521 and a conductor arranged on insulating substrate 521. Substrate 53 has an insulating substrate 531 and a conductor arranged on insulating substrate 531. Insulating substrates 511, 521, and 531 are formed using an electrically insulating material such as ceramic or resin.

[0108] The conductors are formed from metals with good electrical and thermal conductivity, such as Cu or Al. The conductors may have a plating film of Ni, Au, or the like on their surfaces. The conductors may be arranged on only one surface of the insulating substrates 511, 521, and 531, or on both one surface and the back surface. The back surfaces of the insulating substrates 511, 521, and 531 are the surfaces facing the cooler 30 in the Z direction. The conductors may be arranged inside the insulating substrates 511, 521, and 531. That is, the substrates 51, 52, and 53 may be single-sided substrates, double-sided substrates, or multilayer substrates with three or more layers including inner layer wiring. The conductors may include via conductors. The via conductors are formed by arranging a conductor, such as a plating, in through holes (vias) formed in the insulating layers that constitute the insulating substrates 511, 521, and 531. The via conductors electrically connect conductors arranged on different layers.

[0109] Substrate 51, substrate 52, and substrate 53 have different structures. Substrates 51, 52, and 53 are all substantially rectangular in plan view. Substrates 51, 52, and 53 have different planar shapes. In the Y direction, the length of substrate 51, the length of substrate 52, and the length of substrate 53 are substantially equal. In the X direction, the length of substrate 53 is shorter than the lengths of substrates 51 and 52. Substrates 51, 52, and 53 have different conductor patterns. The power conversion module 20 includes three types of substrates 50 in total.

[0110] The substrates 51, 52, and 53 are arranged on one surface 301 of the cooler 30. The substrates 51, 52, and 53 are lined up in the X direction. The substrate 53 is arranged between the substrates 51 and 52. In the X direction, the substrates 51, 53, and 52 are lined up in this order.

[0111] The illustrated substrate 51 has a conductor 512 arranged on one side and a conductor 513 arranged on the back side. The substrate 52 has a conductor 522 arranged on one side and a conductor 523 arranged on the back side. The substrate 53 has a conductor 532 arranged on one side and a conductor 533 arranged on the back side. The conductors 513, 523, and 533 are electrically isolated from the corresponding conductors 512, 522, and 532 by insulating substrates 511, 521, and 531. The conductors 513, 523, and 533 provide, for example, a heat dissipation function. The substrates 51, 52, and 53 are arranged in the cooler 30 with the conductors 513, 523, and 533 facing the cooler 30.

[0112] The conductors 512, 522, and 532 are patterned. The patterned conductors 512, 522, and 532 provide wiring functions. That is, together with the mounted electronic components, they form a circuit. The conductors 512 of the substrate 51 include a P wiring 514, an N wiring 515, an O wiring 516, and a signal wiring 517. Each wiring is electrically separated by a predetermined gap. The P wiring 514 and the N wiring 515 are power wirings. The P wiring 514 may be referred to as a positive wiring or a high-potential power line. The N wiring 515 may be referred to as a negative wiring or a low-potential power line. The O wiring 516 may be referred to as an output wiring.

[0113] The P wiring 514 is connected to the drain electrode (drain terminal) of the semiconductor element 61H. A P bus bar 101, to which the P terminal 111 is connected, is joined to the P wiring 514. The P wiring 514 electrically connects the P terminal 111 and the semiconductor element 61H. The P wiring 514 is provided for each phase of the upper and lower arm circuits 8HL that constitute the inverter 8. The P wiring 514 extends approximately in the Y direction. The three P wirings 514 are lined up in the X direction at a predetermined interval. The P wiring 514 has wirings 514A, 514B, and 514C. The wiring 514A extends in the Y direction. The wiring 514B is connected to one end of the wiring 514A, and the wiring 514C is connected to the other end.

[0114] Wiring 514B is disposed near an end of substrate 51 in the Y direction. Wiring 514B extends in the X direction from wiring 514A. P bus bar 101 is joined to wiring 514B. Wiring 514C is located in the middle of substrate 51 in the Y direction. Wiring 514C extends in the X direction from wiring 514A at the end opposite to wiring 514B. A corresponding semiconductor element 61H (drain terminal) is joined to wiring 514C.

[0115] Of the three P wirings 514 lined up in the X direction, the P wiring 514 arranged at the end closest to the substrate 52 and the P wiring 514 arranged in the middle are arranged in the same direction. Of these two P wirings 514, wirings 514B and 514C extend from wiring 514A in a direction away from the substrate 52. The remaining P wiring 514 is arranged in a mirror image of the other two, that is, in a line-symmetrical arrangement with respect to an imaginary line substantially parallel to the Y direction. In this P wiring 514, wirings 514B and 514C extend from wiring 514A in a direction approaching the substrate 52.

[0116] The N wiring 515 is electrically connected to the source electrode (source terminal) of the semiconductor element 61L via a clip 912. An N bus bar 102, to which the N terminals 112 are connected, is joined to the N wiring 515. The N wiring 515 electrically connects the N terminals 112 and the semiconductor element 61L. The N wiring 515 has wirings 515A and 515B. The wiring 515A is arranged in the middle of the substrate 51 in the Y direction. The wiring 515A is arranged between the P wiring 514 and the O wiring 516. The wiring 515A extends approximately in the X direction. The wiring 515A extends from near one end of the substrate 51 to near the other end in the X direction. The three-phase semiconductor elements 61L are commonly connected to the wiring 515A via the corresponding clips 912.

[0117] The wiring 515B extends roughly in the Y direction. The wiring 515B has roughly the same length in the Y direction as the P wiring 514 (wiring 514A). The wiring 515B is arranged alternately with the P wiring 514 in the X direction and between the P wirings 514. That is, the N wiring 515 has two wirings 515B. In the X direction, the wirings are arranged in the following order: P wiring 514, wiring 515B, P wiring 514, wiring 515B, P wiring 514. One of the ends of the wiring 515B is arranged near the end of the substrate 51 in the Y direction. The N bus bar 102 is joined to one of the ends of the wiring 515B. The other end of the wiring 515B is connected to the wiring 515A.

[0118] The O wiring 516 is connected to the drain electrode (drain terminal) of the semiconductor element 61L. The O terminal 115 is joined to the O wiring 516. The source terminal of the semiconductor element 61H is electrically connected to the O wiring 516 via a clip 911. The O wiring 516 electrically connects the source terminal of the semiconductor element 61H, the drain terminal of the semiconductor element 61L, and the O terminal 115. The O wiring 516 is provided for each phase. The O wiring 516 is aligned in the Y direction with the P wiring 514 of the corresponding phase via wiring 515A. The O wiring 516 is generally L-shaped in plan view.

[0119] The signal wiring 517 electrically connects the pads of the semiconductor elements 61H and 61L to signal terminals (not shown). The signal wiring 517 is electrically connected to the pads via, for example, bonding wires. The signal wiring 517 is, for example, a signal island formed on the corresponding substrate 51. For convenience, FIG. 5 shows one signal wiring 517 for each semiconductor element 61H, 61L. The signal wiring 517 is aligned with the corresponding semiconductor element 61H in the Y direction. The signal wiring 517 corresponding to the semiconductor element 61H is arranged closer to the wiring 514B than the semiconductor element 61H. The signal wiring 517 is aligned with the corresponding semiconductor element 61L in the X direction. The signal wiring 517 corresponding to the semiconductor element 61L is arranged closer to the substrate 52 than the semiconductor element 61L.

[0120] The upper and lower arm circuits 9HL for two phases of the inverter 9 are configured by the substrate 52 and the components mounted on the substrate 52. The upper and lower arm circuits 9HL for the remaining phase are configured by the substrate 53 and the components mounted on the substrate 53. Snubber components 72 and changeover switches 80 are provided for each phase of the upper and lower arm circuits 9HL. The snubber components 72 and changeover switches 80 are mounted on each of the substrates 53, 53.

[0121] The substrate 52 includes a P wiring 524, an N wiring 525, an O wiring 526, and a signal wiring 527. The P wiring 524 includes wirings 524D, 524E, 524F, and 524G. The wiring 524D connects the inverter 8 and the drain terminal of the changeover switch 80. The substrate 52 includes wirings 524D for two phases. The wiring 524D extends generally in the Y direction. The changeover switch 80 is disposed at one end of the wiring 524D. The drain terminal of the changeover switch 80 is connected to the wiring 524D. The changeover switches 80 for two phases are aligned in the X direction. A snubber component 72 is connected to the wiring 524D midway. The snubber component 72 is connected to the wiring 524D at a position between the connection with the wiring 524F and the connection with the changeover switch 80. The snubber components 72 for two phases are aligned in the X direction.

[0122] The wiring 524E is aligned with the wiring 524D in the Y direction. There is a predetermined gap between the wiring 524E and the wiring 524D. A semiconductor element 62H is arranged on the wiring 524E. The drain terminal of the semiconductor element 62H is connected to the wiring 524E. The semiconductor elements 62H for two phases are aligned in the X direction. The source terminal of the changeover switch 80 is electrically connected to the wiring 524E via a clip 923. The two wirings 524E are electrically connected by a clip 924 extending in the Y direction. The clip 924 electrically connects the two wirings 524E across the N wiring 525 located between the wirings 524E. One end of the P bus bar 109 is connected to the wiring 524E arranged on the substrate 53 side.

[0123] Wiring 524F electrically connects the two wirings 524D. Wiring 524F extends generally in the X direction. Wiring 524F is connected to the end of wiring 524D opposite the end where changeover switch 80 is located. One end of P bus bar 106 is connected to wiring 524F.

[0124] Wiring 524G is electrically connected to wiring 524E. Wiring 524G electrically connects the drain terminal of semiconductor element 62H and charging terminal 113. Wiring 524G extends generally in the Y direction. One end of wiring 524G is connected to wiring 524E on the far side from substrate 53. A charging terminal 113 is joined to the other end of wiring 524G. Charging terminal 113 extends generally in the Y direction. Charging terminal 113 is electrically connected to wiring 524E, 524G, which correspond to wiring 5A12.

[0125] The N wiring 525 is common to the two-phase upper and lower arm circuits 9HL. The N wiring 525 extends approximately in the Y direction. The N wiring 525 is arranged between the P wirings 524 in the X direction. The N wiring 525 runs parallel to the P wirings 524 arranged on both sides. One end of the N wiring 525 is electrically connected to the source terminal of the semiconductor element 62L via a clip 922. The N wiring 525 is electrically connected to the semiconductor elements 62L for two phases. The other end of the N wiring 525 is joined to the N terminal 114A. The N terminal 114A extends approximately in the Y direction. A snubber component 72 is connected to the N wiring 525 at a position between the connection portion of the semiconductor element 62L and the connection portion of the N terminal 114A. The snubber component 72 is commonly connected to the single N wiring 525.

[0126] Wiring 526 is aligned with wiring 524E and N wiring 525 in the Y direction. Semiconductor element 62L is arranged on wiring 526. A drain terminal of semiconductor element 62L is connected to wiring 526. Semiconductor elements 62L for two phases are aligned in the X direction. A source terminal of semiconductor element 62H is electrically connected to wiring 526 via clip 921. On wiring 526, the connection position of clip 921 and the connection position of semiconductor element 62L are aligned in the X direction. O terminal 116 is connected to wiring 526. O terminal 116 extends generally in the Y direction, in the opposite direction to charging terminal 113 and N terminal 114A.

[0127] Signal wiring 527 is provided for semiconductor elements 62H and 62L and changeover switch 80. The signal wiring 527 for changeover switch 80 and semiconductor element 62H is arranged on the opposite side of N wiring 525 in the X direction with respect to the corresponding changeover switch 80 and semiconductor element 62H. The signal wiring 527 for semiconductor element 62L is arranged on the opposite side of N wiring 525 in the Y direction with respect to the corresponding semiconductor element 62L.

[0128] Conductor 532 of substrate 53 includes P wiring 534, N wiring 535, and signal wiring 537. P wiring 534 and N wiring 535 are power wiring that connect inverter 8 and inverter 9. P wiring 534 connects P wiring 514 of substrate 51 and P wiring 524 of substrate 52. P wiring 534 extends generally in the arrangement direction of substrates 51 and 52, that is, in the X direction. P wiring 534 is divided into two in the extension direction.

[0129] The P wiring 524 has wirings 534C, 534D, 534E, and 534F. Like wiring 524D, wiring 534C connects the inverter 8 and the drain terminal of the changeover switch 80. The substrate 53 has one phase of wiring 534C. Wiring 534C extends generally in the Y direction. The changeover switch 80 is disposed at one end of wiring 534C. The drain terminal of the changeover switch 80 is connected to wiring 534C. A snubber component 72 is connected to the middle of wiring 534C. The snubber component 72 is connected to wiring 534C at a position between the connection with wiring 534E and the connection with the changeover switch 80.

[0130] The wiring 534D is aligned with the wiring 534C in the Y direction. There is a predetermined gap between the wiring 534D and the wiring 534C. A semiconductor element 62H is disposed on the wiring 534D. A drain terminal of the semiconductor element 62H is connected to the wiring 534D. A source terminal of the changeover switch 80 is electrically connected to the wiring 534D via a clip 923.

[0131] Wiring 534E electrically connects P wiring 524 formed on substrate 52 and P wiring 534 formed on substrate 53. Wiring 534E is continuous with wiring 534C. Wiring 534E extends generally in the X direction. One end of P bus bar 106 is connected to a portion of wiring 534E near the end of wiring 534E facing toward substrate 52. P bus bar 106 extends generally in the X direction. P bus bar 106 electrically connects wiring 524F and 534E. One end of P bus bar 105 is connected to a portion of wiring 534E facing toward substrate 51. P bus bar 105 extends generally in the X direction. P bus bar 105 electrically connects wiring 514A and 534E.

[0132] Wiring 534F is aligned with wiring 534D in the X direction. Wiring 534F is electrically connected to wiring 534D via clip 933. Clip 933 straddles N wiring 535. One end of P bus bar 109 is connected to wiring 534F. P bus bar 109 extends roughly in the X direction. P bus bar 109 electrically connects wirings 524E and 534F.

[0133] The N wiring 535 extends generally in the Y direction. The N wiring 535 is aligned with the P wiring 534 in the X direction. The N wiring 535 runs parallel to the P wiring 534. One end of the N wiring 535 is electrically connected to the source terminal of the semiconductor element 62L via a clip 922. The N terminal 114B is joined to the other end of the N wiring 535. The N terminal 114B extends generally in the Y direction. The N terminals 114A and 114B are power supply terminals and are connected to the capacitor device 22 together with the P terminal 111 and the N terminal 112. A snubber component 72 is connected to the N wiring 535 at a position between the connection portion of the semiconductor element 62L and the connection portion of the N terminal 114B.

[0134] The wiring 536 is aligned with the wiring 534D and the N wiring 535 in the Y direction. The semiconductor element 62L is disposed on the wiring 536. The drain terminal of the semiconductor element 62L is connected to the wiring 536. The source terminal of the semiconductor element 62H is electrically connected to the wiring 536 via a clip 921. On the wiring 536, the connection position of the clip 921 and the connection position of the semiconductor element 62L are aligned in the X direction. The O terminal 116 for one phase is connected to the wiring 536.

[0135] Signal wiring 537 is provided for semiconductor elements 62H and 62L and changeover switch 80. The signal wiring 537 for changeover switch 80 and semiconductor element 62H is arranged on the opposite side of N wiring 535 in the X direction with respect to the corresponding changeover switch 80 and semiconductor element 62H. The signal wiring 537 for semiconductor element 62L is arranged on the opposite side of N wiring 535 in the Y direction with respect to the corresponding semiconductor element 62L.

[0136] The semiconductor element 60 is an electronic component that provides the inverters 8 and 9. The semiconductor element 60 is formed by forming a vertical element on a semiconductor substrate made of silicon (Si), a wide bandgap semiconductor with a wider bandgap than silicon, or the like. Examples of wide bandgap semiconductors include silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), and diamond. The semiconductor element 60 may also be called a power element, a semiconductor chip, or the like.

[0137] The vertical element is configured to pass a main current in the thickness direction of the semiconductor element 60 (semiconductor substrate). The semiconductor element 60 is arranged so that its thickness direction is approximately parallel to the Z direction. The semiconductor element 60 has main electrodes (main terminals) on both sides in the thickness direction. In the illustrated power conversion module 20, the semiconductor element 60 is formed by forming an n-channel MOSFET as a vertical element on a semiconductor substrate made of SiC. The semiconductor element 60 has a drain electrode (drain terminal) on its bottom surface facing the substrate 50 (51, 52) and a source electrode (source terminal) on its top surface opposite the bottom surface.

[0138] When a MOSFET is turned on, a current (main current) flows between the main terminals, that is, between the drain terminal and the source terminal. If the diode is a parasitic diode, the source terminal also serves as the anode terminal, and the drain terminal also serves as the cathode terminal. The diode may be formed on a chip separate from the MOSFET. The drain terminal is the main electrode on the high potential side, and the source terminal is the main terminal on the low potential side. The drain terminal is formed over almost the entire bottom surface. The source terminal is formed on a part of the top surface.

[0139] The semiconductor element 60 has a generally rectangular shape in plan view. The semiconductor element 60 has pads, which are signal terminals, on its upper surface. The pads are formed at positions on the upper surface that are different from the source terminals. The pads include at least a gate pad.

[0140] The multiple semiconductor elements 60 include a semiconductor element 61H that constitutes the upper arm 8H, a semiconductor element 61L that constitutes the lower arm 8L, a semiconductor element 62H that constitutes the upper arm 9H, and a semiconductor element 62L that constitutes the lower arm 9L. The semiconductor elements 60 include three semiconductor elements each of 61H, 61L, 62H, and 62L. The semiconductor elements 61H, 61L, 62H, and 62L are provided for each phase. One semiconductor element 60 provides one arm. Hereinafter, the semiconductor elements 61H and 62H may be referred to as upper arm elements 61H and 62H. The semiconductor elements 61L and 62L may be referred to as lower arm elements 61L and 62L.

[0141] Semiconductor elements 61H and 61L are mounted on substrate 51. Semiconductor element 61H is arranged to overlap wiring 514C of P wiring 514 in a plan view. The drain terminal of semiconductor element 61H is joined to P wiring 514 via a bonding material such as solder (not shown). Semiconductor element 61L is arranged to overlap O wiring 516 in a plan view. The drain terminal of semiconductor element 61L is joined to O wiring 516 via a bonding material (not shown).

[0142] The semiconductor elements 61H of each phase are aligned in the X direction. The semiconductor elements 61L of each phase are aligned in the X direction. The semiconductor elements 61H, 61L of corresponding phases are aligned roughly in the Y direction. The semiconductor elements 61H, 61L of corresponding phases are arranged offset in the X direction so that only portions of them face each other in the Y direction. The semiconductor elements 61H, 61L are arranged offset by 90 degrees around an axis approximately parallel to the Z direction. The pads of the semiconductor element 61H are arranged on the wiring 514B side in the Y direction. The pads of the semiconductor element 61L are arranged on the substrate 52 side in the X direction.

[0143] Semiconductor elements 62H and 62L are mounted on the substrate 52. Semiconductor element 62H has the same structure as semiconductor element 61H. That is, semiconductor elements with the same specifications are used as semiconductor elements 61H and 62H. The arrangement of semiconductor element 62H on substrate 52 is the same as the arrangement of semiconductor element 61H on substrate 51. Semiconductor element 62L has the same structure as semiconductor element 61L. That is, semiconductor elements with the same specifications are used as semiconductor elements 61L and 62L. The arrangement of semiconductor element 62L on substrate 52 is the same as the arrangement of semiconductor element 61L on substrate 51. Semiconductor elements 61H, 61L, 62H, and 62L have common specifications.

[0144] The semiconductor element 62H is disposed so as to overlap with the wiring 524C in a plan view. The drain terminal of the semiconductor element 62H is bonded to the wiring 524C via a bonding material (not shown). The semiconductor element 62L is disposed so as to overlap with the O wiring 526 in a plan view. The drain terminal of the semiconductor element 62L is bonded to the O wiring 526 via a bonding material (not shown).

[0145] The semiconductor elements 62H of each phase are aligned in the X direction. The semiconductor elements 62L of each phase are aligned in the X direction. The semiconductor elements 62H, 62L of corresponding phases are aligned roughly in the Y direction. The semiconductor elements 62H, 62L of corresponding phases are arranged offset in the X direction so that only portions of them face each other in the Y direction. The semiconductor elements 62H, 62L are arranged offset by 90 degrees around an axis approximately parallel to the Z direction. The pads of the semiconductor element 62H are arranged on the wiring 524B side in the Y direction. The pads of the semiconductor element 62L are arranged on the opposite side of the substrate 51 in the X direction.

[0146] The snubber component 70 is an electronic component that provides a snubber circuit. The snubber component 70 includes a snubber component 71 that provides the snubber circuit 12 and a snubber component 72 that provides the snubber circuit 11. For convenience, FIGS. 7 to 9 show a simplified illustration. The snubber component 71 has at least a capacitor to provide the snubber circuit 12. The snubber component 71 is mounted on the substrate 51. As described above, the snubber component 71 is connected in parallel to the upper and lower arm circuits 8HL. The snubber component 71 electrically bridges the P wiring 514 and the N wiring 515. In the illustrated power conversion module 20, a snubber component 71 is provided for each phase. The snubber component 71 electrically bridges the wiring 514A and the wiring 515B. The snubber component 71 electrically bridges the P wiring 514 and the N wiring 515 at a position closer to the wiring 514B than the semiconductor element 61H. Of the two wirings 515B, one snubber component 71 is connected to the wiring 515B closer to the substrate 52, and two snubber components 71 are commonly connected to the wiring 515B farther from the substrate 52. The snubber components 71 for each phase are aligned in the X direction.

[0147] The snubber component 72 has the same structure as the snubber component 71. That is, snubber components with the same specifications are used as the snubber components 71, 72. The arrangement of the snubber components 72 on the substrate 52 is the same as the arrangement of the snubber components 71 on the substrate 51. In the illustrated power conversion module 20, the snubber component 72 is provided for each phase. The snubber component 72 electrically bridges the wiring 524A and the wiring 525B. The snubber component 72 electrically bridges the P wiring 524 and the N wiring 525 at a position closer to the wiring 524B than the semiconductor element 62H. Of the two wirings 525B, one snubber component 72 is connected to the wiring 525B farther from the substrate 51, and two snubber components 72 are commonly connected to the wiring 525B farther from the substrate 51. The snubber components 72 for each phase are lined up in the X direction.

[0148] The changeover switch 80 functions as the changeover switch 10 in the power conversion circuit 4. The changeover switch 80 is formed by forming a switching element on a semiconductor substrate. In the illustrated power conversion module 20, the changeover switch 80 has a configuration similar to that of the semiconductor element 60. The changeover switch 80 is formed by forming a MOSFET on the semiconductor substrate. A parasitic diode is connected in antiparallel to the MOSFET.

[0149] The clip 90 bridges the electronic component and the conductor (wiring). The clip 90 may also be referred to as a bridging member, relay member, or metal bridge. The clip 90 is a metal plate made of a highly conductive metal such as Cu or a Cu alloy. The clip 90 may be formed by punching and pressing a metal plate of a predetermined thickness. The clip 90 may also be formed using a profiled material with a different thickness in some areas. The clip 90 may have a film applied to the surface of the base material by surface treatment. The clip 90 may have a plated film of Ni, Au, or the like on its surface. The clip 90 may have a Ni plated film containing P formed on the base material. The NiP film is formed, for example, by electroless plating. Instead of Cu, Ag, Au, Al, or Mg may be used as the base material. Instead of Ni or Au, Sn, Ag, or the like may be used as the film applied to the base material.

[0150] The clip 90 includes clips 911 and 912 mounted on the substrate 51 and clips 921 and 922 mounted on the substrate 52. The clip 911 is connected to the semiconductor element 61H. The clip 911 is provided individually for the semiconductor element 61H. The clip 911 extends generally in the Y direction and electrically connects the source terminal of the semiconductor element 61H to the O wiring 516. The clip 912 is connected to the semiconductor element 61L. The clip 912 is provided individually for the semiconductor element 61L. The clip 912 extends generally in the Y direction and electrically connects the source terminal of the semiconductor element 61L to the wiring 515A of the N wiring 515. The clips 911 and 912, together with the semiconductor elements 61H and 61L, the P wiring 514, the N wiring 515, and the O wiring 516, configure the inverter 8.

[0151] The clip 921 has the same structure as the clip 911. That is, clips with the same specifications are used as the clips 911 and 921. The arrangement of the clip 921 on the substrate 52 is the same as the arrangement of the clip 911 on the substrate 51. In the illustrated power conversion module 20, the clip 922 has the same structure as the clip 912. That is, clips with the same specifications are used as the clips 912 and 922. The arrangement of the clip 922 on the substrate 52 is the same as the arrangement of the clip 912 on the substrate 51.

[0152] In the illustrated power conversion module 20, the clip 921 is connected to the semiconductor element 62H. The clip 921 is provided individually for the semiconductor element 62H. The clip 921 extends generally in the Y direction and electrically connects the source terminal of the semiconductor element 62H to the O wiring 526. The clip 922 is connected to the semiconductor element 62L. The clip 922 is provided individually for the semiconductor element 62L. The clip 922 extends generally in the Y direction and electrically connects the source terminal of the semiconductor element 62L to the wiring 525A of the N wiring 525. The clips 921 and 922, together with the semiconductor elements 62H and 62L, the P wiring 524, the N wiring 525, and the O wiring 526, configure the inverter 9.

[0153] The busbar 100 electrically connects the conductors (wiring) of the substrate 50. The busbar 100 electrically connects the conductors and the main terminals 110. The busbar 100 may also be referred to as a lead, a wiring member, or the like. The busbar 100 is a plate material formed using a metal material with good conductivity, such as Cu. In the illustrated power conversion module 20, the busbar 100 is held in the housing 40. The busbar 100 includes a P busbar 101 and an N busbar 102 mounted on the substrate 51.

[0154] P bus bar 101 commonly connects P wiring 514 provided for each phase. The portion of P bus bar 101 that connects to substrate 51 is branched into three, and each is joined to a corresponding wiring 514B. A P terminal 111 is connected to the end of P bus bar 101 opposite substrate 51 in the Y direction. N bus bar 102 commonly connects multiple wirings 515B. The portion of N bus bar 102 that connects to substrate 51 is branched into two, and each is joined to a corresponding wiring 515B. An N terminal 112 is connected to the end of N bus bar 102 opposite substrate 51 in the Y direction.

[0155] P bus bar 101 and N bus bar 102 are held (inserted) in wall portion 411 of frame body 41. The board connection portions of P bus bar 101 and N bus bar 102 protrude from wall portion 411 into the accommodation space and are joined to the corresponding wiring.

[0156] Bus bar 100 further includes P bus bars 105, 106, and 109. P bus bar 105 extends in the X direction in a plan view. One end of P bus bar 105 is joined to P wiring 514 (wiring 514A) closest to substrate 52, and the other end is joined to P wiring 534. P bus bar 106 extends in the X direction in a plan view. One end of P bus bar 106 is joined to P wiring 524 (wiring 524A) closest to substrate 51, and the other end is joined to P wiring 534. N bus bar 107 extends in the X direction in a plan view.

[0157] P bus bar 105 is held by partition wall 42 located between boards 51 and 53. P bus bar 106 is held by partition wall 42 located between boards 52 and 53. Board connection portions of P bus bars 105 and 106 protrude from partition wall 42 into the accommodation space and are joined to corresponding wiring.

[0158] Like the busbar 100, the main terminal 110 is a plate material formed using a metal material with good conductivity, such as Cu. The main terminal 110 is an external connection terminal that is electrically connected to the main terminal (main electrode) of the semiconductor element 60. The main terminal 110 includes a P terminal 111 and N terminals 112, 114A, and 114B that are power supply terminals, a charging terminal 113, and O terminals 115 and 116. In FIG. 8, the boundary between the busbar 100 and the main terminal 110 is indicated by a two-dot chain line.

[0159] The power supply terminal is an external connection terminal electrically connected to the above-described capacitor device 22 (smoothing capacitor 7). The P terminal 111 is an external connection terminal connected to the positive terminal of the capacitor device 22 via the P bus bar 25P. The P terminal 111 is connected to the P bus bar 101. The P terminal 111 may be connected to the P bus bar 101 continuously and integrally, or may be connected by joining. The P terminal 111 may also be referred to as a positive terminal, a high-potential power supply terminal, or the like. The P terminal 111 is mounted on the substrate 51 via the P bus bar 101. The P terminal 111 extends outward in the Y direction from the wall portion 411 of the frame 41 to a position where it does not overlap with the cooler 30 in a plan view.

[0160] The N terminal 112 is an external connection terminal connected to the negative terminal of the capacitor device 22 via the N bus bar 25N. The N terminal 112 is connected to the N bus bar 102. The N terminal 112 may be connected to the N bus bar 102 continuously and integrally, or may be connected by joining. The N terminal 112 may also be referred to as a negative terminal, a low-potential power supply terminal, or the like. The N terminal 112 is mounted on the substrate 51 via the N bus bar 102. The N terminal 112 extends outward in the Y direction from the wall portion 411 of the frame 41 to a position where it does not overlap with the cooler 30 in a plan view. The N terminal 112 is located closer to the substrate 52 in the X direction than the P terminal 111.

[0161] The charging terminal 113 is an external connection terminal that is connected to the positive terminal of the external device 23 via the P bus bar 26P. The charging terminal 113 is electrically connected to the P wiring 524. The charging terminal 113 is sometimes referred to as a P terminal. The charging terminal 113 is mounted on the substrate 52. The charging terminal 113 extends outward in the Y direction from the wall portion 411 of the frame body 41 to a position that does not overlap with the cooler 30 in a plan view.

[0162] The O terminals 115, 116 are electrically connected to the windings 3U, 3V, 3W of the corresponding phases of the rotating electric machine 3. The O terminals 115, 116 may be referred to as output terminals, AC terminals, etc. The O terminal 115 is joined to the O wiring 516. An O terminal 115 is provided for each phase of the upper and lower arm circuits 8HL. The O terminal 115, together with the O wiring 516, provides the output line 13. The O terminal 115 extends substantially in the Y direction from the joint with the O wiring 516. The O terminal 115 extends outward in the Y direction from the wall portion 412 of the frame body 41 to a position where it does not overlap with the cooler 30 in a plan view.

[0163] An O terminal 116 is provided for each phase of the upper and lower arm circuits 9HL. The multiple O terminals 116 include an O terminal 116 connected to the O wiring 526 and an O terminal 116 connected to the wiring 536. Two phases of O terminals 116 are connected to the wiring 526. The O terminals 116, together with the O wiring 526, provide the output line 14. The O terminals 116 extend substantially in the Y direction from a joint with the O wiring 526. The O terminals 116 extend outward in the Y direction from the wall portion 412 to a position where they do not overlap with the cooler 30 in a plan view. In the illustrated power conversion module 20, the O terminal 116 has the same structure as the O terminal 115. In other words, external connection terminals with the same specifications are used as the O terminals 115, 116.

[0164] The power conversion module 20 includes two circuit units 201 and 202 that provide a power conversion circuit 4. The circuit unit 201 includes a substrate 51 and components mounted on the substrate 51. The circuit unit 201 includes, as components mounted on the substrate 51, semiconductor elements 61H and 61L, a snubber component 71, clips 911 and 912, a P bus bar 101, and an N bus bar 102. The circuit unit 201 provides an inverter 8 and a snubber circuit 12. The circuit unit 202 includes substrates 52 and 53 and components mounted on the substrates 52 and 53. The circuit unit 202 includes, as components mounted on the substrates 52 and 53, semiconductor elements 62H and 62L, a snubber component 72, and clips 921, 922, and 923. The circuit unit 202 provides an inverter 9 and a snubber circuit 11.

[0165] In FIG. 7, in power conversion module 20, O terminal 115 is formed of a bus bar member. The bus bar member is formed of a conductive material such as copper and has conductivity. O terminal 115 forms at least a part of output line 13. O terminal 115 is included in output bus bar 27out. O terminal 115 is a member for electrically connecting inverter 8 to one end of windings 3U, 3V, 3W. O terminal 115 is electrically connected to semiconductor elements 61H, 61L via O wiring 516 etc. Semiconductor elements 61H, 61L correspond to first semiconductor elements, and O terminal 115 corresponds to the first bus bar.

[0166] The O terminal 115 extends toward the outside of the housing 40 through the outer peripheral surface 40a. The O terminal 115 extends from the wall portion 412 toward one side in the Y direction. A plurality of O terminals 115 are arranged in the X direction along the outer peripheral surface 40a. The outer peripheral surface 40a is the outer peripheral surface of the housing 40. The outer peripheral surface 40a is included in the outer surface of the housing 40. The plurality of O terminals 115 include O terminals 115a, 115b, and 115c. The O terminals 115a, 115b, and 115c are provided in different phases. For example, the O terminal 115a is provided in the U phase, the O terminal 115b is provided in the V phase, and the O terminal 115c is provided in the W phase. The X direction corresponds to the predetermined direction.

[0167] Multiple O terminals 115 and multiple semiconductor elements 61H, 61L are arranged in the X direction. The O terminals 115 and the semiconductor elements 61H, 61L are arranged in the Y direction as a whole for each phase. The O terminal 115 is provided on the opposite side of the semiconductor element 61H in the Y direction across the semiconductor element 61L.

[0168] Like O terminal 115, O terminal 116 is formed of a bus bar member. O terminal 116 forms at least a part of output line 14. O terminal 116 is included in output bus bar 27out. O terminal 116 is a member for electrically connecting inverter 9 to the other ends of windings 3U, 3V, 3W. O terminal 116 is electrically connected to semiconductor elements 62H, 62L via O wiring 526, 536, etc. Semiconductor elements 62H, 62L correspond to second semiconductor elements, and O terminal 116 corresponds to the second bus bar.

[0169] The O terminal 116 extends toward the outside of the housing 40 through the outer peripheral surface 40a. The O terminal 116 extends from the wall portion 412 toward one side in the Y direction. A plurality of the O terminals 116 are arranged in the X direction along the outer peripheral surface 40a. The O terminals 115 and 116 are arranged in the X direction. The plurality of O terminals 116 include O terminals 116a, 116b, and 116c. The O terminals 116a, 116b, and 116c are provided in different phases. For example, the O terminal 116a is provided in the U phase, the O terminal 116b is provided in the V phase, and the O terminal 116c is provided in the W phase.

[0170] A plurality of O terminals 116, semiconductor elements 62H and 62L, and changeover switches 80 are arranged in the X direction. The O terminals 116, semiconductor elements 62H and 62L, and changeover switches 80 are arranged in the Y direction for each phase as a whole. The O terminal 116 is provided on the opposite side of the changeover switch 80 in the Y direction, across the semiconductor elements 62H and 62L. The changeover switch 80 is provided in a position offset in the X direction from at least one of the semiconductor elements 62H and 62L. Furthermore, at least one of the changeover switch 80, semiconductor elements 62H, and semiconductor elements 62L is provided in a position offset in the X direction from the O terminal 116.

[0171] The multiple O terminals 115 are aligned at equal intervals in the X direction. The multiple O terminals 116 are aligned at equal intervals in the X direction. The interval between the O terminals 115 is smaller than the interval between the O terminals 116. For example, in the X direction, the distance D1 between two adjacent O terminals 115 is smaller than the distance D2 between two adjacent O terminals 116. The distance D1 is the distance between the two O terminals 115 on the outer peripheral surface 40a. The distance D2 is the distance between the two O terminals 116 on the outer peripheral surface 40a. The interval between the O terminals 115 and 116 is larger than the distance D1 and smaller than the distance D2.

[0172] In the power conversion module 20, the distance D2 is greater than the distance D1 because the changeover switch 80 is located closer to the semiconductor elements 62H and 62L than to the semiconductor elements 61H and 61L. Another reason why the distance D2 is greater than the distance D1 is that the changeover switch 80 is included only in the circuit unit 202 out of the circuit unit 201 and the circuit unit 202. Another reason why the distance D2 is greater than the distance D1 is that at least one of the semiconductor elements 62H, 62L, and the changeover switch 80 is shifted in the X direction with respect to the O-terminal 116.

[0173] The power conversion module 20 has a sensor device 130. The sensor device 130 forms current sensors 121 and 122. The sensor device 130 is provided on one of the O terminal 115 and the O terminal 116. For example, the sensor device 130 is provided on the O terminal 116, but is not provided on the O terminal 115. By providing the sensor device 130 on the O terminal 116, a configuration is realized in which the current sensors 121 and 122 are provided on the output line 114.

[0174] The sensor device 130 shown in Figures 7 and 11 is a current sensor with a core. The sensor device 130 has a first sensor element 131, a second sensor element, a sensor core 133, a sensor board 134, a sensor case 135, and a sensor bus bar 140. The sensor case 135 houses the sensor elements 131 and 132, the sensor core 133, and the sensor board 134. The sensor case 135 is made of a resin material or the like. The sensor bus bar 140 penetrates the sensor case 135 in one direction. The sensor bus bar 140 is made of a bus bar member.

[0175] The sensor elements 131 and 132 are, for example, Hall elements. The sensor elements 131 and 132 detect the current flowing through the sensor bus bar 140. The sensor elements 131 and 132 output a detection signal corresponding to the current flowing through the sensor bus bar 140. The detection signals of the sensor elements 131 and 132 form the detection signals of the current sensors 121 and 122. The sensor elements 131 and 132 detect the current by detecting magnetic flux. The sensor elements 131 and 132 output a detection signal corresponding to the amount of magnetic flux passing through them.

[0176] The sensor core 133 is a core member made of a soft magnetic material or the like. The sensor core 133 collects magnetic flux generated by a current flowing through the sensor bus bar 140. The sensor core 133 corresponds to a magnetic flux collecting core. The sensor core 133 is formed in a substantially annular shape so as to surround the outer circumferential surface of the sensor bus bar 140. The sensor core 133 extends in a direction perpendicular to the Y direction along the outer circumferential surface of the sensor bus bar 140. The sensor core 133 has a gap 133a. The gap 133a is a gap formed in the sensor core 133. A pair of end faces of the sensor core 133 face each other via the gap 133a.

[0177] The sensor elements 131 and 132 are provided in a gap 133a. In the sensor device 130, both the first sensor element 131 and the second sensor element 132 are housed in one gap 133a. For example, the first sensor element 131 and the second sensor element 132 are arranged in the Y direction along the end face of the sensor core 133. In this configuration, the angle at which the magnetic flux passes and the amount of magnetic flux tend to be the same for the first sensor element 131 and the second sensor element 132. Therefore, the detection result of the first sensor element 131 and the detection result of the second sensor element 132 tend to be the same.

[0178] The first sensor element 131 and the second sensor element 132 may be arranged in the gap 133a in either the X direction or the Z direction. In addition, in a configuration in which the sensor core 133 has a plurality of gaps 133a, the first sensor element 131 and the second sensor element 132 may be provided in different gaps 133a.

[0179] The sensor board 134 is provided with a processing circuit and the like that processes the detection results of the sensor elements 131 and 132. The processing circuit includes an amplifier circuit that amplifies the detection signals of the sensor elements 131 and 132. The sensor board 134 is electrically connected to each of the first sensor element 131 and the second sensor element 132 by conductors or the like. The signal from the first sensor element 131 and the signal from the second sensor element 132 are input to the sensor board 134 separately.

[0180] A sensor cable 136 extends from the sensor device 130. The sensor cable 136 is included in the sensor device 130. The sensor cable 136 is electrically connected to the sensor board 134. The sensor cable 136 has a plurality of electric wires. The sensor device 130 outputs the detection results of the first sensor element 131 and the second sensor element 132 together through the sensor cable 136. This makes it possible to minimize the number of cores in the sensor cable 136. For example, the sensor cable 136 has three electric wires. The first of the three wires is a signal line for outputting the detection result of the first sensor element 131. The second is a signal line for outputting the detection result of the second sensor element 132. The third is a common line shared by the first sensor element 131 and the second sensor element 132.

[0181] The sensor device 130 has a detection target portion 141. The detection target portion 141 is a target for detecting current by the sensor elements 131 and 132. The detection target portion 141 is at least a part of the sensor bus bar 140. The detection target portion 141 is a portion of the sensor bus bar 140 that is the detection target of the sensor elements 131 and 132. For example, the detection target portion 141 is a portion of the sensor bus bar 140 that is covered by the sensor core 133. The detection target portion 141 includes the portion of the sensor bus bar 140 where the sensor elements 131 and 132 are provided.

[0182] The power conversion module 20 has a plurality of sensor devices 130. The plurality of sensor devices 130 include sensor devices 130a, 130b, and 130c. The sensor devices 130a, 130b, and 130c are arranged in the X direction. The sensor device 130a is provided at the O-terminal 116a, the sensor device 130b is provided at the O-terminal 116b, and the sensor device 130c is provided at the O-terminal 116c. In the sensor device 130a, the sensor elements 131 and 132 form U-phase current sensors 121U and 122U. In the sensor device 130b, the sensor elements 131 and 132 form V-phase current sensors 121V and 122V. In the sensor device 130c, the sensor elements 131 and 132 form W-phase current sensors 121W and 122W.

[0183] Sensor device 130 is fixed to O terminal 116. In sensor device 130, one end of sensor bus bar 140 is electrically connected to O terminal 116. Sensor bus bar 140 is fixed to O terminal 116 by welding, a fastener, or the like. Sensor bus bar 140 has a shape that extends straight in the Y direction. Sensor bus bar 140 is aligned with O terminal 116 in the Y direction.

[0184] Like the O terminal 116, the sensor bus bar 140 forms at least a part of the output line 14. The sensor bus bar 140 is also included in the output bus bar 27out. The sensor bus bar 140 is a member for electrically connecting the inverter 9 to the other ends of the windings 3U, 3V, and 3W. The sensor bus bar 140 is electrically connected to the semiconductor elements 62H and 62L via the O terminal 116 and the O wiring 526 and 536, etc. The sensor bus bar 140, together with the O terminal 116, corresponds to a second bus bar.

[0185] In the power conversion module 20, the sensor elements 131 and 132 are provided on the O terminal 116 but are not provided on the O terminal 115. The sensor elements 131 and 132 are electrically connected to the semiconductor elements 62H and 62L via the O terminal 116 but are not connected to the semiconductor elements 61H and 61L. In this embodiment, the O terminal 116 and the sensor bus bar 140 correspond to the target bus bar. The O terminal 115 corresponds to the non-target bus bar. The sensor elements 131 and 132 correspond to the current detection unit. The semiconductor elements 62H and 62L correspond to the target elements. The semiconductor elements 61H and 61L correspond to the non-target elements.

[0186] In sensor device 130, detection target portion 141 is electrically connected to O terminal 116. Detection target portion 141 is included in each of sensor devices 130a, 130b, and 130c. Sensor device 130a has detection target portion 141a, sensor device 130b has detection target portion 141b, and sensor device 130c has detection target portion 141c.

[0187] The sensor bus bars 140 are arranged at equal intervals in the X direction. The interval between the sensor bus bars 140 is the same as the interval between the O terminals 116 but is smaller than the interval between the O terminals 115. For example, the distance D3 between two detection target portions 141 adjacent in the X direction is the same as the distance D2 but is larger than the distance D1. The distance between two sensor bus bars 140 adjacent in the X direction is distance D3. The distance D3 is a size that allows multiple sensor devices 130 to be arranged in the X direction. For example, the value of the distance D3 is set so that two sensor cores 133 adjacent in the X direction do not come into contact with each other. Furthermore, the distance D3 is set to a size that makes it unlikely that the detection accuracy of one of the sensor elements 131, 132 of two sensor devices 130 adjacent in the X direction will be reduced by magnetic flux generated in the other sensor bus bar 140.

[0188] The power conversion module 20 has a sensor unit 139. The sensor unit 139 is formed to include a plurality of sensor devices 130. The sensor unit 139 is a device in which a plurality of sensor devices 130 are unitized. In the sensor unit 139, the sensor cases 135 of the plurality of sensor devices 130 are integrated together. For example, the sensor cases 135 of two sensor devices 130 adjacent to each other in the X direction are connected to each other.

[0189] <Summary of the First Embodiment> According to this embodiment, both the first current sensor 121 and the second current sensor 122 detect the current flowing through one of the output lines 13 and 14. In this configuration, if no abnormality occurs in the current sensors 121 and 122, the first detection value I1 and the second detection value I2 tend to be the same or close to each other. Therefore, it is possible to detect that an abnormality has occurred in one of the first current sensor 121 and the second current sensor 122 using the detection result of the other current sensor.

[0190] Moreover, in this configuration, a difference is unlikely to occur between the first detection value I1 and the second detection value I2, due to the absence of windings 3U, 3V, and 3W between the first current sensor 121 and the second current sensor 122. Therefore, it is unlikely that the driving mode of the rotating electric machine 3 will change depending on whether one of the first detection value I1 and the second detection value I2 is used to control the rotating electric machine 3 or the other is used to control the rotating electric machine 3. Therefore, it is possible to both detect abnormalities in the current sensors 121 and 122 and improve the reliability of driving the rotating electric machine 3.

[0191] According to this embodiment, both the first current sensor 121 and the second current sensor 122 detect the current flowing through the output line 14. In this configuration, the current flowing through the output line 14 can be used to detect that an abnormality has occurred in one of the first current sensor 121 and the second current sensor 122.

[0192] According to this embodiment, the inverters 8 and 9 can be driven in a star connection to neutralize the inverter 9. When the power conversion circuit 4 is driven in a star connection, the MOSFET 9S of the inverter 9 is kept on or off to achieve the neutralization of the inverter 9. In this case, the number of times the MOSFET 9S is switched per unit time is smaller than when the power conversion circuit 4 is driven in an open connection, and therefore heat generated by the semiconductor elements 62H and 62L during operation is reduced. This prevents the heat from the semiconductor elements 62H and 62L in the power conversion module 20 from being transferred to the sensor elements 131 and 132, which would otherwise reduce the detection accuracy of the current sensors 121 and 122.

[0193] According to this embodiment, the current sensors 121 and 122 detect the current flowing through one of the output lines 13 and 14 for each of the three phases. With this configuration, the detected values ​​I1 and I2 for each of the three phases can be used as control parameters in controlling the rotating electric machine 3. For example, it is not necessary to use the detected values ​​I1 and I2 for two of the three phases and an estimated value estimated from the detected values ​​I1 and I2 for the remaining phase. Therefore, by using the detected values ​​I1 and I2 detected for each of the three phases for rotation control, it is possible to improve the reliability of driving the rotating electric machine 3.

[0194] According to this embodiment, the control unit 15 uses the detection values ​​I1 and I2 in at least one phase to determine whether an abnormality has occurred in at least one of the first current sensor 121 and the second current sensor 122. In this configuration, it is possible to accurately detect in which phase an abnormality has occurred in one of the current sensors by calculating the detection difference Idif from the detection values ​​I1 and I2.

[0195] According to this embodiment, when an abnormality occurs in the current sensors 121, 122 in one of the three phases, the control unit 15 uses the detection values ​​I1, I2 in the remaining two phases to identify in which of the first current sensor 121 and the second current sensor 122 in the one phase the abnormality has occurred. In this configuration, the control unit 15 can notify an operator or the like of information such as which of the first current sensor 121 and the second current sensor 122 the abnormality should be resolved. This reduces the workload of the operator when performing work to resolve the abnormality in the power conversion circuit 4.

[0196] According to this embodiment, in power conversion module 20, sensor elements 131 and 132 are provided on target busbars, which are O terminal 116 and sensor busbar 140, and sensor elements 131 and 132 are not provided on non-target busbar, which is O terminal 115. In this configuration, the distance between two adjacent non-target busbars in the X direction can be minimized by the amount that sensor elements 131 and 132 are not provided on the non-target busbar. This allows the installation space in the X direction for installing multiple non-target busbars to be reduced.

[0197] According to this embodiment, the distance D1 between two non-target bus bars adjacent in the X direction is smaller than the distance D3 between the detection target portions 141 of two target bus bars adjacent in the X direction. With this configuration, the installation space for installing multiple non-target bus bars can be reduced in the X direction by the amount that the distance D1 is smaller than the distance D3. Furthermore, because the distance D3 is larger than the distance D1, the distance D3 between the detection target portions 141 can be set to an appropriate value regardless of the distance D1 so that the distance D3 between the detection target portions 141 is not insufficient for the sensor elements 131, 132. This prevents a decrease in the detection accuracy of the sensor elements 131, 132 due to the distance D3 being an insufficient value for the sensor elements 131, 132.

[0198] According to this embodiment, the distance D2 between two adjacent target bus bars on the outer peripheral surface 40a in the X direction is greater than the distance D1 between two adjacent non-target bus bars on the outer peripheral surface 40a in the X direction. This configuration allows the distance D2 to be set to an appropriate value regardless of the distance D1 so that the distance D2 is sufficient for the sensor elements 131 and 132 provided on the target bus bars. Therefore, even if the target bus bars extend straight from the outer peripheral surface 40a toward the outside of the housing 40, the sensor elements 131 and 132 can be provided on the target bus bars. In other words, the target bus bars do not need to be curved in order to provide the sensor elements 131 and 132 on them. Therefore, the shape and position of the target bus bars can be determined with priority given to reducing the installation space required for installing multiple target bus bars in the X direction.

[0199] According to the present embodiment, the target bus bar is provided with a first sensor element 131 and a second sensor element 132 as multiple current detection units. In this configuration, the detection target of the first sensor element 131 and the detection target of the second sensor element 132 are the same target bus bar. Therefore, by comparing the detection result of the first sensor element 131 with the detection result of the second sensor element 132, it is possible to detect an abnormality in the first sensor element 131 or the second sensor element 132.

[0200] Moreover, in power conversion module 20, sensor elements 131 and 132 can be provided on the target bus bar so that distance D3 does not increase compared to a configuration in which one current detection unit is provided on the target bus bar. Therefore, a configuration can be realized in which abnormalities in sensor elements 131 and 132 can be detected without increasing the installation space for the target bus bar.

[0201] According to this embodiment, the first sensor element 131 and the second sensor element 132 are provided at positions where they detect magnetic flux collected by one sensor core 133. With this configuration, it is not necessary to provide individual magnetic flux collecting cores for the first sensor element 131 and the second sensor element 132 in one sensor device 130. In this way, by sharing the sensor core 133 between the first sensor element 131 and the second sensor element 132, it is possible to reduce the size of the sensor device 130 and the number of parts constituting the sensor device 130.

[0202] According to this embodiment, in the circuit unit 202, the changeover switch 80 is disposed at a position offset in the X direction from a position aligned with one of the semiconductor elements 62H, 62L toward the other. Therefore, in the circuit unit 202, the distance between two semiconductor elements 62H, 62L adjacent to each other in the X direction is likely to increase by the amount of the changeover switch 80. Furthermore, in the circuit unit 202, the O terminal 116 is disposed on the opposite side of the semiconductor elements 62H, 62L from the changeover switch 80. Therefore, the increase in the distance between the semiconductor elements 62H, 62L tends to increase the distance D1 between two O terminals 116 adjacent to each other in the X direction. In this manner, in the circuit unit 202, by utilizing the configuration in which the presence of the changeover switch 80 tends to increase the distance D1, the sensor elements 131, 132 can be provided on the target bus bar, such as the O terminal 116, without requiring the target bus bar to have a special shape.

[0203] 13 and 14 show reference examples of power conversion circuits. Fig. 13 shows an example of a current conduction pattern when star-connected driving is performed in the reference example. Fig. 14 shows a current conduction pattern with timing different from that in Fig. 4 when star-connected driving is performed. In the reference example, the symbols of related elements shown in this embodiment are indicated by adding 'r' to the end of the symbols.

[0204] The control unit performs star connection drive while switching between multiple current conduction patterns. The control unit performs star connection drive using, for example, a PWM control method. PWM is an abbreviation for Pulse Width Modulation. The multiple current conduction patterns include the zero vector current conduction patterns shown in Figures 13 and 14. The current conduction pattern shown in Figure 13 is a zero vector pattern in which all upper arms 8Hr of the inverter 8r are turned on and all lower arms 8Lr are turned off. The current conduction pattern shown in Figure 9 is a zero vector pattern in which all lower arms 8Lr of the inverter 8r are turned on and all upper arms 8Hr are turned off. The power line 5r has a wiring 5A11r connecting the inverter 8 and the selector switch 10r and a wiring 5A12r connecting the selector switch 10r and the inverter 9r.

[0205] As shown in Figures 13 and 14, in the power conversion circuit 4r of the reference example, the snubber circuit 11r connected in parallel to the inverter 9r is connected to a wiring 5A12r of the power line 5r that connects the selector switch 10r and the inverter 9r. One end of the snubber circuit 11r is connected to the wiring 5A12r of the power line 5r, and the other end is connected to the power line 6r. For convenience, Figures 13 and 14 omit the smoothing capacitor and the snubber circuit connected in parallel to the inverter 8r. Furthermore, the snubber circuit 11r is common to each phase of the inverter 9r.

[0206] In the examples shown in Figures 13 and 14, all three-phase upper arms 9Hr of inverter 9r are turned on to neutralize inverter 9r. In this state, as shown in Figure 13, when all three-phase upper arms 8Hr of inverter 8r are turned on, the voltage across capacitor 11Cr becomes approximately equal to the supply voltage of DC power supply 2r, i.e., power supply voltage Vdc. Furthermore, as shown in Figure 14, when all three-phase lower arms 8Lr of inverter 8r are turned on, the voltage across capacitor 11Cr becomes approximately 0 V (zero volts).

[0207] In contrast to the above-described reference example, in the power conversion circuit 4 of this embodiment, the snubber circuit 11 connected in parallel to the inverter 9 is connected to the wiring 5A1 connecting the inverter 8 and the changeover switch 10, rather than to the wiring 5A2. This causes the voltage across the capacitor 11C of the snubber circuit 11 to be clamped to the power supply voltage of the DC power supply 2. Therefore, when the changeover switch 10 is off (open state), that is, when the star connection is in operation, the charging and discharging operation of the capacitor 11C can be suppressed. This improves the power conversion efficiency.

[0208] As illustrated, a changeover switch 10 may be provided on the power supply line 5 electrically connected to the positive electrode of the DC power supply 2. During star connection driving, the changeover switch 10 is turned off. The changeover switch 10 cuts off the connection between the DC power supply 2 (smoothing capacitor 7) and the inverter 9. During open connection driving, the changeover switch 10 is turned on. The changeover switch 10 connects the DC power supply 2 (smoothing capacitor 7) and the inverter 9.

[0209] In this embodiment, an example has been shown in which the power conversion circuit 4 includes the snubber circuit 12, but the present invention is not limited to this.

[0210] <Modification> In the present embodiment, an example has been shown in which a changeover switch 10 and a snubber circuit 11 are provided for each phase of the upper and lower arm circuits 9HL, but the present invention is not limited to this. For example, as shown in Fig. 15 and Fig. 16, one changeover switch 10 and one snubber circuit 11 may be provided for each of the three-phase upper and lower arm circuits 9HL that constitute the inverter 9.

[0211] In the present embodiment, an example has been shown in which one end of the snubber circuit 11 is connected to the wiring 5A1 of the power supply line 5, but the present invention is not limited to this. For example, as shown in Fig. 16 and Fig. 17 , one end of the snubber circuit 11 may be connected to the wiring 5A2 of the power supply line 5. The snubber circuit 11 is electrically connected to the smoothing capacitor 7 and the DC power supply 2 via the changeover switch 10.

[0212] (Second embodiment) This embodiment is a modification based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, the changeover switch 10 is provided on the power line 5, but this is not limiting. In this embodiment, the changeover switch 10 may be provided on the power line 6.

[0213] <Power conversion circuit> FIG. 18 shows a power conversion circuit 4 provided by a power conversion module 20 according to this embodiment. In the power conversion circuit 4 shown in FIG. 18, a changeover switch 10 is provided in each of the power line 5 and the power line 6. The power line 5 has a wiring 5A. The wiring 5A is a part of the wiring that constitutes the power line 5. The wiring 5A is a part of the wiring that connects the inverter 8 and the inverter 9 in the power line 5. The power line 6 has a wiring 6A. The wiring 6A is a part of the wiring that constitutes the power line 6. The wiring 6A is a part of the wiring that connects the inverter 8 and the inverter 9 in the power line 6.

[0214] The changeover switch 10 includes changeover switches 10A and 10B. The changeover switch 10A is arranged on the wiring 5A of the power supply line 5. The changeover switch 10A is arranged on the wiring 5A so that the drain terminal of the MOSFET is on the inverter 8 side and the source terminal is on the inverter 9 side. In other words, the changeover switch 10A is arranged so that the forward direction of the diode is from the inverter 9 to the inverter 8. The changeover switch 10B is arranged on the wiring 6A of the power supply line 6. The changeover switch 10B is arranged on the wiring 6A so that the drain terminal of the MOSFET is on the inverter 9 side and the source terminal is on the inverter 8 side. In other words, the changeover switch 10B is arranged so that the forward direction of the diode is from the inverter 8 to the inverter 9.

[0215] <Power conversion module> In the previous embodiment, an example was shown in which the spacing between the O terminals 115 was smaller than the spacing between the O terminals 116, but this is not limiting. In the present embodiment, the spacing between the O terminals 115 does not have to be smaller than the spacing between the O terminals 116.

[0216] Fig. 19 is a diagram of the power conversion module 20 according to this embodiment, with the cooler 30, housing 40, and sealing body 43 omitted. Fig. 19 corresponds to Fig. 8. Although not shown in Fig. 19, the power conversion module 20 includes the cooler 30, housing 40, and sealing body 43, similar to the preceding embodiment. In Fig. 19, the outer contour of the housing 40 is shown by a two-dot chain line.

[0217] The power conversion module 20 provides the power conversion circuit 4 shown in FIG. 18. The substrates 51 and 52 have a common structure. Substrates with the same specifications are used for the substrates 51 and 52. The substrates 51 and 52 are made of the same material and have the same planar shapes. The conductor patterns are also the same. The substrate 53 has a structure different from the substrates 51 and 52. The substrates 51, 52, and 53 all have a substantially rectangular planar shape. The planar shapes of the substrates 51 and 52 and the substrate 53 are different. In the Y direction, the lengths of the substrates 51 and 52 and the substrate 53 are substantially equal. In the X direction, the length of the substrate 53 is shorter than the length of the substrates 51 and 52. The conductor patterns of the substrates 51 and 52 and the substrate 53 are different. The power conversion module 20 includes two types of substrates 50, a total of three substrates. The substrates 51 and 52 are arranged in the same orientation relative to the cooler 30.

[0218] As described above, the substrate 52 has the same configuration as the substrate 51. The substrate 52 is disposed in the same orientation as the substrate 51 with respect to the cooler 30. The conductor 522 of the substrate 52 is patterned in the same manner as the conductor 512. The conductor 522 includes a P wiring 524, an N wiring 525, an O wiring 526, and a signal wiring 527. The P wiring 524 has the same configuration as the P wiring 514. The P wiring 524 has wirings 524A, 524B, and 524C. The N wiring 525 has the same configuration as the N wiring 515. The N wiring 525 has wirings 525A and 525B. The P wiring 524 and the N wiring 525 are power supply wirings. The O wiring 526 has the same configuration as the O wiring 516. The signal wiring 527 has the same configuration as the signal wiring 517.

[0219] Conductor 532 of substrate 53 includes P wiring 534, N wiring 535, and signal wiring 537. P wiring 534 and N wiring 535 are power wiring that connects inverter 8 and inverter 9. P wiring 534 connects P wiring 514 of substrate 51 and P wiring 524 of substrate 52. P wiring 534 extends generally in the arrangement direction of substrates 51 and 52, that is, in the X direction. P wiring 534 is divided into two in the extension direction. P bus bar 105 and changeover switch 81 are joined to P wiring 534 on the substrate 51 side. Clip 931 and P bus bar 106 are joined to P wiring 534 on the substrate 52 side.

[0220] N wiring 535 connects N wiring 515 of substrate 51 and N wiring 525 of substrate 52. N wiring 535 extends roughly in the X direction. N wiring 535 is divided into two in the extension direction. N bus bar 107 and clip 932 are joined to N wiring 535 on the substrate 51 side. Changeover switch 82 and N bus bar 108 are joined to N wiring 535 on the substrate 52 side. N wiring 535 and N wirings 515, 525 (wirings 515A, 525A) are arranged on an imaginary line roughly parallel to the X direction. N wiring 535 and P wiring 534 are arranged to be shifted in the Y direction. The connection position between N wiring 535 and N wirings 515, 525 is shifted in the Y direction from the connection position between P wiring 534 and P wirings 514, 524.

[0221] The signal wiring 537 electrically connects the pad of the changeover switch 80 to a signal terminal (not shown). The signal wiring 537 is electrically connected to the pad via, for example, a bonding wire. The signal wiring 537 is, for example, a signal island formed on the corresponding substrate 53. For convenience, one signal wiring 537 is shown for one changeover switch 80 in FIG. 5. The signal wiring 537 is aligned with the changeover switch 80 in the Y direction. The signal wiring 537 is arranged on the opposite side of the N wiring 535 with respect to the changeover switch 81. The signal wiring 537 is arranged on the P wiring 534 side with respect to the changeover switch 82.

[0222] In the power conversion module 20, the changeover switch 80 is mounted on the substrate 53. The changeover switch 80 includes changeover switches 81 and 82. The changeover switches 81 and 82 are aligned approximately in the Y direction. The changeover switch 81 is provided on the P wiring 534. The changeover switch 81 is arranged so as to overlap with the P wiring 534 on the substrate 51 side in a plan view. The drain terminal of the changeover switch 81 is joined to the P wiring 534. The source terminal of the changeover switch 81 is connected to the N wiring 535 on the substrate 52 side via a clip 931. The pad of the changeover switch 81 is arranged on the side of the corresponding signal wiring 537 in the Y direction.

[0223] The changeover switch 82 is provided on the N wiring 535. The changeover switch 82 is arranged so as to overlap with the N wiring 535 on the substrate 52 side in a plan view. The drain terminal of the changeover switch 82 is joined to the N wiring 535. The source terminal of the changeover switch 82 is connected to the N wiring 535 on the substrate 51 side via a clip 932. The pad of the changeover switch 82 is arranged on the side of the corresponding signal wiring 537 in the Y direction.

[0224] The clip 90 includes clips 931 and 932 mounted on the substrate 53. The clip 931 is connected to the changeover switch 81. The clip 931 extends generally in the X direction. The clip 931 electrically connects a source terminal of the changeover switch 81 mounted on the P wiring 534 on the substrate 51 side to the P wiring 534 on the substrate 52 side. The clip 932 is connected to the changeover switch 82. The clip 932 extends generally in the X direction. The clip 932 electrically connects a source terminal of the changeover switch 82 mounted on the N wiring 535 on the substrate 52 side to the N wiring 535 on the substrate 51 side.

[0225] Busbar 100 includes P busbar 103 and N busbar 104 mounted on substrate 52. P busbar 103 has the same structure as P busbar 101. That is, busbars with the same specifications are used for P busbars 101 and 103. The arrangement of P busbar 103 on substrate 52 is the same as the arrangement of P busbar 101 on substrate 51. N busbar 104 has the same structure as N busbar 102. That is, busbars with the same specifications are used for N busbars 102 and 104. The arrangement of N busbar 104 on substrate 52 is the same as the arrangement of N busbar 102 on substrate 51.

[0226] P bus bar 103 commonly connects P wiring 524 provided for each phase. The portion of P bus bar 103 that connects to substrate 52 is branched into three, and each is joined to a corresponding wiring 524B. Charging terminal 113 is connected to the end of P bus bar 103 on the opposite side from substrate 52 in the Y direction. N bus bar 104 commonly connects multiple wirings 525B. The portion of N bus bar 104 that connects to substrate 52 is branched into two, and each is joined to a corresponding wiring 525B.

[0227] P bus bars 101, 103 and N bus bars 102, 104 are held (inserted) in wall portion 411 of frame 41. The board connection portions of P bus bars 101, 103 and N bus bars 102, 104 protrude from wall portion 411 into the accommodation space and are joined to the corresponding wiring.

[0228] Charging terminal 113 is connected to P bus bar 103. Charging terminal 113 is sometimes referred to as a P terminal because it is electrically connected to P wiring 524 via P bus bar 103. Charging terminal 113 may be connected integrally and continuously to P bus bar 103, or may be connected by joining. Charging terminal 113 is mounted on substrate 52 via P bus bar 103.

[0229] In a plan view, the position of charging terminal 113 relative to substrate 52 is different from the position of P terminal 111 relative to substrate 51. The connection position of charging terminal 113 relative to P bus bar 103 is different from the connection position of P terminal 111 relative to P bus bar 101. As shown in FIGS. 7 and 8, P terminal 111 is connected to the vicinity of the end of P bus bar 101 on the wall portion 413 side. Charging terminal 113 is connected to the vicinity of the end of P bus bar 103 on the wall portion 414 side. In the X direction, P terminal 111, N terminal 112, and charging terminal 113 are lined up in this order. In other words, charging terminal 113 is located at one end in the arrangement direction, and P terminal 111 is located at the other end.

[0230] As described above, the elements that constitute the circuit units 201 and 202 and that are related to each other have a common structure. Furthermore, the layout of the components mounted on the board 52 is substantially the same as the layout of the components mounted on the board 51. Therefore, the circuit units 201 and 202 have a common structure. Circuit units with the same specifications are used as the circuit units 201 and 202. Note that "common" or "identical" may include errors on the order of manufacturing variations.

[0231] In this embodiment, all O terminals 116 are connected to wiring 526. No O terminals 116 are connected to wiring 536. The arrangement of the O terminals 116 on substrate 52 is the same as the arrangement of the O terminals 115 on substrate 51. The spacing between the O terminals 115 and the spacing between the O terminals 116 are approximately the same. For example, the distance D1 between two O terminals 115 adjacent to each other in the X direction on outer peripheral surface 40a is approximately the same as the distance D2 between two O terminals 116 adjacent to each other in the X direction on outer peripheral surface 40a.

[0232] In sensor unit 139, distance D3 between two detection targets 141 adjacent to each other in the X direction is greater than distance D2. In sensor unit 139, at least one of multiple sensor bus bars 140 is bent in a direction away from the adjacent sensor bus bar 140 so that distance D3 is greater than distance D2.

[0233] At least one sensor bus bar 140 has a bus bar shifted portion 143 and a bus bar intersection portion 144. The bus bar shifted portion 143 is provided at a position shifted in the X direction from the 116 terminal. The bus bar shifted portion 143 extends in the Y direction, similar to the O terminal 116. The bus bar intersection portion 144 extends in a direction intersecting the bus bar shifted portion 143. The bus bar intersection portion 144 extends in the X direction from the bus bar shifted portion 143 toward the O terminal 116. The bus bar intersection portion 144 is in a state of spanning between the bus bar shifted portion 143 and the O terminal 116.

[0234] Busbar displacement portion 143 forms the end of sensor busbar 140 on the opposite side to O-terminal 116. Busbar intersection portion 144 forms the end of sensor busbar 140 on the O-terminal 116 side. Busbar intersection portion 144 is fixed to O-terminal 116. In sensor device 130, detection target portion 141 is included in busbar displacement portion 143. Detection target portion 141 is formed by at least a part of busbar displacement portion 143.

[0235] In at least one of sensor device 130a and sensor device 130b, sensor bus bar 140 is curved so that distance D3 between detection target portion 141a and detection target portion 141b is greater than distance D2 between O terminal 116a and O terminal 116b. In at least one of sensor device 130b and sensor device 130c, sensor bus bar 140 is curved so that distance D3 between detection target portion 141b and detection target portion 141c is greater than distance D2 between O terminal 116b and O terminal 116c. Distance D3 is greater than distance D1.

[0236] In the power conversion module 20, an O terminal 115 is provided at a position aligned in the Y direction with respect to the substrate 51. An O terminal 116 is also provided at a position aligned in the Y direction with respect to the substrate 52. On the other hand, neither the O terminal 115 nor the O terminal 116 is provided at a position aligned in the Y direction with respect to the substrate 53. Furthermore, the distance between the O terminal 115 and the O terminal 116, which are adjacent to each other in the X direction, is greater than both the distance D1 and the distance D2.

[0237] At least one sensor device 130 is provided at a position aligned with the substrate 51 in the Y direction. The space between the O terminal 115 and the O terminal 116 in the Y direction is used as a space for installing the sensor device 130. For example, at least a portion of the sensor bus bar 140 is provided between the O terminal 115 and the O terminal 116 in the Y direction. For example, sensor elements 131 and 132 of the sensor device 130c are provided at positions aligned with the substrate 51 in the Y direction. These sensor elements 131 and 132 are shifted toward the semiconductor elements 61H and 61L from the semiconductor elements 62H and 62L in the X direction. These sensor elements 131 and 132 are provided between the semiconductor elements 61H and 61L and the semiconductor elements 62H and 62L in the X direction.

[0238] <Summary of the second embodiment> According to this embodiment, the distance D3 between the detection target portions 141 of two target bus bars adjacent in the X direction is greater than the distance D2 at the outer peripheral surface 40a. In this configuration, by forming the target bus bars into a curved shape, it is possible to set the distance D3 to an appropriate value so that the distance D3 is sufficient for the sensor elements 131 and 132, regardless of the distance D2. Therefore, even if the distance D2 is too short for the sensor elements 131 and 132, the sensor elements 131 and 132 can be provided on the target bus bars. In other words, there is no need to change the position of the O terminal 116 to increase the distance D2 in order to provide the sensor elements 131 and 132 on the target bus bars. Therefore, even in the highly versatile power conversion module 20, the sensor elements 131 and 132 can be provided on the target bus bars simply by changing the shape of the target bus bars.

[0239] According to this embodiment, at least one of the sensor elements 131, 132 is provided at a position shifted toward the semiconductor elements 61H, 61L from the semiconductor elements 62H, 62L in the X direction. With this configuration, the sensor elements 131, 132 can be provided as far away as possible from the semiconductor elements 62H, 62L. Therefore, even if heat is generated in the semiconductor elements 62H, 62L, this heat is less likely to be transmitted to the sensor elements 131, 132. Therefore, it is possible to prevent the detection accuracy of the sensor elements 131, 132 from being reduced due to the heat from the semiconductor elements 62H, 62L.

[0240] (Third embodiment) This embodiment is a modification based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, the current sensors 121 and 122 are provided on the output line 14, but this is not limiting. In this embodiment, the current sensors 121 and 122 may be provided on the output line 13.

[0241] <Power conversion circuit> Fig. 20 shows a power conversion circuit 4 provided by a power conversion module 20 according to this embodiment. In the power conversion circuit 4 shown in Fig. 20, current sensors 121 and 122 are provided on output line 13, but not on output line 14. Current sensors 121 and 122 are provided on output line 13 between windings 3U, 3V, and 3W and inverter 8.

[0242] U-phase current sensors 121U, 122U detect the current flowing in U-phase output line 13 as the current flowing in U-phase winding 3U. V-phase current sensors 121V, 122V detect the current flowing in V-phase output line 13 as the current flowing in V-phase winding 3V. W-phase current sensors 121W, 122W detect the current flowing in W-phase output line 13 as the current flowing in W-phase winding 3W. In this embodiment, output line 13 corresponds to the target path. Note that, in output line 13, either current sensor 121 or 122 may be located on the winding 3U, 3V, or 3W side.

[0243] <Power conversion module> Fig. 21 is a diagram of the power conversion module 20 according to this embodiment, with the cooler 30, housing 40, and sealing body 43 omitted. Fig. 21 corresponds to Fig. 8. Although not shown in Fig. 21, the power conversion module 20 includes the cooler 30, housing 40, and sealing body 43, similar to the preceding embodiment. In Fig. 21, the outer contour of the housing 40 is shown by a two-dot chain line.

[0244] The power conversion module 20 provides the power conversion circuit 4 shown in Fig. 20. In this embodiment, the sensor device 130 is provided at the O terminal 115, but is not provided at the O terminal 116. By providing the sensor device 130 at the O terminal 115, a configuration is realized in which the current sensors 121 and 122 are provided at the output line 13.

[0245] The sensor device 130 is attached to the O terminal 115 even if the distance D1 is smaller than the distance D2. For example, the sensor device 130 is a coreless current sensor. The sensor device 130 does not have a sensor core 133 or a sensor bus bar 140. In the sensor device 130, the O terminal 115 is inserted into a terminal hole of the sensor case 135. The terminal hole is a hole that penetrates the sensor case 135 in the Y direction. In a configuration in which the sensor device 130 does not have the sensor bus bar 140, a part of the O terminal 115 forms the detection target portion 141. The O terminal 115 corresponds to the target bus bar, and the O terminal 116 corresponds to the non-target bus bar.

[0246] The sensor elements 131 and 132 are provided in positions as far away as possible from the changeover switch 80. For example, the changeover switch 80 is located closer to the semiconductor elements 62H and 62L than the semiconductor elements 61H and 61L, while the sensor elements 131 and 132 are located closer to the semiconductor elements 61H and 61L than the semiconductor elements 62H and 62L. In addition, the changeover switch 80 is located on the opposite side of the semiconductor elements 61H, 61L, 62H, and 62L from the changeover switch 80 in the Y direction.

[0247] <Summary of the third embodiment> According to this embodiment, both the first current sensor 121 and the second current sensor 122 detect the current flowing through the output line 13. In this configuration, the current flowing through the output line 13 can be used to detect that an abnormality has occurred in one of the first current sensor 121 and the second current sensor 122.

[0248] According to this embodiment, the changeover switch 80 is located closer to the semiconductor elements 62H and 62L than the semiconductor elements 61H and 61L. In this configuration, the changeover switch 80 is located as far away as possible from the semiconductor elements 61H and 61L. Therefore, even if heat is generated in the changeover switch 80, the heat is less likely to be transmitted to the semiconductor elements 61H and 61L. By making it difficult for the heat of the changeover switch 80 to be transmitted to the semiconductor elements 61H and 61L, the heat of the changeover switch 80 is less likely to be transmitted to the O terminal 115 that forms at least a part of the output line 13. This makes it difficult for the heat of the changeover switch 80 to be transmitted to the sensor elements 131 and 132 that form the current sensors 121 and 122. Therefore, even if heat is generated in the changeover switch 80, it is possible to prevent the detection accuracy of the current sensors 121 and 122 from being reduced due to the heat.

[0249] (Fourth embodiment) This embodiment is a modification based on the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, the current sensors 121 and 122 are provided for each of the three phases, but this is not limited to this. In this embodiment, the current sensors 121 and 122 may be provided for at least one of the three phases.

[0250] <Power conversion circuit> Fig. 22 shows a power conversion circuit 4 provided by a power conversion module 20 according to this embodiment. In the power conversion circuit 4 shown in Fig. 22, current sensors 121 and 122 are provided in the output lines 14 of two of the three phases, but are not provided in the output line 14 of the remaining phase. For example, current sensors 121 and 122 are provided in the U-phase output line 14 and the V-phase output line 14, respectively, but are not provided in the W-phase output line 14.

[0251] The control unit 15 controls the driving of the rotating electric machine 3 using the detected values ​​I1 and I2 of two of the three phases. For example, the control unit 15 performs normal driving processing similar to the first embodiment using the detected values ​​I1 and I2 of the two phases. In the normal driving processing, the control unit 15 calculates the current of the remaining phase as a current estimation value using the detected values ​​I1 and I2 of the two phases. For example, the control unit 15 detects the first detected value I1U of the U phase and the first detected value I1V of the V phase, and calculates the current estimation value of the W phase. Then, similar to steps S105 and S106 of the first embodiment, the control unit 15 sets the first detected value I1U of the U phase, the first detected value I1V of the V phase, and the current estimation value of the W phase as normal parameters, and performs normal driving processing.

[0252] 23, the sensor device 130 is provided at the O terminals 115, 116 for two phases out of the O terminals 115, 116 for three phases. For example, the sensor device 130 is provided at each of the O terminals 116a and 116b. On the other hand, the sensor device 130 is not provided at the O terminal 116c.

[0253] (Other embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and / or elements from the embodiments. The disclosure encompasses the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are defined by the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the claims.

[0254] The disclosure in the specification, drawings, etc. is not limited by the claims. The disclosure in the specification, drawings, etc. encompasses the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification, drawings, etc. without being bound by the claims.

[0255] When an element or layer is referred to as being "on," "coupled," "connected," or "bonded," it may be directly on, coupled, connected, or bonded to the other element or layer, and intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly coupled," "directly connected," or "directly bonded" to another element or layer, no intervening elements or layers are present. Other language used to describe relationships between elements should be construed in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.).

[0256] As used in this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items, i.e., reference to A and / or B means at least one of A and B, and may include A only, B only, or both A and B.

[0257] Spatially relative terms such as "inside," "outside," "back," "below," "low," "top," "top," and the like are used herein to facilitate the description of one element or feature's relationship to other elements or features, as illustrated. Spatially relative terms may be intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures were turned over, elements described as "below" or "directly below" other elements or features would then be oriented "above" the other elements or features. Thus, the term "bottom" can encompass both an orientation of top and bottom. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used in this specification would be interpreted accordingly.

[0258] In each of the above embodiments, the control unit 15 may use at least one of the first detection value I1 and the second detection value I2 to control the rotating electric machine 3. The control unit 15 may calculate a control parameter using the first detection value I1 and the second detection value I2. For example, the control unit 15 may calculate an average value of the first detection value I1 and the second detection value I2 and set this average value as the control parameter. In this configuration, when an abnormality occurs in one of the first current sensor 121 and the second current sensor 122, the control unit 15 may set the detection value detected by the one that is not abnormal as the control parameter.

[0259] In each of the above embodiments, the sensor elements 131 and 132 serving as current detectors may be disposed in any manner relative to the detection target portion 141. For example, in the first embodiment, the sensor core 133 may be provided separately for each of the first sensor element 131 and the second sensor element 132. Furthermore, the multiple sensor elements 131 and 132 may be disposed at positions shifted from each other in the Y direction. For example, in the first embodiment, the multiple sensor elements 131 and 132 may include the sensor elements 131 and 132 provided on the O terminal 116 and the sensor elements 131 and 132 provided on the sensor bus bar 140. Furthermore, the sensor device 130 and the sensor elements 131 and 132 may not be included in the power conversion module 20. Even in this configuration, the sensor device 130 and the sensor elements 131 and 132 are included in the power conversion device 18.

[0260] In each of the above embodiments, the current sensors 121, 122 may be provided on either the output line 13 or the output line 14 for multiple phases. The current sensors 121, 122 may be provided on the output line 13 for two of the three phases, and on the output line 14 for the remaining phase. For example, the current sensors 121, 122 may be provided on the output line 13 for the U phase and the V phase, and on the output line 14 for the W phase.

[0261] In each of the above embodiments, the current sensors 121, 122 may be provided in at least one of the three phases. For example, the current sensors 121, 122 may be provided in one of the output lines 13 and 14 in the U phase, while not in either the output line 13 or the output line 14 in the V phase or the W phase. Even in this configuration, it is preferable that the second current sensor 122 be provided in the same phase as the phase in which the first current sensor 121 is provided.

[0262] In each of the above embodiments, the drive system 1 may have a 3×n rotating electric machine 3. This drive system 1 has a 3×n power conversion circuit 4 to drive the 3×n rotating electric machine 3, where n is a natural number. For example, in the drive system 1, the 3×n power conversion circuit 4 is realized by connecting n three-phase inverters 8, 9 in parallel to the n×3-phase rotating electric machine 3.

[0263] In each of the above embodiments, the wiring 5A, 6A may directly or indirectly connect the inverter 8 and the inverter 9. For example, the wiring 5A, 6A may electrically connect the inverter 9 and the DC power supply 2 without passing through the inverter 8. In this configuration, the wiring 5A, 6A also indirectly connects the inverter 8 and the inverter 9 via the DC power supply 2.

[0264] (Disclosure of technical ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be written in a multiple dependent form, with the subsequent clause referring to the preceding clause as an alternative. Furthermore, some clauses may be written in a multiple dependent form, referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0265] (Technical thought 1) A power conversion module (20) that converts power supplied to a rotating electric machine (3), a first semiconductor element (61H, 61L) constituting a first inverter (8) connected to one end of a winding of the rotating electric machine via a first path (13); second semiconductor elements (62H, 62L) constituting a second inverter (9) connected to the other end of the winding via a second path (14); a first bus bar (115) arranged in a predetermined direction (X), electrically connected to the first semiconductor element so as to form a part of the first path, and for connecting the first inverter to the one end; a second bus bar (116, 140) arranged in the predetermined direction, electrically connected to the second semiconductor element so as to form a part of the second path, and for connecting the second inverter to the other end; a current detection unit (131, 132) provided on a target bus bar (116, 140; 115) that is one of the first bus bar and the second bus bar, and that detects a current flowing through the target bus bar; Equipped with The other of the first bus bar and the second bus bar is a non-target bus bar (115; 116) on which the current detection unit is not provided.

[0266] (Technical thought 2) The target bus bar has a detection target portion (141) on which the current detection portion is provided, A power conversion module described in technical idea 1, wherein the distance (D1) between two adjacent non-target busbars in the specified direction is smaller than the distance (D3) between the respective detection target portions of two adjacent target busbars in the specified direction.

[0267] (Technical Thought 3) a housing (40) that houses the first semiconductor element and the second semiconductor element; the first bus bar and the second bus bar extend through an outer surface (40a) of the housing toward the outside of the housing, A power conversion module described in Technical Idea 1 or 2, wherein the distance (D2) between two adjacent target bus bars in the specified direction on the outer surface is greater than the distance (D1) between two adjacent non-target bus bars in the specified direction on the outer surface.

[0268] (Technical Thought 4) a housing (40) that houses the first semiconductor element and the second semiconductor element; the first bus bar and the second bus bar extend through an outer surface (40a) of the housing toward the outside of the housing, The target bus bar has a detection target portion (141) on which the current detection portion is provided, A power conversion module described in any one of technical ideas 1 to 3, wherein the distance (D3) between the detection target portions of two adjacent target bus bars in the specified direction is greater than the distance (D2) on the outer surface.

[0269] (Technical Thought 5) The power conversion module according to any one of Technical Concepts 1 to 4, wherein a plurality of the current detection units are provided on the target bus bar.

[0270] (Technical Thought 6) a magnetic flux collecting core (133) provided on the target bus bar to collect magnetic flux; The power conversion module according to Technical Idea 5, wherein all of the plurality of current detection units are provided at positions where they can detect the magnetic flux collected by the magnetic flux collecting core.

[0271] (Technical Thought 7) a changeover switch (80) that is provided in a path connecting the first inverter and the second inverter, and that connects a DC power source (2) and the second inverter in a closed state and cuts off the connection between the DC power source and the second inverter in an open state; Equipped with one of the first semiconductor element and the second semiconductor element is a target element (62H, 62L) connected to the target bus bar, the changeover switch is provided at a position shifted in the predetermined direction from a position aligned with one of the two target elements adjacent in the predetermined direction toward the other side, The power conversion module according to any one of Technical Concepts 1 to 6, wherein the target bus bar is provided on the opposite side of the target element from the changeover switch.

[0272] (Technical Thought 8) a changeover switch (80) that is provided in a path connecting the first inverter and the second inverter, and that connects a DC power source (2) and the second inverter in a closed state and cuts off the connection between the DC power source and the second inverter in an open state; Equipped with the first semiconductor element and the second semiconductor element are arranged in the predetermined direction via the changeover switch, one of the first semiconductor element and the second semiconductor element is a target element (62H, 62L) connected to the target bus bar, and the other is a non-target element (61H, 61L) connected to the non-target bus bar; A power conversion module described in any one of technical ideas 1 to 7, wherein at least one of the current detection units is arranged at a position shifted in the specified direction from a position aligned with the target element toward the non-target element.

[0273] (Technical Thought 9) A power conversion device (18) including a power conversion module (20) for converting power supplied to a rotating electric machine (3) by the power conversion module, The power conversion module includes: a first semiconductor element (61H, 61L) constituting a first inverter (8) connected to one end of a winding of the rotating electric machine via a first path (13); second semiconductor elements (62H, 62L) constituting a second inverter (9) connected to the other end of the winding via a second path (14); a first bus bar (115) arranged in a predetermined direction (X), electrically connected to the first semiconductor element so as to form a part of the first path, and for connecting the first inverter to the one end; a second bus bar (116, 140) arranged in the predetermined direction, electrically connected to the second semiconductor element so as to form a part of the second path, and for connecting the second inverter to the other end; It has moreover, a current detection unit (131, 132) provided on a target bus bar (116, 140) that is one of the first bus bar and the second bus bar, and detecting a current flowing through the target bus bar; The other of the first bus bar and the second bus bar is a non-target bus bar (115) on which the current detection unit is not provided. [Explanation of symbols]

[0274] 2... DC power supply as power supply unit, 3... rotating electric machine, 3U, 3V, 3W... winding, 8... inverter as first inverter, 9... inverter as second inverter, 13... output line as first path, 14... output line as second path, 18... power conversion device, 20... power conversion module, 40... housing, 41a... outer peripheral surface as outer surface, 61H, 61L... first semiconductor element and semiconductor element as non-target element, 62H, 62L... second semiconductor element and semiconductor as target element Elements, 80, 81, 82...switching switch, 115...first bus bar, O terminal as target bus bar and non-target bus bar, 116...second bus bar, O terminal as target bus bar and non-target bus bar, 131...first sensor element as current detection unit, 132...second sensor element as current detection unit, 133...sensor core as magnetic collecting core, 140...second bus bar, sensor bus bar as target bus bar and non-target bus bar, 141...detection target unit, D1, D2, D3...distance.

Claims

1. A power conversion module (20) that converts power supplied to a rotating electric machine (3), a first semiconductor element (61H, 61L) constituting a first inverter (8) connected to one end of a winding of the rotating electric machine via a first path (13); a second semiconductor element (62H, 62L) constituting a second inverter (9) connected to the other end of the winding via a second path (14); a first bus bar (115) arranged in a predetermined direction (X), electrically connected to the first semiconductor element so as to form a part of the first path, and for connecting the first inverter to the one end; a second bus bar (116, 140) arranged in the predetermined direction, electrically connected to the second semiconductor element so as to form a part of the second path, and for connecting the second inverter to the other end; a current detection unit (131, 132) provided on a target bus bar (116, 140; 115) that is one of the first bus bar and the second bus bar, and detecting a current flowing through the target bus bar; Equipped with The other of the first bus bar and the second bus bar is a non-target bus bar (115; 116) that is not provided with the current detection unit.

2. The target bus bar has a detection target portion (141) on which the current detection portion is provided, 2. The power conversion module according to claim 1, wherein a distance (D1) between two adjacent non-target bus bars in the predetermined direction is smaller than a distance (D3) between the detection target portions of two adjacent target bus bars in the predetermined direction.

3. a housing (40) that houses the first semiconductor element and the second semiconductor element; the first bus bar and the second bus bar extend through an outer surface (40a) of the housing toward the outside of the housing, 3. The power conversion module according to claim 1, wherein a distance (D2) between two adjacent target bus bars in the predetermined direction on the outer surface is greater than a distance (D1) between two adjacent non-target bus bars in the predetermined direction on the outer surface.

4. a housing (40) that houses the first semiconductor element and the second semiconductor element; the first bus bar and the second bus bar extend through an outer surface (40a) of the housing toward the outside of the housing, The target bus bar has a detection target portion (141) on which the current detection portion is provided, The power conversion module according to claim 1 or 2, wherein a distance (D3) between the detection target portions of two target bus bars adjacent to each other in the predetermined direction is greater than a distance (D2) between the detection target portions on the outer surface.

5. The power conversion module according to claim 1 , wherein a plurality of the current detection units are provided on the target bus bar.

6. a magnetic flux collecting core (133) provided on the target bus bar and collecting magnetic flux; The power conversion module according to claim 5 , wherein each of the plurality of current detection units is provided at a position where it detects the magnetic flux collected by the magnetic flux collecting core.

7. a changeover switch (80) that is provided in a path connecting the first inverter and the second inverter, and that connects a DC power source (2) and the second inverter in a closed state and cuts off the connection between the DC power source and the second inverter in an open state; Equipped with one of the first semiconductor element and the second semiconductor element is a target element (62H, 62L) connected to the target bus bar, the changeover switch is provided at a position shifted in the predetermined direction from a position aligned with one of the two target elements adjacent in the predetermined direction toward the other side, The power conversion module according to claim 1 or 2, wherein the target bus bar is provided on an opposite side of the target element from the changeover switch.

8. a changeover switch (80) that is provided in a path connecting the first inverter and the second inverter, and that connects a DC power source (2) and the second inverter in a closed state and cuts off the connection between the DC power source and the second inverter in an open state; Equipped with the first semiconductor element and the second semiconductor element are arranged in the predetermined direction via the changeover switch, one of the first semiconductor element and the second semiconductor element is a target element (62H, 62L) connected to the target bus bar, and the other is a non-target element (61H, 61L) connected to the non-target bus bar; The power conversion module according to claim 1 , wherein at least one of the current detection units is provided at a position shifted in the predetermined direction from a position aligned with the target element toward the non-target element.

9. A power conversion device (18) including a power conversion module (20) for converting power supplied to a rotating electric machine (3) by the power conversion module, The power conversion module includes: a first semiconductor element (61H, 61L) constituting a first inverter (8) connected to one end of a winding of the rotating electric machine via a first path (13); a second semiconductor element (62H, 62L) constituting a second inverter (9) connected to the other end of the winding via a second path (14); a first bus bar (115) arranged in a predetermined direction (X), electrically connected to the first semiconductor element so as to form a part of the first path, and for connecting the first inverter to the one end; a second bus bar (116, 140) arranged in the predetermined direction, electrically connected to the second semiconductor element so as to form a part of the second path, and for connecting the second inverter to the other end; It has moreover, a current detection unit (131, 132) provided on a target bus bar (116, 140) that is one of the first bus bar and the second bus bar, and detecting a current flowing through the target bus bar; The other of the first bus bar and the second bus bar is a non-target bus bar (115) that is not provided with the current detection unit.

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