Power converter

Abstract

To provide electric power conversion equipment having high heat dissipation effect.SOLUTION: An inverter device 80 has an inverter housing 90 and arm switch portions 530. The inverter housing 90 has an inverter external wall 91 and an inverter fin 92. The inverter external wall 91 has an outer periphery 90a and an inner periphery 90b, and extends in an annular shape with an inverter axis line Ci as the center. The inverter fin 92 is provided on the outer periphery 90a, and extends radially outward from the outer periphery 90a. A plurality of arm switch portions 530 are arranged in a circumferential direction CD and fixed to the inner periphery 90b. The arm switch portions 530 are heat generation components generating heat by being energized. Heat propagated from the arm switch portions 530 to the inner periphery 90b is dissipated to the outside from the outer periphery 90a at the inverter external wall 91.SELECTED DRAWING: Figure 26

Description

Technical Field

[0001] The disclosure in this specification relates to a power conversion device.

Background Art

[0002] Patent Document 1 describes a power conversion device. In this power conversion device, a plurality of semiconductor modules are housed in a case. The semiconductor module is a heat-generating component that generates heat when energized. The plurality of semiconductor modules are stacked in the thickness direction of the outer peripheral wall of the case. The plurality of semiconductor modules are cooled by a cooling mechanism using a refrigerant inside the case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration where the semiconductor modules are stacked in the thickness direction of the outer peripheral wall inside the case, it is difficult for the heat of the semiconductor modules to be released from the outer peripheral wall. For example, among two adjacent semiconductor modules in the thickness direction of the outer peripheral wall, the heat generated from the semiconductor module farther from the outer peripheral wall is difficult to reach the outer peripheral wall, such as being applied to the semiconductor module closer to the outer peripheral wall. Therefore, there is a concern that the heat dissipation effect of the power conversion device may decrease.

[0005] The main object of the present disclosure is to provide a power conversion device with a high heat dissipation effect.

Means for Solving the Problems

[0006] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. Furthermore, the claims and the reference numerals in parentheses in this section are merely examples illustrating the correspondence with specific means described later in the embodiments, and do not limit the technical scope.

[0007] To achieve the above objectives, the disclosed aspects are: A power converter (80) that converts electricity, Case (90) having an outer peripheral wall (91) that extends in a ring shape, Multiple heat-generating components (530) are arranged in the circumferential direction (CD) of the outer wall, are in contact with the inner circumferential surface (90b) of the outer wall, and generate heat when an electric current is applied. Multiple small heat-generating components (524, 580) are arranged in the circumferential direction, and their heat generation due to electrical current is less than that of the heat-generating components. A dense region (Asw1) is provided in which multiple heat-generating components are arranged in a circumferential direction and are densely packed together, There are no heat-generating components, multiple units are arranged in the circumferential direction, and an intermediate region (Asw2) is provided between two adjacent densely packed regions in the circumferential direction. An external connector (96) is provided in the intermediate region of the outer wall for connecting a heat-generating component to an external device (31) in a way that allows power to be supplied. Equipped with, The outer surface (90a) of the outer wall is a heat dissipation surface that releases heat transferred from the heat-generating components to the inner surface to the outside; it is a power conversion device. The disclosed aspects are: A power converter (80) that converts electricity, Case (90) having an outer peripheral wall (91) that extends in a ring shape, Multiple heat-generating components (530) are arranged in the circumferential direction (CD) of the outer wall, are in contact with the inner circumferential surface (90b) of the outer wall, and generate heat when an electric current is applied. Equipped with, The outer surface (90a) of the outer wall is a heat dissipation surface that releases heat transferred from the heat-generating component to the inner surface to the outside. The heat-generating component has a plate-shaped component body (531) and component terminals (532-535) extending from the component body, with the outer surface (531b) of the component body overlapping the inner surface and in contact with the outer peripheral wall. moreover, A connection board (510, 550) to which component terminals are connected, A substrate support part (500) fixed to the outer periphery wall and supporting the connecting substrate, It is a power conversion device equipped with [a specific feature / ability].

[0008] According to the above aspect, a plurality of heat generating components are arranged in the circumferential direction and are in contact with the inner peripheral surface of the outer peripheral wall. In this configuration, in each of the plurality of heat generating components, the generated heat is likely to be directly transmitted to the inner peripheral surface of the outer peripheral wall. Moreover, since the outer peripheral surface of the outer peripheral wall is a heat dissipation surface, the heat transmitted from the heat generating component to the outer peripheral wall is likely to be released to the outside from the outer peripheral surface. Therefore, it is possible to suppress the temperature of the heat generating component from becoming excessively high, and the heat generated from one heat generating component from being applied to other heat generating components. Therefore, the heat dissipation effect of the power conversion device can be enhanced.

Brief Description of the Drawings

[0009] [Figure 1] A diagram showing the electrical configuration of the drive system in the first embodiment. [Figure 2] Perspective view of the EPU. [Figure 3] Perspective view of the motor device and the inverter device. [Figure 4] Schematic front view of the motor device and the inverter device. [Figure 5] Plan view of the inside of the inverter device in configuration group A as viewed from the high-voltage side. [Figure 6] Plan view of the inside of the inverter device as viewed from the low-voltage side. [Figure 7] Cross-sectional view taken along line VII-VII of FIG. 6. [Figure 8] Plan view of the inverter housing and the arm switch section as viewed from the high-voltage side. [Figure 9] Plan view of the inverter housing and the arm switch section as viewed from the low-voltage side. [Figure 10] Schematic longitudinal sectional view around the arm switch section in the inverter device. [Figure 11] Perspective view showing the internal structure of the high-voltage substrate as viewed from the low-voltage side in configuration group B. [Figure 12] Plan view for showing the configuration of the P bus bar and the N bus bar in the inverter device [Figure 13] Plan view for showing the configuration of the output bus bar in the inverter device [Figure 14]Plan view showing the configuration of the earth busbar in an inverter device. [Figure 15] A circuit diagram illustrating the parasitic inductance in a busbar. [Figure 16] A schematic perspective view of the area around the arm switch section on a high-voltage circuit board. [Figure 17] Plan view of a high-voltage circuit board after disassembly. [Figure 18] A circuit diagram illustrating the output current, P current, and N current. [Figure 19] An exploded plan view of the high-voltage circuit board to illustrate the output current, P current, and N current. [Figure 20] A circuit diagram to explain current imbalance. [Figure 21] A diagram showing switch current to explain current imbalance. [Figure 22] Circuit diagram illustrating Comparative Example 2. [Figure 23] A plan view of the inside of the inverter device in configuration group C, seen from the high-voltage side. [Figure 24] A schematic longitudinal cross-sectional view of the area around the arm switch. [Figure 25] A view of the area around the arm switch section from the outer circumferential direction. [Figure 26] A plan view of the inside of the inverter device in configuration group D, seen from the high-voltage side. [Figure 27] A schematic longitudinal cross-sectional view illustrating the heat dissipation path of the arm switch section. [Figure 28] A schematic plan view illustrating the heat dissipation path of the arm switch section. [Figure 29] A schematic perspective view of the area around the arm switch portion of the high-voltage circuit board in the second embodiment and component group B. [Figure 30] Plan view of a high-voltage circuit board after disassembly. [Figure 31] A circuit diagram showing the output current, P current, and N current. [Figure 32] An exploded plan view of the high-voltage circuit board to illustrate the output current, P current, and N current. [Figure 33]An exploded plan view of the high-voltage substrate in the third embodiment. [Figure 34] An exploded plan view of the high-voltage circuit board to illustrate the output current, P current, and N current. [Figure 35] A perspective view showing the internal structure of the high-voltage substrate as seen from the low-pressure side in the fourth embodiment. [Figure 36] A schematic longitudinal cross-sectional view of the area around the arm switch in the fifth embodiment and component group C. [Figure 37] A view of the area around the arm switch in the sixth embodiment, seen from the circumferential outer direction. [Figure 38] A view of the area around the arm switch in the seventh embodiment, seen from the circumferential outer side. [Figure 39] A view of the area around the arm switch in the eighth embodiment, seen from the circumferential outer side. [Figure 40] Perspective view showing a modified EPU. [Figure 41] Perspective view showing a modified EPU. [Modes for carrying out the invention]

[0010] Several embodiments for implementing this disclosure are described below with reference to the drawings. In each embodiment, parts corresponding to matters described in a preceding embodiment are denoted by the same reference numerals, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, other parts of the configuration can be applied to other embodiments described in advance. Not only are combinations of parts that are explicitly shown to be combinable in each embodiment possible, but embodiments can also be partially combined even if not explicitly shown, as long as there are no particular problems with the combination.

[0011] <First Embodiment> The drive system 30 shown in Figure 1 is mounted on a mobile vehicle such as a vehicle or an aircraft. Examples of vehicles on which the drive system 30 is mounted include electric vehicles (EVs), hybrid vehicles (HVs), and fuel cell vehicles. Examples of aircraft include vertical take-off and landing aircraft, rotary-wing aircraft, and fixed-wing aircraft. These aircraft are sometimes referred to as electric aircraft. An example of a vertical take-off and landing aircraft is the eVTOL. eVTOL is an abbreviation for electric vertical take-off and landing aircraft.

[0012] The drive system 30 is a system that drives a moving object. If the moving object is a vehicle, the drive system 30 drives the vehicle to move; if the moving object is an aircraft, the drive system 30 drives the aircraft to fly.

[0013] The drive system 30 includes a battery 31 and an EPU 50. The battery 31 is electrically connected to the EPU 50. The battery 31 is a power supply unit that supplies power to the EPU 50 and corresponds to a power supply unit. The battery 31 is a DC voltage source that applies a DC voltage to the EPU 50. The battery 31 is a rechargeable secondary battery. This secondary battery may be a lithium-ion battery, a nickel-metal hydride battery, etc. In addition to or instead of the battery 31, a fuel cell or a generator may be used as the power supply unit.

[0014] The EPU50 is a device that drives a moving object, and is a rotating electric machine unit consisting of a motor electromagnetic circuit 61 and an inverter device 80. When mounted on a vehicle, the EPU50 drives and rotates, for example, the wheels. When mounted on an aircraft, the EPU50 drives and rotates, for example, the rotor blades. This EPU50 is sometimes referred to as an electric drive device, or a propulsion device that propels an aircraft.

[0015] The EPU50 has a motor unit 60 (see Figure 2) and an inverter unit 80. For example, the EPU50 has one motor unit 60 and one inverter unit 80. The motor unit 60 has a motor electromagnetic circuit 61. The inverter unit 80 has an inverter main circuit 81 composed of multiple switch elements. The motor unit 60 corresponds to a rotating electric machine, and the inverter unit 80 corresponds to a power converter. The battery 31 is electrically connected to the motor electromagnetic circuit 61 via the inverter main circuit 81. Power is supplied to the motor electromagnetic circuit 61 from the battery 31 according to the voltage and current supplied from the inverter main circuit 81.

[0016] The motor electromagnetic circuit 61 is a multi-phase AC motor. For example, the motor electromagnetic circuit 61 is a three-phase AC motor, and a brushless motor having U-phase, V-phase, and W-phase is used. The motor electromagnetic circuit 61 functions as a generator during regeneration. The coils of the motor electromagnetic circuit 61 are usually three-phase, consisting of U-phase, V-phase, and W-phase, but the number of phases and connection method are not limited.

[0017] The inverter main circuit 81 converts the power supplied to the motor electromagnetic circuit 61 from DC to AC using a high-speed switch. The inverter main circuit 81 is a power conversion unit that converts power. The inverter main circuit 81 performs power conversion for each of the multiple phases.

[0018] The inverter device 80 has a P line 141 and an N line 142. The P line 141 and the N line 142 electrically connect the battery 31 and the inverter main circuit 81. The P line 141 is electrically connected to the positive terminal of the battery 31. The N line 142 is electrically connected to the negative terminal of the battery 31. The battery 31 has the function of supplying or charging power.

[0019] The inverter device 80 includes a smoothing capacitor 145 and an EMI filter 150 in addition to the inverter main circuit 81. The smoothing capacitor 145 consists of multiple capacitors connected in parallel and is connected to the P line 141 and the N line 142. The smoothing capacitor 145 smooths the current ripple that flows when the inverter main circuit 81 operates intermittently, and stabilizes the current supplied from the battery 31.

[0020] The EMI filter 150 is a filter circuit that reduces electromagnetic noise generated from the EPU 50 between the battery 31 and the inverter main circuit 81. The EMI filter 150 is connected to the P line 141, the N line 142, and the EPU's ground. The EMI filter 150 may be omitted in EPU systems where the case and wiring are adequately shielded.

[0021] The EMI filter 150 includes components such as a common mode coil 151, a normal mode coil 152, a Y capacitor 153, an X capacitor 154, and a varistor 155. In the EMI filter 150, the number of stages, circuit configuration, and component values ​​of the common mode coil 151, normal mode coil 152, Y capacitor 153, and X capacitor 154 are designed to meet the required EMI standards. The varistor 155 absorbs external surges such as lightning surges, protecting the electronic components and electrical equipment in the EPU 50 from surges.

[0022] If we refer to the pair of the upper arm 84 and the lower arm 85 as one phase leg, the inverter main circuit 81 configures circuits corresponding to the number of motor phases, such as U-phase, V-phase, and W-phase, by connecting multiple legs in parallel. The high-potential side of the upper arm 84 is connected to the P line 141, and the low-potential side of the lower arm 85 is connected to the N line 142. Furthermore, the low-potential side of the upper arm 84 and the high-potential side of the lower arm 85 of each leg are connected and connected to the output line 143.

[0023] The upper arm 84 and lower arm 85 have an arm switch 86 that can select and switch between a conductive and non-conductive state, and a diode 87 that can allow current to flow from the low potential side to the high potential side even in the non-conductive state. The arm switch 86 is a transistor such as a MOSFET or RC-IGBT. The arm switch 86 is composed of a single component that combines the arm switch 86 and the diode 87. The arm switch 86 is sometimes referred to as a transistor switch.

[0024] The upper arm 84 and the lower arm 85 each consist of at least one arm switch 86 and one diode 87. In the upper arm 84 and the lower arm 85, multiple elements may be connected in parallel. Figures 1 and 11 show three parallel connections as an example. Figure 5 and others show six parallel connections as an example.

[0025] The inverter device 80 has a drive circuit 160 and a control circuit 161. In Figure 1, the drive circuit 160 is shown as DD and the control circuit 161 as CD.

[0026] The control circuit 161 is a control device such as an ECU, and controls the switch elements of the inverter main circuit 81. ECU is an abbreviation for Electronic Control Unit. The control circuit 161 is mainly composed of a microcomputer circuit that includes, for example, a processor, memory, I / O, power supply circuit, and wiring to connect them.

[0027] The control circuit 161 determines the conduction state of the arm switch 86 of the inverter main circuit 81 by executing a control program stored in memory. The control circuit 161 is also electrically connected to external devices and various sensors. External devices include, for example, higher-level ECUs such as integrated ECUs mounted on mobile bodies. External devices command the drive torque and rotational speed of the EPU 50 and monitor the status of the EPU 50. Various sensors are signal sources required by the control program, such as temperature, current, voltage, angle, and speed of various parts.

[0028] The drive circuit 160 is electrically connected to each of the multiple arm switches 86 of the inverter main circuit 81. The drive circuit 160 drives the gates of the arm switches 86 to a conductive state and a non-conductive state using functions of isolation, level conversion, and amplification of command signals from the control circuit 161. The drive circuit 160 is sometimes referred to as a driver. The conductive state is sometimes referred to as the on state, and the non-conductive state is sometimes referred to as the off state.

[0029] Examples of various sensors built into the inverter device 80 include a motor current sensor 146 and a battery current sensor 147. The motor current sensor 146 is electrically connected to the control circuit 161 and is installed, for example, for each of the U, V, and W phases to detect the current flowing through the output line 143. The battery current sensor 147 is installed, for example, on the P line 141 and is electrically connected to the control circuit 161 to detect the current flowing through the battery 31.

[0030] As shown in Figures 2, 3, and 4, in the EPU 50, the inverter device 80 is arranged along the motor axis Cm of the motor device 60, overlapped in the axial direction AD, and fixed to each other by fasteners such as bolts. The motor device 60 and the inverter device 80 are each formed in a cylindrical shape as a whole. Hereinafter, the directions in the cylindrical shape will be described as the mutually orthogonal axial direction AD, radial direction RD, and circumferential direction CD.

[0031] The motor device 60 has at least one stator 200 and at least one rotor 300 that rotates around the motor axis Cm, which constitute the motor electromagnetic circuit 61. The motor device 60 is, for example, an axial gap type motor and is arranged in the axial direction A and D. For example, the stator 200 is provided between two rotors 300.

[0032] In Figure 3, the motor housing 70 is, for example, cylindrical and houses the motor device 60. The motor housing 70 is made of a metal material or the like and has thermal conductivity.

[0033] The motor housing 70 has a motor outer circumferential wall 71 and motor fins 72. The motor outer circumferential wall 71 is annular in the circumferential direction CD and has an outer circumferential surface 70a for cooling the motor device 60. The motor fins 72 are cooling fins provided on the outer circumferential surface 70a to enhance the heat dissipation effect, and protrude radially outward to increase the surface area, extending in the axial direction AD. Multiple motor fins 72 are arranged in the circumferential direction CD.

[0034] The inverter housing 90 is, for example, cylindrical and houses the inverter device 80, including the inverter main circuit 81. The inverter axis Ci is the centerline of the inverter housing 90 and coincides with the motor axis Cm. The inverter housing 90 is made of a metal material or the like and has thermal conductivity. The inverter housing 90 has an inverter outer wall 91 and inverter fins 92.

[0035] The inverter outer circumferential wall 91 is annular in the circumferential direction CD and has an outer circumferential surface 90a and an inner circumferential surface 90b (see Figure 5) mainly for cooling the inverter main circuit 81. The inverter fins 92 are heat dissipation fins provided on the outer circumferential surface 90a to enhance the heat dissipation effect, and protrude radially outward to increase the surface area, extending in the axial direction AD. Multiple inverter fins 92 are arranged in the circumferential direction CD.

[0036] If the motor outer wall 71 and the inverter outer wall 91 have the same shape and size in a plan view along the axial direction AD, then fixing the motor unit 60 and the inverter unit 80 along the axial direction AD makes it easier to efficiently direct cooling air along the axial direction AD. However, if it is possible to fix the motor unit 60 and the inverter unit 80 along the axial direction AD, the motor outer wall 71 and the inverter outer wall 91 may have different shapes and sizes in a plan view.

[0037] As described above, in the case of air cooling, the EPU 50 is cooled by airflow from a blower fan along the plate surfaces of the motor fins 72 and inverter fins 92 in the axial direction AD, thereby achieving cooling of the motor unit 60 and inverter unit 80.

[0038] As shown in Figure 2, the EPU 50 has a unit duct 100 that is formed in a cylindrical shape overall in order to efficiently direct the cooling air from the blower fan in the axial direction AD along the plate surfaces of the motor fins 72 and inverter fins 92. The unit duct 100 covers the motor housing 70 and inverter housing 90 from the outer periphery, and has openings formed at both ends in the axial direction AD.

[0039] A further advantageous configuration is one in which the inner circumferential surface of the unit duct 100 approaches or contacts the tip surfaces of the motor fins 72 and inverter fins 92. In this configuration, most of the cooling air passing in the axial direction AD passes between the motor fins 72 and inverter fins 92, thereby enhancing the heat dissipation effect.

[0040] As shown in Figure 4, the motor device 60 includes a shaft 340, a first bearing 360, a second bearing 361, and a rotation angle resolver 421. The shaft 340 is a rotating shaft that rotates together with the rotor 300.

[0041] The first bearing 360 and the second bearing 361 are arranged in the axial direction AD and support the rotor 300 and shaft 340, making them rotatable. The first bearing 360 is located on the inverter device 80 side of the second bearing 361 in the axial direction AD. The first bearing 360 is located, for example, inside the inverter device 80. At least a portion of the first bearing 360 is housed in the inverter housing 90. The first bearing 360 is fixed to an end plate fixed to the motor housing 70 or to an end plate sandwiched between the inverter housing 90 and the motor housing 70.

[0042] The rotation angle resolver 421 is a sensor that detects the rotation angle of the motor electromagnetic circuit 61. The rotation angle resolver 421 is electrically connected to the control circuit 161 and outputs a SIN / COS detection signal in response to the excitation signal from the control circuit 161. The control circuit 161 measures the rotation angle and rotation speed from the SIN / COS detection signal. The control circuit 161 may also detect rotation from other sensors. The control circuit 161 may also estimate the rotation angle using methods that do not use a rotation angle sensor, such as motor current.

[0043] The rotation angle resolver 421 is located, for example, inside the inverter device 80. The rotation angle resolver 421 is located, for example, on the inverter device 80 side of the first bearing 360 in the axial direction AD.

[0044] In the motor housing 70, the stator 200 and rotor 300 are housed in the internal space of the motor outer wall 71. The motor outer wall 71 is aligned with the inverter outer wall 91 in the axial direction A and D. The inverter outer wall 91 corresponds to the device outer wall, and the motor outer wall 71 corresponds to the electrical outer wall.

[0045] The motor device 60 has a rear end plate 62 and a front end plate 63 in addition to the motor housing 70. The end plates 62 and 63 are made of a metal or the like and have thermal conductivity. The end plates 62 and 63 extend in a plate shape in a direction perpendicular to the axial direction AD. The end plates 62 and 63 are arranged in the axial direction AD via the motor housing 70. The end plates 62 and 63 are fixed to the motor outer circumferential wall 71, covering the internal space of the motor outer circumferential wall 71.

[0046] The rear end plate 62 is provided between the motor housing 70 and the inverter housing 90. The rear end plate 62 is sandwiched, for example, between the outer peripheral wall 71 of the motor and the outer peripheral wall 91 of the inverter. The rear end plate 62 covers the stator 200 and rotor 300 from the inverter device 80 side. The rear end plate 62 is formed in an annular shape and is provided radially outward of the first bearing 360. The rear end plate 62 corresponds to a cover portion.

[0047] The inverter device 80 has an insulating section 545. The insulating section 545 has thermal insulation properties and consists of an insulating layer and an air layer. The insulating layer is formed of a material that has thermal insulation properties. The insulating section 545 extends in a plate shape in a direction perpendicular to the axial direction AD. The insulating section 545 is provided between the rear end plate 62 and the high-voltage substrate 510 in the axial direction AD. The insulating section 545 extends along the rear end plate 62. The insulating section 545 is provided on the opposite side of the rear end plate 62, for example, via a rotation angle resolver 421.

[0048] A reduction gear 53 is attached to the EPU 50. The reduction gear 53 mechanically connects the motor electromagnetic circuit 61 to external equipment. For example, the external equipment is mechanically connected to the rotating shaft of the motor electromagnetic circuit 61 via the reduction gear 53. The reduction gear 53 reduces the rotation of the motor electromagnetic circuit 61 and transmits it to the external equipment. Examples of external equipment include wheels and rotor blades. The reduction gear 53 is composed of multiple gears and is sometimes referred to as a reduction gear. The reduction gear 53 is structured to match the motor characteristics of the motor electromagnetic circuit 61. For example, the reduction gear 53 is located on the opposite side of the inverter device 80 via the motor device 60 in the axial direction AD.

[0049] <Composition group A> As shown in Figure 4, the inverter device 80 has an inverter cover 99 in addition to the inverter housing 90. The inverter cover 99 is made of a metal material or the like, has thermal conductivity, and is capable of releasing heat from inside the inverter device 80 to the outside. The inverter cover 99 closes the opening of the inverter housing 90 and prevents foreign matter from entering the inverter. The inverter cover 99 is located on the side opposite to the motor device 60 via the inverter housing 90 in the axial direction AD. The inverter cover 99 has a shape that bulges outwards in the axial direction AD away from the motor device 60. The inverter cover 99 has a flat plate portion extending in a direction perpendicular to the motor axis Cm, and an annular wall portion extending in an annular shape along the outer edge of the flat plate portion. The inverter cover 99 also has the function of sealing the gap with the inverter housing 90, the function of coupling with the inverter housing 90, and the function of reducing electromagnetic radiation or intrusion.

[0050] The inverter device 80 includes a high-voltage board 510, a drive board 550, and a control board 560. The high-voltage board 510 is a circuit board on which the inverter main circuit 81, a smoothing capacitor 145, and an EMI filter 150 are mounted. The drive board 550 is a circuit board on which the drive circuit 160 is mounted. The control board 560 is a circuit board on which the control circuit 161 is mounted.

[0051] The drive board 550 and the control board 560 are low-voltage boards to which a low voltage is applied. The low voltage is the voltage used to drive the drive circuit 160 and the control circuit 161. In the inverter device 80, the voltage applied to the drive circuit 160 and the control circuit 161 is a low voltage. Boards 510, 550, and 560 are sometimes referred to as electrical wiring boards and circuit boards.

[0052] As shown in Figures 5 and 6, the high-voltage substrate 510, the drive substrate 550, and the control substrate 560 have inner circumferential ends 511, 551, 561 and outer circumferential ends 512, 552, 562. The control substrate 560 may not have an inner circumferential end 561. The drive substrate 550 and the control substrate 560 may be integrated. In the high-voltage substrate 510 and the drive substrate 550, the outer circumferential ends 512, 552 are located radially inward from the inner circumferential surface 90b of the inverter outer circumferential wall 91, forming a gap.

[0053] As shown in Figure 5, the inverter device 80 has an inverter fin group 93 formed by arranging a plurality of inverter fins 92 in the circumferential direction CD. The inverter fin group 93 is contained within the inverter housing 90.

[0054] The flanges 94 and 95 are protrusions provided on the outer circumferential surface 90a, projecting radially outward from the inverter outer circumferential wall 91. The flanges 94 and 95 are provided between two adjacent inverter fin groups 93 in the circumferential direction CD. The high-pressure side flange 94 and the low-pressure side flange 95 are aligned in the axial direction AD. For example, the motor housing 70 is fixed to the high-pressure side flange 94 by fasteners such as bolts. For example, the inverter cover 99 is fixed to the low-pressure side flange 95 by fasteners.

[0055] The inverter housing 90 and the motor housing 70 have cylindrical interiors, and an O-ring 98 is sandwiched between them and an inner cylinder (not shown). The O-ring 98 seals the joint between the inverter housing 90 and the motor housing 70.

[0056] The inverter device 80 has a smoothing capacitor section 580 and a filter component 524. The smoothing capacitor section 580 and the filter component 524 are mounted on a high-voltage substrate 510 and are mechanically and electrically connected. The smoothing capacitor section 580 is made up of multiple smoothing capacitors 145 as shown in Figure 1, mounted in a distributed manner.

[0057] The filter components 524 include a common mode coil section 525, a normal mode coil section 526, a Y capacitor section 527, and an X capacitor section 528. The common mode coil section 525 has a common mode coil 151. The normal mode coil section 526 has a normal mode coil 152. The Y capacitor section 527 has a Y capacitor 153. The X capacitor section 528 has an X capacitor 154.

[0058] Multiple motor current sensors 146 are provided to correspond to the U-phase, V-phase, and W-phase. Battery current sensors 147 are provided on either or both of the P-line 141 or N-line 142. Current sensors 146 and 147 are provided on the high-voltage circuit board 510.

[0059] The inverter device 80 has an arm switch section 530. The arm switch section 530 has the functions of an arm switch 86 and a diode 87 of the inverter main circuit 81. Multiple arm switch sections 530 are arranged and fixed in a circumferential direction CD along the inner circumferential surface 90b of the inverter housing 90. Multiple arm switch sections 530 are arranged along the outer circumferential edges 512, 552 of the high-voltage substrate 510 and the control substrate 560.

[0060] The inverter device 80 has a fan device 540. The fan device 540 cools the high-temperature parts inside the inverter device 80 by circulating the air inside. The fan device 540 is an electric fan or a fan that rotates on a motor shaft.

[0061] As shown in Figure 7, the fan device 540 is positioned in the axial direction AD in line with the substrate openings 513, 553, and 563. To promote air circulation between each substrate, the substrate openings 513, 553, and 563 may be shaped to partially obstruct the airflow from the fan device 540. The air that passes through the substrate openings 513, 553, and 563 passes between the substrates 510, 550, and 560 and the inverter cover 99, between the outer shape and the inner surface of the case, and returns to the fan from between the components mounted on the high-voltage substrate 510. The circulation path may also be reversed.

[0062] As shown in Figures 7 to 9, the inverter housing 90 has a component support portion 500 on the inner diameter side of the inverter outer circumferential wall 91. The component support portion 500 is composed of a plurality of beam portions 501 along the inner circumferential surface 90b in the circumferential direction CD. The beam portions 501 are provided between the high-pressure side flange 94 and the low-pressure side flange 95 in the axial direction AD, in a portion that does not interfere with the arm switch portion 530 of the inverter outer circumferential wall 91. The inverter fin group 93 is located between two adjacent beam portions 501 in the circumferential direction CD. The plurality of beam portions 501 are arranged to extend radially from the inner circumferential surface 90b toward the center in the radial direction RD, or radially outward from the inverter axis Ci. The inverter housing 90 has a beam connecting portion 502 that connects the plurality of beam portions 501 toward the center. The beam connecting portion 502 is provided with one or more connecting openings 504. The beam portions 501 extend in a frame-like manner in the radial direction RD and are sometimes referred to as support frames. The inverter outer wall 91 corresponds to the outer wall, and the inverter housing 90 corresponds to the case.

[0063] The component support section 500 has substrates 510, 550, and 560 arranged in the axial direction AD. The component support section 500 is provided between the high-voltage substrate 510 and the drive substrate 550 in the axial direction AD. The component support section 500, the high-voltage substrate 510, and the control substrate 560 form a sandwich structure via multiple beam sections 501, thereby achieving a lightweight yet strong structure.

[0064] The inverter housing 90 is made of a material that has thermal conductivity and electrical conductivity. Therefore, the inverter housing 90 has a heat dissipation path and an electrical conduction path.

[0065] The heat dissipation path is formed by, for example, the inverter outer periphery wall 91, the inverter fins 92, and the component support section 500. In the heat dissipation path, for example, heat from the component support section 500 is released to the outside through the inverter outer periphery wall 91 and the inverter fins 92.

[0066] The conductive path is a grounding path, which is either ground or earth. The inverter housing 90 is formed including the inverter outer wall 91, the high-voltage side flange 94, the low-voltage side flange 95, and the component support portion 500, and connects the ground of the Y capacitor portion 527 and the circuit boards 510, 550, 560, etc. to a low impedance. The motor housing 70 and the inverter cover portion 99 form a grounding path via the flanges 94 and 95.

[0067] In the component support section 500, a fan device 540 can be mounted on the beam connection section 502 to promote internal cooling of the inverter. A beam opening 503 can be provided in the beam section 501. The beam opening 503 is an opening provided for bolting components mounted on the high-voltage substrate 510 from the beam section 501 side. For example, the beam opening 503 is an opening for bolting busbars or studs for passing current from the high-voltage substrate 510 to a plurality of motor current sensors 146.

[0068] As shown in Figure 8, the beam portion 501 and beam connecting portion 502 of the component support portion 500 have screw holes 505 for fixing the high-voltage substrate 510. In addition, as shown in Figure 9, the beam portion 501 and beam connecting portion 502 have multiple screw holes 506 for fixing the drive substrate 550 and the control substrate 560. The multiple screw holes 505 include screw holes 505a for fixing only the substrate, screw holes 505b for fixing, for example, the current sensor and the substrate together, and screw holes 505c for fixing, for example, only the fan device 540.

[0069] The high-voltage substrate 510 and the drive substrate 550 correspond to plate members. The high-voltage substrate 510 corresponds to the first plate member, and the drive substrate 550 corresponds to the second plate member.

[0070] As shown in Figures 5 and 6, the inverter device 80 has a switch group 530G consisting of a plurality of arm switch units 530. The switch group 530G is arranged in a line in the circumferential direction CD such that the plurality of arm switch units 530 are densely packed together. Multiple switch groups 530G are arranged in the circumferential direction CD along the inner circumferential surface 90b. The inner circumferential surface 90b is polygonal, and it is also possible to arrange multiple switch groups 530G on the same plane. Multiple switch groups 530G are arranged along the outer circumferential edges 512, 552 with respect to the high-voltage substrate 510 and the drive substrate 550.

[0071] The switch group 530G consists of multiple arm switch units 530 connected in parallel, corresponding to the upper arm 84 and lower arm 85 of the inverter main circuit 81 in the circuit diagram. For example, if one upper arm 84 in the circuit diagram has six arm switches 86, then the switch group 530G in the embodiment corresponding to this upper arm 84 will have six arm switch units 530. Similarly, one lower arm 85 in the circuit diagram will also form a switch group 530G having six arm switch units 530.

[0072] For example, two adjacent switch groups 530G in the circumferential direction CD are arranged such that an upper arm 84 and a lower arm 85 form a pair that constitutes one phase. A point for extracting motor current is provided on the high-voltage substrate 510 near the midpoint of these switch groups 530G. Of the arms 84 and 85 of one upper and lower arm circuit 83, the switch group 530G corresponding to the upper arm 84 and the switch group 530G corresponding to the lower arm 85 are two adjacent switch groups 530G in the circumferential direction CD.

[0073] As shown in Figures 8 and 9, the switch group 530G is provided between two adjacent beams 501 along the circumferential direction CD of the inner circumferential surface 90b of the inverter outer circumferential wall 91. The switch group 530G is located between two adjacent flanges 94 and 95 in the circumferential direction CD. The switch group 530G is located in a position that overlaps with the inverter fin group 93 in the axial direction AD. The switch group 530G and the inverter fin group 93 are aligned in the axial direction AD via the inverter outer circumferential wall 91.

[0074] As shown in Figure 10, the arm switch section 530 has a switch body 531. The switch body 531 is provided on the inner circumferential surface 90b, which is a cooling surface, and is fixed to the inner circumferential surface 90b, for example. The switch body 531 has elements such as a MOSFET and a protective section. The switch body 531 has a first plate surface 531a and a second plate surface 531b. The first plate surface 531a and the second plate surface 531b extend in a direction perpendicular to the radial direction RD.

[0075] The arm switch section 530 has four terminals, terminals 532 to 535, and is a four-terminal type switch module. Terminals 532 to 535 are the drain terminal 532, source terminal 533, gate terminal 534, and driver source terminal 535. The driver source terminal 535 is sometimes called the Kelvin source terminal. Terminals 532 to 535 correspond to the switch terminals.

[0076] The drain terminal 532 and source terminal 533 are power terminals and are connected to the high-voltage board 510. The gate terminal 534 and driver source terminal 535 are control terminals and are connected to the control board 560. Terminals 532 to 535 extend from the switch body 531. Terminals 532 to 535 are arranged in the width direction of the switch body 531.

[0077] The switch body 531 is located spaced apart from the outer peripheral end faces of the substrates 510, 550, and 560. The switch body 531 is located spaced apart from the beam portion 501 in the axial direction AD. The drain terminal 532 and source terminal 533 are connected between the switch body 531 and the high-voltage substrate 510 on the high-voltage side of the beam portion 501. The gate terminal 534 and driver source terminal 535 are connected between the switch body 531 and the drive substrate 550, extending axially AD through the beam portion 501.

[0078] As shown in Figure 5, the inverter device 80 has an inverter connector 96 and power lines 570 and 571. The inverter connector 96 connects the inverter device 80 to an external battery 31, etc. The inverter connector 96 is designed to accept power cables. The inverter connector 96 protrudes radially outward from the inverter housing 90. A configuration without the inverter connector 96, where the power lines 570 and 571 extend to the outside, is also possible.

[0079] Power lines 570 and 571 are electrically connected to the high-voltage circuit board 510. Power lines 570 and 571 are connected from the high-voltage circuit board 510 through the filter component 524 to the arm switch section 530 and the smoothing capacitor section 580. Power line 570 is an electrical wiring that forms the P line 141. Power line 571 is an electrical wiring that forms the N line 142. A battery current sensor 147 is provided for either or both of power lines 570 and 571. A motor current sensor 146 is provided on a busbar drawn from the high-voltage circuit board 510. This busbar is connected to the motor.

[0080] <Composition group B> In Figures 4 to 6, substrates 510, 550, and 560 have insulating substrates and wiring patterns. The insulating substrates are electrically insulating and are formed in a plate shape from a resin material or the like. The wiring patterns are conductive and are formed from conductive materials such as copper and aluminum.

[0081] The high-voltage substrate 510, the drive substrate 550, and the control substrate 560 are all formed in a plate shape and extend in a direction perpendicular to the axial direction AD. The substrates 510, 550, and 560 extend in an annular shape around the inverter axis Ci. The substrates 510, 550, and 560 are formed as a whole in a disc shape. The substrates 510, 550, and 560 are arranged in the axial direction AD with their respective plate surfaces facing each other. In the axial direction AD, the drive substrate 550 is provided between the high-voltage substrate 510 and the control substrate 560. In the inverter device 80, the side with the high-voltage substrate 510 is referred to as the high-voltage side, and the side with the drive substrate 550 is referred to as the low-voltage side in the axial direction AD. The motor device 60 is provided, for example, on the high-voltage side of the inverter device 80.

[0082] As shown in Figure 11, the high-voltage substrate 510 has a P busbar 601, an N busbar 602, an output busbar 603, and an earth busbar 604. Busbars 601 to 604 are included in the wiring pattern of the high-voltage substrate 510. Busbars 601 to 604 are formed in a plate shape and extend in a direction perpendicular to the axial direction AD. Busbars 601 to 604 are conductive conductors and correspond to plate-shaped conductors. Busbars 601 to 604 as a whole extend in the circumferential direction CD. The circumferential direction CD corresponds to the direction of extension. Busbars 601 to 604 are provided inside the high-voltage substrate 510. In the high-voltage substrate 510, for example, busbars 601 to 604 and a plurality of insulating substrates are alternately stacked. Busbars 601 to 604 are sometimes referred to as substrate conductors. The high-voltage substrate 510 corresponds to a power substrate.

[0083] In Figure 12, the P busbar 601 forms at least a portion of the P line 141. The P busbar 601 corresponds to a high-potential conductor and a power conductor, and is sometimes referred to as a high-potential busbar and a power busbar. The P busbar 601 has an outer circumference P busbar 601a and an inner circumference P busbar 601b. The P busbars 601a and 601b are conductive members such as busbar members formed of a conductive material. The P busbars 601a and 601b extend in an annular shape around the inverter axis Ci, similar to the high-voltage substrate 510. The P busbars 601a and 601b are formed in a disc shape as a whole. The outer circumference P busbar 601a and the inner circumference P busbar 601b are arranged in the radial direction RD. The outer circumference P busbar 601a is provided radially outward from the inner circumference P busbar 601b.

[0084] The outer peripheral P busbar 601a extends along the outer peripheral edge 512 of the high-voltage substrate 510. The outer peripheral P busbar 601a is provided in the smoothing capacitor section 580 at a position aligned with the axial direction A and D. The outer peripheral P busbar 601a extends in the circumferential direction CD along the capacitor row 580R. The smoothing capacitor section 580 may be provided at a position that protrudes radially outward and radially inward from the outer peripheral P busbar 601a, or it may be provided at a position that does not protrude.

[0085] The inner circumference P busbar 601b extends along the inner circumference end 511 on the high-voltage substrate 510. The inner circumference P busbar 601b is positioned on the filter component 524 in the axial direction AD. The inner circumference P busbar 601b extends circumferentially CD along the filter row 524R. The filter component 524 may be positioned to protrude radially outward and radially inward from the inner circumference P busbar 601b in at least one direction, or it may be positioned not to protrude.

[0086] The outer P busbar 601a and the inner P busbar 601b are connected to the power line 570 so that power can be transmitted via electrical wiring or the like. The P busbar 601 may have three or more busbar members such as P busbars 601a and 601b, or it may have only one busbar member.

[0087] The N busbar 602 forms at least a portion of the N line 142. The N busbar 602 corresponds to a low-potential conductor and a power conductor, and is sometimes referred to as a low-potential busbar and a power busbar. The N busbar 602 has an outer circumference N busbar 602a and an inner circumference N busbar 602b. The N busbars 602a and 602b are conductive members such as busbar members formed of a conductive material. The N busbars 602a and 602b extend in an annular shape around the inverter axis Ci, similar to the high-voltage substrate 510. The N busbars 602a and 602b are formed in a disc shape as a whole. The outer circumference N busbar 602a and the inner circumference N busbar 602b are arranged in the radial direction RD. The outer circumference N busbar 602a is provided radially outward from the inner circumference N busbar 602b.

[0088] The outer peripheral N busbar 602a extends along the outer peripheral edge 512 of the high-voltage substrate 510. The outer peripheral N busbar 602a is provided in the smoothing capacitor section 580 at a position aligned with the axial direction A and D. The outer peripheral N busbar 602a extends in the circumferential direction CD along the capacitor row 580R. The smoothing capacitor section 580 may be provided at a position that protrudes radially outward and radially inward from the outer peripheral N busbar 602a, or it may be provided at a position that does not protrude.

[0089] The inner circumference N busbar 602b extends along the inner circumference end 511 on the high-voltage substrate 510. The inner circumference N busbar 602b is positioned on the filter component 524 in the axial direction A and D. The inner circumference N busbar 602b extends in the circumferential direction CD along the filter row 524R. The filter component 524 may be positioned to protrude radially outward and radially inward from the inner circumference N busbar 602b in at least one direction, or it may be positioned not to protrude.

[0090] The outer N busbar 602a and the inner N busbar 602b are connected to the power line 571 so that power can be transmitted via electrical wiring or the like. The N busbar 602 may have three or more busbar members such as N busbars 602a and 602b, or it may have only one busbar member.

[0091] In Figure 13, the output busbar 603 forms at least a portion of the output line 143. The output busbar 603 corresponds to the output conductor. The output busbar 603 is a conductive member, such as a busbar member, made of a conductive material. The output busbar 603 is formed in a plate shape so as to be curved in the circumferential direction CD. Multiple output busbars 603 are arranged along the outer peripheral end 512 in the circumferential direction CD. Two adjacent output busbars 603 in the circumferential direction CD are spaced apart in the circumferential direction CD.

[0092] The output busbar 603 extends along the outer peripheral edge 512 of the high-voltage substrate 510. The output busbar 603 is provided in the smoothing capacitor section 580 at a position aligned with the axial direction AD. The output busbar 603 extends in the circumferential direction CD along the capacitor row 580R. The smoothing capacitor section 580 may be provided at a position that protrudes radially outward and radially inward from the output busbar 603, or it may be provided at a position that does not protrude. The output busbar 603 is provided radially outward from the filter component 524. The output busbar 603 may also be provided at a position aligned with the filter component 524 in the axial direction AD. Furthermore, the output busbar 603 may be provided at a position that spans the outer peripheral P busbar 601a and the inner peripheral P busbar 601b in the radial direction RD.

[0093] The output busbars 603 are provided to correspond to each of the multiple phases. The multiple output busbars 603 include output busbars 603 corresponding to the U phase, V phase, and W phase, respectively. For example, the U phase output busbar 603 is connected to the U phase coil of the motor electromagnetic circuit 61 so as to be energized.

[0094] The high-voltage circuit board 510 has an output connection section 514. The output connection section 514 is energetically connected to the output busbar 603. An output connection section 514 is provided individually for each of the multiple output busbars 603. An output cable, such as electrical wiring, is connected to the output connection section 514. This output cable and the output connection section 514 together with the output busbar 603 form an output line 143. A current sensor 147 is provided for at least one of the output cable and the output connection section 514. The output connection section 514 is provided, for example, between two adjacent switch groups 530G in the circumferential direction CD.

[0095] In Figure 14, the earth busbar 604 forms at least a part of the grounding path. The earth busbar 604 corresponds to a grounding conductor and is sometimes referred to as an earth conductor. The earth busbar 604 is a busbar member formed of a conductive material. The earth busbar 604 is connected to case ground. The earth busbar 604 is connected to the inverter housing 90 so as to be conductive to ground GND. For example, the fastener that fixes the high-voltage substrate 510 to the component support part 500 is screwed through the earth busbar 604 into the screw hole 505. The earth busbar 604 is electrically connected to the component support part 500 via this fastener. Since multiple such fasteners are provided, the earth busbar 604 and the component support part 500 are electrically connected at multiple points.

[0096] The earth busbar 604, like the P busbar 601 and N busbar 602, extends in an annular shape around the inverter axis Ci. The earth busbar 604 is formed in a disc shape overall. The earth busbar 604 extends radially RD so as to span the inner circumference end 511 and the outer circumference end 512. For example, the earth busbar 604 is spanned radially RD between the outer circumference P busbar 601a and the inner circumference P busbar 601b.

[0097] The earth busbar 604 is provided in both the smoothing capacitor section 580 and the filter component 524, aligned in the axial direction AD. The earth busbar 604 extends circumferentially CD along both the capacitor row 580R and the filter row 524R. The smoothing capacitor section 580 may be provided in a position that extends radially outward from the earth busbar 604, or it may be provided in a position that does not extend there. The filter component 524 may be provided in a position that extends radially inward from the earth busbar 604, or it may be provided in a position that does not extend there.

[0098] As shown in Figure 11, the high-voltage substrate 510 has multiple plate-shaped conductors such as busbars 601 to 604. In the high-voltage substrate 510, the busbars 601 to 604 are included in the multiple plate-shaped conductors. Each of the multiple plate-shaped conductors contains multiple busbars 601 to 604. Each of the multiple plate-shaped conductors contains, for example, two busbars 601 to 604. The multiple plate-shaped conductors are stacked in the axial direction AD. In the multiple plate-shaped conductors, an earth busbar 604 is provided at each of the pair of outermost positions. One of the pair of outermost positions is the position on the high-voltage side in the axial direction AD. The other outermost position is the position on the low-voltage side in the axial direction AD.

[0099] In the axial AD, multiple busbars 601 to 603 are provided between a pair of earth busbars 604. For example, two busbars 601 to 603 are provided between a pair of earth busbars 604. The output busbar 603 is provided between the P busbar 601 and the N busbar 602 in the axial AD. This output busbar 603 is located adjacent to both the P busbar 601 and the N busbar 602 in the axial AD. Of the P busbar 601 and N busbar 602 adjacent to the output busbar 603 in the axial AD, the P busbar 601 corresponds to the first plate portion, and the N busbar 602 corresponds to the second plate portion.

[0100] The high-voltage substrate 510 has a first busbar set 611 and a second busbar set 612. These busbar sets 611 and 612 each have one busbar 601 to 603. The busbar sets 611 and 612 are located between a pair of earth busbars 604 in the axial direction AD. The first busbar set 611 and the second busbar set 612 are superimposed in the axial direction AD. The first busbar set 611 is located on the high-voltage side of the second busbar set 612 in the axial direction AD. In both the first busbar set 611 and the second busbar set 612, an output busbar 603 is provided between the P busbar 601 and the N busbar 602. The arrangement of busbars 601 to 603 is the same in the first busbar set 611 and the second busbar set 612. For example, the busbars are arranged in the following order from the high-voltage side to the low-voltage side: P busbar 601, output busbar 603, and N busbar 602.

[0101] The smoothing capacitor section 580 has a capacitor body 581 and capacitor terminals 582 and 583. The capacitor body 581 is provided on the high-voltage substrate 510 and is fixed to the high-voltage substrate 510. The capacitor body 581 has elements and protective parts that form the smoothing capacitor 145. The capacitor body 581 is formed in a rectangular parallelepiped shape as a whole. The capacitor body 581 is provided on the first high-voltage surface 510a of the high-voltage substrate 510.

[0102] Capacitor terminals 582 and 583 are P-capacitor terminal 582 and N-capacitor terminal 583. P-capacitor terminal 582 is the terminal connected to P-busbar 601. N-capacitor terminal 583 is the terminal connected to N-busbar 602. Capacitor terminals 582 and 583 extend in the same direction from the capacitor body 581. Capacitor terminals 582 and 583 extend from one surface of the capacitor body 581 superimposed on the first high-voltage surface 510a toward the low-voltage side in the axial direction AD. P-capacitor terminal 582 corresponds to the high-capacitor terminal, and N-capacitor terminal 583 corresponds to the low-capacitor terminal.

[0103] As shown in Figure 15, the upper and lower arm circuit 83 has an upper arm switch 86A and a lower arm switch 86B. The upper arm switch 86A is an arm switch 86 included in the upper arm 84. The lower arm switch 86B is an arm switch 86 included in the lower arm 85.

[0104] As shown in Figures 15 and 16, the multiple arm switch sections 530 include an upper arm switch section 530A and a lower arm switch section 530B. The upper arm switch section 530A has an upper arm switch 86A and corresponds to the upper switch component on the high-potential side. The upper arm switch section 530A is energetically connected to the P busbar 601 and the output busbar 603. The lower arm switch section 530B has a lower arm switch 86B and corresponds to the lower switch component on the low-potential side. The lower arm switch section 530B is energetically connected to the output busbar 603 and the N busbar 602.

[0105] Multiple switch groups 530G include an upper switch group 530GA and a lower switch group 530GB. The upper switch group 530GA has multiple upper arm switch units 530A, but does not have a lower arm switch unit 530B. In the upper switch group 530GA, multiple upper arm switch units 530A are arranged in the circumferential direction CD. The lower switch group 530GB has multiple lower arm switch units 530B, but does not have an upper arm switch unit 530A. In the lower switch group 530GB, multiple lower arm switches 86B are arranged in the circumferential direction CD.

[0106] The upper arm switch section 530A and the lower arm switch section 530B, which constitute one upper and lower arm circuit 83, are included in the upper switch group 530GA and the lower switch group 530GB, which are adjacent to each other in the circumferential direction CD. These upper switch group 530GA and lower switch group 530GB are included in a single phase. For example, the upper switch group 530GA and the lower switch group 530GB of the U phase are located adjacent to each other in the circumferential direction CD.

[0107] Output connection sections 514 are provided for the upper switch group 530GA and the lower switch group 530GB, which are included in one phase. The output connection section 514 is provided between the upper switch group 530GA and the lower switch group 530GB, which are included in one phase, in the circumferential CD. The output connection section 514 is connected to the output busbar 603 between a plurality of upper source terminals 533A and a plurality of lower drain terminals 532B in the circumferential CD.

[0108] The smoothing capacitor section 580 is electrically connected in parallel to the upper arm switch section 530A and the lower arm switch section 530B. The smoothing capacitor section 580 is electrically connected to the P busbar 601 and the N busbar 602. The smoothing capacitor section 580 corresponds to a capacitor component and a parallel component.

[0109] As shown in Figures 12 to 14, the inverter device 80 has a capacitor group 580G. The capacitor group 580G has a plurality of smoothing capacitor sections 580. In the capacitor group 580G, the plurality of smoothing capacitor sections 580 are arranged in a line along the outer peripheral edge 512 in the circumferential direction CD so as to be densely packed. Multiple capacitor groups 580G are arranged along the outer peripheral edge 512 in the circumferential direction CD. The capacitor group 580G is arranged in the radial direction RD with the switch group 530G. For example, one capacitor group 580G and one switch group 530G are arranged in the radial direction RD.

[0110] As shown in Figure 16, the multiple smoothing capacitor sections 580 include an upper capacitor section 580A and a lower capacitor section 580B. The upper capacitor section 580A is located in a position aligned with the upper arm switch section 530A in the radial direction RD. The upper capacitor section 580A is located radially inward from the upper arm switch section 530A. The upper capacitor section 580A is located in a position aligned radially RD with the upper switch group 530GA, and is radially inward from the upper switch group 530GA. The upper capacitor section 580A corresponds to the upper capacitor component and the first capacitor component. The radial direction RD corresponds to the orthogonal direction perpendicular to the alignment direction.

[0111] The lower capacitor section 580B is located in a position aligned with the lower arm switch section 530B in the radial direction RD. The lower capacitor section 580B is located radially inward from the lower arm switch section 530B. The lower capacitor section 580B is located radially inward from the lower switch group 530GB, and is located radially inward from the lower switch group 530GB. The lower capacitor section 580B corresponds to the lower capacitor component and the second capacitor component.

[0112] The upper capacitor section 580A and the lower capacitor section 580B have opposite mounting orientations in the radial direction RD. In one of the upper capacitor section 580A and the lower capacitor section 580B, the P capacitor terminal 582 is located radially outward from the N capacitor terminal 583. In the other, the N capacitor terminal 583 is located radially outward from the P capacitor terminal 582. For example, in the upper capacitor section 580A, the P capacitor terminal 582 is located radially outward from the N capacitor terminal 583. In the lower capacitor section 580B, the N capacitor terminal 583 is located radially outward from the P capacitor terminal 582.

[0113] On the high-voltage substrate 510, the P capacitor terminal 582 of the upper capacitor section 580A and the N capacitor terminal 583 of the lower capacitor section 580B are aligned in the circumferential direction CD. Similarly, the N capacitor terminal 583 of the upper capacitor section 580A and the P capacitor terminal 582 of the lower capacitor section 580B are aligned in the circumferential direction CD.

[0114] Multiple capacitor groups 580G include an upper capacitor group 580GA and a lower capacitor group 580GB. The upper capacitor group 580GA has multiple upper capacitor sections 580A but no lower capacitor section 580B. The upper capacitor group 580GA is located radially RD aligned with the upper switch group 530GA and spaced radially inward from the upper switch group 530GA. The lower capacitor group 580GB has multiple lower capacitor sections 580B but no upper capacitor section 580A. The lower capacitor group 580GB is located radially RD aligned with the lower switch group 530GB and spaced radially inward from the lower switch group 530GB. The upper capacitor group 580GA corresponds to the first capacitor group, and the lower capacitor group 580GB corresponds to the second capacitor group.

[0115] As shown in Figure 15, in the inverter device 80, inductances L601 to L603 tend to occur as parasitic inductances that are parasitic to busbars 601 to 603. Inductances L601 to L603 can also be said to be parasitic to lines 141 to 143. Inductances L601 to L603 are P inductance L601, N inductance L602, and output inductance L603. P inductance L601 is the parasitic inductance that occurs in P busbar 601. N inductance L602 is the parasitic inductance that occurs in N busbar 602. Output inductance L603 is the parasitic inductance that occurs in output busbar 603.

[0116] If inductances L601 to L603 are parasitic on busbars 601 to 603, a voltage drop occurs across inductances L601 to L603. In this case, a potential difference is created in the arm switch section 530 equal to the voltage generated across inductances L601 to L603. For example, if inductance L601 is generated between two drain terminals 532 connected to P busbar 601, a potential difference is created between the two drain terminals 532 equal to the voltage generated across this inductance L601. Therefore, a potential difference is created between the two arm switch sections 530, each having these two drain terminals 532.

[0117] In Figure 15, for illustrative purposes, multiple inductors L601 to L603 are shown arranged along busbars 601 to 603. A Y capacitor 153 is connected to the earth busbar 604. There are two types of Y capacitors 153: one connected to the earth busbar 604 and the P busbar 601, and another connected to the earth busbar 604 and the N busbar 602. The Y capacitor section 527 is connected to the P busbar 601 or the N busbar 602 so as to be energizable, while also being connected to the earth busbar 604 so as to be conductive to ground GND.

[0118] In the inverter device 80, an inductance L580 is likely to occur as a parasitic inductance in the smoothing capacitor section 580. The inductance L580 occurs in the smoothing capacitor section 580. For example, the inductance L580 occurs in the current path connected to the smoothing capacitor 145 in the smoothing capacitor section 580. The inductance L580 occurs in the current path between the smoothing capacitor 145 and the P busbar 601, and between the smoothing capacitor 145 and the N busbar 602.

[0119] In the arm switch section 530, an inductance L530 is likely to occur as a parasitic inductance associated with the arm switch 86. The inductance L530 occurs in the arm switch section 530. The inductance L530 occurs, for example, in the current path connected to the arm switch 86 in the arm switch section 530. The inductance L530 occurs in the current path between the arm switch 86 and the P busbar 601 or N busbar 602, and between the arm switch 86 and the output busbar 603.

[0120] As shown in Figures 11 and 17, the high-voltage substrate 510 is provided with multiple through-holes 515. The arm switch section 530 and the smoothing capacitor section 580 are connected to the busbars 601 to 603 via the through-holes 515, allowing current to flow through them. In the arm switch section 530, the drain terminal 532 and the source terminal 533 are each inserted through the through-holes 515. These drain terminals 532 and source terminals 533 are connected to one of the busbars 601 to 603. In the smoothing capacitor section 580, the P capacitor terminal 582 and the N capacitor terminal 583 are each inserted through the through-holes 515. The P capacitor terminal 582 and the N capacitor terminal 583 are connected to either the P busbar 601 or the N busbar 602.

[0121] Multiple through-holes 515 include an upper switch hole 515a, a lower switch hole 515b, an upper capacitor hole 515c, and a lower capacitor hole 515d. Multiple switch holes 515a and 515b are arranged along the outer edge 512 of the high-voltage substrate 510. Terminals 532 and 533 of the upper arm switch section 530A are inserted through the upper switch hole 515a. The upper switch hole 515a is located in a position that overlaps with the upper arm switch section 530A in the axial direction AD. Terminals 532 and 533 of the lower arm switch section 530B are inserted through the lower switch hole 515b. The lower switch hole 515b is located in a position that overlaps with the lower arm switch section 530B in the axial direction AD.

[0122] Multiple capacitor holes 515c and 515d are arranged in the radial direction RD and multiple capacitor holes 515d are arranged in the circumferential direction CD. Capacitor terminals 582 and 583 of the smoothing capacitor section 580 are inserted through the upper capacitor hole 515c. The upper capacitor hole 515c is located in a position that overlaps with the upper capacitor section 580A in the axial direction AD. Capacitor terminals 582 and 583 of the smoothing capacitor section 580 are inserted through the lower capacitor hole 515d. The lower capacitor hole 515d is located in a position that overlaps with the lower capacitor section 580B in the axial direction AD.

[0123] As shown in Figure 17, in the upper arm switch section 530A, the upper drain terminal 532A and the upper source terminal 533A are each individually inserted into the upper switch hole 515a. The upper drain terminal 532A and the upper source terminal 533A are the drain terminal 532 and source terminal 533 of the upper arm switch section 530A. The upper drain terminal 532A is connected to the P busbar 601 so that it can be energized via the upper switch hole 515a. The upper source terminal 533A is connected to the output busbar 603 so that it can be energized via the upper switch hole 515a. The upper drain terminal 532A corresponds to the upper input terminal, and the upper source terminal 533A corresponds to the upper output terminal.

[0124] In the lower arm switch section 530B, the lower drain terminal 532B and the lower source terminal 533B are each individually inserted into the lower switch hole 515b. The lower drain terminal 532B and the lower source terminal 533B are the drain terminal 532 and source terminal 533 of the lower arm switch section 530B. The lower drain terminal 532B is connected to the output busbar 603 via the lower switch hole 515b so that power can be supplied. The lower source terminal 533B is connected to the N busbar 602 via the lower switch hole 515b so that power can be supplied. The lower drain terminal 532B corresponds to the lower input terminal, and the lower source terminal 533B corresponds to the lower output terminal.

[0125] In the upper capacitor section 580A, the upper P capacitor terminal 582A and the upper N capacitor terminal 583A are each individually inserted into the upper capacitor hole 515c. The upper P capacitor terminal 582A and the upper N capacitor terminal 583A are the P capacitor terminal 582 and N capacitor terminal 583 of the upper capacitor section 580A. The upper P capacitor terminal 582A is energetically connected to the P busbar 601 via the upper capacitor hole 515c. The upper N capacitor terminal 583A is energetically connected to the N busbar 602 via the upper capacitor hole 515c.

[0126] In the lower capacitor section 580B, the lower P capacitor terminal 582B and the lower N capacitor terminal 583B are each individually inserted into the lower capacitor hole 515d. The lower P capacitor terminal 582B and the lower N capacitor terminal 583B are the P capacitor terminal 582 and N capacitor terminal 583 of the lower capacitor section 580B. The lower P capacitor terminal 582B is energetically connected to the P busbar 601 via the lower capacitor hole 515d. The lower N capacitor terminal 583B is energetically connected to the N busbar 602 via the lower capacitor hole 515d.

[0127] In the high-voltage circuit board 510, the terminals 532A and 533A of the upper arm switch section 530A and the terminals 582A and 583A of the upper capacitor section 580A are arranged radially RD. The terminals 582A and 583A of the upper capacitor section 580A are located radially inward from the terminals 532A and 533A of the upper arm switch section 530A. Similarly, the terminals 532B and 533B of the lower arm switch section 530B and the terminals 582B and 583B of the lower capacitor section 580B are arranged radially RD. The terminals 582B and 583B of the lower capacitor section 580B are located radially inward from the terminals 532B and 533B of the lower arm switch section 530B.

[0128] The arm switch section 530 and the smoothing capacitor section 580 are connected to busbars 601-603 in the first busbar set 611 and the second busbar set 612, respectively. The connection configuration between the arm switch section 530 and the smoothing capacitor section 580 and busbars 601-603 is the same for the first busbar set 611 and the second busbar set 612. The second busbar set 612 is not shown in Figures 16-19. In Figure 7, the plan view of the high-voltage board 510, the plan view of the P busbar 601, the plan view of the output busbar 603, and the plan view of the N busbar 602 are arranged from top to bottom.

[0129] As shown in Figures 18 and 19, currents IpA, IpB, InA, InB, IoA, and IoB flow through the high-voltage substrate 510. The currents IpA, IpB, InA, InB, IoA, and IoB flow in the same way through the first busset 611 and the second busset 612. In this embodiment, the currents IpA, IpB, InA, InB, IoA, and IoB flowing through the first busset 611 will be described. The description of the currents IpA, IpB, InA, InB, IoA, and IoB flowing through the second busset 612 will be omitted.

[0130] In the output busbar 603, an upper output current IoA and a lower output current IoB flow. The output currents IoA and IoB as a whole flow circumferentially along the CD. The output currents IoA and IoB as a whole flow from the upper switch group 530GA to the lower switch group 530GB in one phase. In detail, the upper output current IoA flows circumferentially along the CD from the upper source terminal 533A towards the output connection 514. The lower output current IoB flows circumferentially along the CD from the output connection 514 towards the lower drain terminal 532B. The upper output current IoA and the lower output current IoB correspond to the output currents.

[0131] The high-voltage substrate 510 has an overlapping region AO. The overlapping region AO is the region that overlaps with the output currents IoA and IoB flowing through the output busbar 603. The overlapping region AO exists individually for each of the multiple phases. For example, the overlapping region AO exists individually for each of the multiple output busbars 603. The overlapping region AO is the region that overlaps with the upper switch group 530GA and the lower switch group 530GB included in one phase of the busbars 601 to 603. The overlapping region AO includes the entirety of the busbars 601 to 603 in the radial direction RD. In addition, the overlapping region AO includes the region where the arm switch section 530 and the smoothing capacitor section 580 are provided in the circumferential direction CD.

[0132] The overlapping region AO extends circumferentially in the direction CD so as to span the furthest upper component 530Af and the furthest lower component 530Bf. The furthest upper component 530Af is the upper arm switch component 530A of the upper switch group 530GA that is furthest from the lower switch group 530GB. The furthest upper component 530Af is located at the end of the upper switch group 530GA opposite to the lower switch group 530GB. The furthest lower component 530Bf is the lower arm switch component 530B of the lower switch group 530GB that is furthest from the upper switch group 530GA. The furthest lower component 530Bf is located at the end of the lower switch group 530GB opposite to the upper switch group 530GA.

[0133] The overlapping region AO is connected to the terminals 532A and 533A of the furthest upper component 530Af and the terminals 532B and 533B of the furthest lower component 530Bf. The overlapping region AO includes these terminals 532A, 533A, 532B, and 533B. The overlapping region AO includes at least the upper source terminal 533A of the furthest upper component 530Af and the lower drain terminal 532B of the furthest lower component 530Bf.

[0134] In the P busbar 601, an upper P current IpA and a lower P current IpB flow. The P currents IpA and IpB as a whole flow in the circumferential direction CD. The P currents IpA and IpB as a whole flow in one phase from the upper capacitor group 580GA and the lower capacitor group 580GB towards the upper switch group 530GA. The P currents IpA and IpB as a whole flow in the circumferential direction CD in the opposite direction to the output currents IoA and IoB. Specifically, the upper P current IpA flows in the circumferential direction CD from the upper P capacitor terminal 582A towards the upper drain terminal 532A. The lower P current IpB flows in the circumferential direction CD from the lower P capacitor terminal 582B towards the upper drain terminal 532A. The lower P current IpB flows in the circumferential direction CD in the opposite direction to the output currents IoA and IoB. The P currents IpA and IpB correspond to the high-potential current and the parallel current.

[0135] In the N busbar 602, an upper N current InA and a lower N current InB flow. The N currents InA and InB as a whole flow in the circumferential direction CD. The N currents InA and InB as a whole flow in one phase from the lower switch group 530GB to the upper capacitor group 580GA and the lower capacitor group 580GB. The N currents InA and InB as a whole flow in the circumferential direction CD in the opposite direction to the output currents IoA and IoB. Specifically, the upper N current InA flows in the circumferential direction CD from the lower source terminal 533B to the upper N capacitor terminal 583A. The lower N current InB flows in the circumferential direction CD from the lower source terminal 533B to the lower N capacitor terminal 583B. The lower N current InB flows in the circumferential direction CD in the opposite direction to the output currents IoA and IoB. The N currents InA and InB correspond to the low-potential current and the parallel current.

[0136] The P currents IpA and IpB and the N currents InA and InB flow in the same direction in the circumferential direction CD, but in opposite directions in the radial direction RD. This is because, in both the upper capacitor section 580A and the lower capacitor section 580B, the P capacitor terminals 582A and 582B and the N capacitor terminals 583A and 583B are aligned in the radial direction RD. For example, the lower P current IpB flows from the lower P capacitor terminal 582B towards the upper drain terminal 532A, flowing radially outward while simultaneously flowing circumferentially CD. Similarly, the lower N current InB flows radially inward from the lower source terminal 533B towards the upper N capacitor terminal 583A, flowing radially inward while simultaneously flowing circumferentially CD.

[0137] In the P busbar 601, the upper P current IpA flows from the upper P capacitor terminal 582A, which is radially outward from the upper N capacitor terminal 583A, to the upper drain terminal 532A. The lower P current IpB flows from the lower P capacitor terminal 582B, which is radially inward from the lower N capacitor terminal 583B, to the upper drain terminal 532A. Thus, the distance over which the upper P current IpA flows radially RD is different from the distance over which the lower P current IpB flows radially RD. In this embodiment, the distance over which the upper P current IpA flows radially outward is shorter than the distance over which the lower P current IpB flows radially outward.

[0138] In the N busbar 602, the lower N current InB flowing out from the lower source terminal 533B flows into the lower N capacitor terminal 583B, which is radially outward from the lower P capacitor terminal 582B. Similarly, the upper N current InA flowing out from the lower source terminal 533B flows into the upper N capacitor terminal 583A, which is radially inward from the upper P capacitor terminal 582A. Thus, the distance over which the lower N current InB flows radially RD is different from the distance over which the upper N current InA flows radially RD. In this embodiment, the distance over which the lower N current InB flows radially inward is shorter than the distance over which the upper N current InA flows radially inward.

[0139] In Figure 19, for illustrative purposes, currents IpA, IpB, InA, InB, IoA, and IoB are each illustrated with multiple arrows. In reality, currents IpA, IpB, InA, InB, IoA, and IoB flow together through busbars 601 to 603.

[0140] For example, the lower P current IpB flows through the P busbar 601 from multiple lower P capacitor terminals 582B to multiple upper drain terminals 532A. Therefore, the lower P current IpB increases as it approaches the output connection 514 in the circumferential direction CD. Then, the lower P current IpB decreases as it passes through the output connection 514 and moves away from it. Similarly to the lower P current IpB, the upper N current InA increases as it approaches the output connection 514 in the circumferential direction CD. Then, the upper N current InA decreases as it passes through the output connection 514 and moves away from it.

[0141] The upper output current IoA increases as it approaches the output connection 514 in the circumferential direction CD, until it reaches the output connection 514. The lower output current IoB decreases as it moves away from the output connection 514 in the circumferential direction CD. In the high-voltage substrate 510, the region in which the upper output current IoA increases as it approaches the output connection 514 and the region in which the lower P current IpB and upper N current InA increase as they approach the output connection 514 overlap in the axial direction AD. Therefore, the magnetic field generated by the upper output current IoA is likely to cancel out the magnetic field generated by the lower P current IpB and the magnetic field generated by the upper N current InA.

[0142] Furthermore, the region in which the lower output current IoB decreases as it moves away from the output connection 514 and the region in which the lower P current IpB and upper N current InA decrease as they move away from the output connection 514 overlap in the axial direction AD. As a result, the magnetic field generated by the lower output current IoB and the magnetic fields generated by the lower P current IpB and upper N current InA tend to cancel each other out. Consequently, the inductances L601 to L603 generated in the busbars 601 to 603 tend to be reduced.

[0143] As described above, in the high-voltage substrate 510, the current flow IpA, IpB, InA, InB, IoA, IoB is set so that the inductances L601 to L603 are reduced. By reducing the inductances L601 to L603 generated in the busbars 601 to 603, problems such as a decrease in the switching accuracy of the arm switch section 530 caused by the inductances L601 to L603 are suppressed.

[0144] The disadvantages caused by inductances L601 to L603 include a decrease in switching accuracy and current imbalance. Current imbalance occurs when, in a configuration in which multiple arm switch units 530 are connected in parallel, a difference in the switch current Id occurs among the multiple arm switch units 530. The switch current Id is the current flowing through the arm switch unit 530, as shown in Figure 18. The switch current Id is the current flowing through the drain of the arm switch 86 in the arm switch unit 530, and is sometimes referred to as the drain current.

[0145] Regarding current imbalance, a section of the inverter device 80 in which two upper arm switch sections 530A are connected in parallel will be explained as an example. As shown in Figure 20, the first switch section 530A1 and the second switch section 530A2 are connected in parallel as two upper arm switch sections 530A. Note that in Figure 20, only one of the multiple upper and lower arm circuits 83 of the inverter device 80 is shown. Also, of the multiple upper arms 84 and lower arms 85 that the single upper and lower arm circuit 83 has, only two upper arms 84 and two lower arms 85 are shown.

[0146] The inverter device 80 has a drive power supply 620. The drive power supply 620 applies a control voltage to the arm switch unit 530 to control the switching of the arm switch unit 530. The drive power supply 620 is provided, for example, in the drive circuit 160. The drive power supply 620 is energetically connected to the gate terminal 534 and the driver source terminal 535. The drive power supply 620 is connected to the gate terminal 534, for example, via a gate resistor R534. The parasitic inductance that occurs in the driver source path is referred to as inductance L534. The driver source path is the energetic path connecting the drive power supply 620 and the driver source terminal 535.

[0147] In the arm switch section 530, a control voltage from the drive power supply 620 is input to the gate terminal 534. The gate terminal 534 corresponds to the input control terminal. The gate voltage Vg of the gate terminal 534 is a value corresponding to the control voltage. The gate voltage Vg is the potential of the gate terminal 534. In the arm switch section 530, current is output from the driver source terminal 535 in conjunction with the input of the control voltage to the gate terminal 534. The driver source terminal 535 corresponds to the output control terminal.

[0148] The driver source voltage Vks at the driver source terminal 535 increases or decreases in accordance with the source voltage Vs at the source terminal 533. The driver source voltage Vks is the potential at the driver source terminal 535. The source voltage Vs is the potential at the source terminal 533. In the arm switch section 530, the parasitic inductance that occurs in the current path between the drain terminal 532 and the arm switch 86 is referred to as inductance L530d. The parasitic inductance that occurs in the current path between the arm switch 86 and the source terminal 533 is referred to as inductance L530S. The driver source voltage Vks is at a potential higher than the source voltage Vs by the amount of inductance L530S.

[0149] The source voltage Vs is at least as high as the potential of the output line 143 by the inductance voltage Vl. The inductance voltage Vl is the voltage across the inductance Ls. The inductance Ls is the parasitic inductance in the source path. The source path is the current-carrying path connecting the source terminal 533 and the output line 143. At least a portion of the source path is formed by the output busbar 603. The inductance Ls includes the inductance L603 that occurs in the output busbar 603. Therefore, the larger the inductance L603 that occurs in the output busbar 603, the larger the inductance Ls in the source path becomes, and the inductance voltage Vl increases.

[0150] For example, unlike this embodiment, let's consider Comparative Example 1, where the current flow IpA, IpB, InA, InB, IoA, IoB is not such that the inductances L601~L603 are reduced. In this Comparative Example 1, the large inductance L603 generated in the output busbar 603 increases the inductance Ls generated in the source path. As a result, the inductance voltage Vl increases, and the source voltage Vs increases. In the arm switch section 530, when the source voltage Vs increases, the driver source voltage Vks also increases.

[0151] In Comparative Example 1, the source voltage Vs at the first switch section 530A1 and the source voltage Vs at the second switch section 530A2 tend to differ. For example, if the distance between the second switch section 530A2 and the output connection section 514 is greater than the distance between the first switch section 530A1 and the output connection section 514, the source path of the first switch section 530A1 becomes longer than the source path of the second switch section 530A2. As a result, the inductance Ls2 for the second switch section 530A2 becomes greater than the inductance Ls1 for the first switch section 530A1. Consequently, the inductance voltage Vl2 for the second switch section 530A2 becomes greater than the inductance voltage Vl1 for the first switch section 530A1. Then, the source voltage Vs at the second switch section 530A2 becomes higher than the source voltage Vs at the first switch section 530A1, and the driver source voltage Vks at the second switch section 530A2 becomes higher than the driver source voltage Vks at the first switch section 530A1.

[0152] When a potential difference occurs in the driver source voltage Vks between the first switch section 530A1 and the second switch section 530A2, a circulating current Ik flows between the first switch section 530A1 and the second switch section 530A2. This potential difference is sometimes referred to as the source potential difference.

[0153] In the arm switch section 530, a switch current Id flows according to the gate-source voltage Vgs. The gate-source voltage Vgs is the potential difference between the gate voltage Vg and the driver source voltage Vks. For example, the larger the gate-source voltage Vgs, the larger the switch current Id tends to be.

[0154] As described above, in Comparative Example 1, when a circulating current Ik is flowing, the gate-source voltage Vgs2 at the second switch section 530A2 is smaller than the gate-source voltage Vgs1 at the first switch section 530A1. This is because, while the gate voltage Vg is the same at both the first switch section 530A1 and the second switch section 530A2, the driver source voltage Vks at the second switch section 530A2 is higher than the driver source voltage Vks at the first switch section 530A1.

[0155] As shown in Figure 21, the switch currents Id1 and Id2 tend to differ between the first switch section 530A1 and the second switch section 530A2 due to the difference in gate-source voltages Vgs1 and Vgs2. As mentioned above, if the inductance Ls2 is greater than the inductance Ls1, the gate-source voltage Vgs2 in the second switch section 530A2 tends to be smaller than the gate-source voltage Vgs1 in the first switch section 530A1. Therefore, the switch current Id2 in the second switch section 530A2 tends to be smaller than the switch current Id1 in the first switch section 530A1. In this way, a current imbalance occurs between the first switch section 530A1 and the second switch section 530A2.

[0156] In multiple arm switch sections 530, if a current imbalance occurs, it is conceivable that differences in the degree of deterioration, such as aging, will occur. In other words, variations in the degree of deterioration will occur among the multiple arm switch sections 530. For example, as in Comparative Example 1, if the switch current Id1 is greater than the switch current Id2, the first switch section 530A1 is more prone to deterioration than the second switch section 530A2 due to the constant flow of a larger current.

[0157] In contrast, in this embodiment, the current flow IpA, IpB, InA, InB, IoA, IoB is such that the inductances L601 to L603 are reduced.

[0158] Furthermore, in this embodiment, the arm switch section 530 has a driver source terminal 535. In addition, in this embodiment, in the first switch section 530A1 and the second switch section 530A2 shown in Figure 20, the inductances Ls1 and Ls2 are included in the inductance L603. Therefore, by reducing the inductance L603, the inductances Ls1 and Ls2 can be reduced. The smaller the inductances Ls1 and Ls2, the smaller the difference between inductances Ls1 and Ls2, and the smaller the circulating current Ik. And the smaller the circulating current Ik, the smaller the difference between switch currents Id1 and Id2, and the less likely current imbalance is to occur. Also, the smaller the circulating current Ik, the smaller the difference between switch currents Id1 and Id2. For example, if the difference between inductances Ls1 and Ls2 can be made zero, the circulating current Ik can be made as small as possible, and current imbalance will hardly occur. This makes it less likely for there to be variations in the degree of deterioration between the first switch section 530A1 and the second switch section 530A2.

[0159] For example, unlike this embodiment, let's consider Comparative Example 2, in which the arm switch section 530 does not have a driver source terminal 535. In Comparative Example 2, as shown in Figure 22, the drive power supply 620 is connected to the gate terminal 534 and the source terminal 533 in a way that allows current to flow. Therefore, in Comparative Example 2, the circulating current Ik does not flow through the inductance L530S. The circulating current Ik is the current corresponding to the inductance Ls among the inductance Ls and the inductance L530S.

[0160] <Composition group C> As shown in Figure 23, the multiple arm switch units 530 are arranged in a circumferential direction CD along the outer peripheral edge 512 of the high-voltage substrate 510. These arm switch units 530 are also arranged in a circumferential direction CD along the outer peripheral edge 552 of the drive substrate 550. The multiple arm switch units 530 are provided on the inner circumferential surface 90b of the inverter outer peripheral wall 91. The arm switch row 530R extends in a circumferential direction CD along the outer peripheral edges 512 and 552 and is annular in shape. In the high-voltage substrate 510 and the drive substrate 550, the outer peripheral edges 512 and 552 extend continuously in the circumferential direction CD.

[0161] As shown in Figures 24 and 25, the switch body 531 has a body base 537 and a body heat dissipation section 538. The body base 537 is made of a resin material or the like and has electrical insulating properties. The body base 537 is, for example, molded resin. The body base 537 forms the outer casing of the switch body 531. The body base 537 forms at least a portion of the first plate surface 531a, the second plate surface 531b, the base end portion 531c, and the tip portion 531d of the body.

[0162] The main body heat dissipation section 538 is made of a metal material or the like and has thermal conductivity. The main body heat dissipation section 538 has higher thermal conductivity than, for example, the main body base 537. The main body heat dissipation section 538 is, for example, a metal plate formed in the shape of a plate. The main body heat dissipation section 538 is embedded in the main body base 537. In the switch body 531, the terminals 532 to 535 and the main body heat dissipation section 538 are electrically insulated from the main body base 537.

[0163] In the switch body 531, the heat dissipation of the second surface 531b is enhanced by the main body heat dissipation section 538. The heat dissipation of the second surface 531b is higher than that of the first surface 531a. When heat is generated in the switch body 531, the heat dissipation from the second surface 531b is greater than the heat dissipation from the first surface 531a. The main body heat dissipation section 538 is exposed from the second surface 531b but not from the first surface 531a. At least a portion of the main body heat dissipation section 538 forms the second surface 531b. For example, the second surface 531b includes a portion formed by the main body base 537 and a portion formed by the main body heat dissipation section 538. The main body heat dissipation section 538 is in contact with the inner circumferential surface 90b on the second surface 531b. The first panel surface 531a corresponds to the inner panel surface, and the second panel surface 531b corresponds to the outer panel surface.

[0164] In the arm switch section 530, power from the battery 31 is supplied to the drain terminal 532 and the source terminal 533. The drain terminal 532 and the source terminal 533 are power terminals to which power is supplied, and correspond to power terminals. The drain terminal 532 and the source terminal 533 are connected to the high-voltage board 510 so as to be energized. The high-voltage board 510 corresponds to the power connection target and the power board, and the outer edge 512 corresponds to the power outer edge. The drain terminal 532 is connected to the P busbar 601 or the output busbar 603 so as to be energized. The source terminal 533 is connected to the output busbar 603 or the N busbar 602. In Figure 24, the P busbar 601, N busbar 602 and the output busbar 603 are shown together, and the earth busbar 604 is not shown.

[0165] As shown in Figure 24, in the high-voltage substrate 510, the drain terminal 532 and the source terminal 533 are connected to through-holes 515. The drain terminal 532 and the source terminal 533 are connected to the P busbar 601, N busbar 602, or output busbar 603 in a state where they can be energized while inserted into the through-holes 515. Multiple through-holes 515 are arranged in a circumferential direction CD along at least the outer edge 512 of the high-voltage substrate 510. The through-holes 515 are included in the connection portion between the drain terminal 532 and the high-voltage substrate 510, and in the connection portion between the source terminal 533 and the high-voltage substrate 510. The P busbar 601, N busbar 602, and output busbar 603 correspond to power busbars.

[0166] The gate terminal 534 and the driver source terminal 535 are terminals for controlling the power conversion by switching the arm switch 86, and correspond to control terminals. The gate terminal 534 and the driver source terminal 535 are electrically connected to the drive board 550. The drive board 550 corresponds to the control connection target and the target board, and the outer edge 552 corresponds to the control outer edge. The gate terminal 534 and the driver source terminal 535 are electrically connected, for example, to the wiring pattern of the drive board 550.

[0167] In the drive board 550, the gate terminal 534 and the driver source terminal 535 are connected to the through-hole 555. The gate terminal 534 and the driver source terminal 535 are connected to the wiring pattern of the drive board 550 in a way that allows current to flow when they are inserted into the through-hole 555. Multiple through-holes 555 are arranged in a circumferential direction CD along the outer edge 552 of the drive board 550. The through-holes 555 are included in the connection portion between the gate terminal 534 and the drive board 550, and in the connection portion between the driver source terminal 535 and the drive board 550.

[0168] The high-voltage substrate 510 and the drive substrate 550 are facing each other. In the high-voltage substrate 510 and the drive substrate 550, the second high-voltage surface 510b and the first control surface 550a are facing each other. The high-voltage substrate 510 has a pair of plate surfaces, the first high-voltage surface 510a and the second high-voltage surface 510b. In the high-voltage substrate 510, the first high-voltage surface 510a faces the high-voltage side, and the second high-voltage surface 510b faces the drive substrate 550 side. The drive substrate 550 has a pair of plate surfaces, the first control surface 550a and the second control surface 550b. In the drive substrate 550, the first control surface 550a faces the high-voltage substrate 510 side, and the second control surface 550b faces the low-voltage side.

[0169] The switch body 531 is positioned closer to the high-voltage board 510 than to the drive board 550. The distance between the switch body 531 and the high-voltage board 510 is smaller than the distance between the switch body 531 and the drive board 550. The shortest distance between the switch body 531 and the high-voltage board 510 is the separation distance, and the shortest distance between the switch body 531 and the drive board 550 is the separation distance.

[0170] At least a portion of the switch body 531 is provided between the first high-voltage surface 510a and the second control surface 550b in the axial direction AD. In the switch body 531, at least the base end portion 531c is provided between the first high-voltage surface 510a and the second control surface 550b in the axial direction AD. The region between the first high-voltage surface 510a and the second control surface 550b in the axial direction AD is a substrate region on which the high-voltage substrate 510 and the drive substrate 550 are provided. The projected region obtained by projecting the substrate region radially outward includes at least the base end portion 531c of the switch body 531.

[0171] The switch body 531 is located on the high-voltage side of the substrate midline Cmid. In the switch body 531, the base end 531c is located between the substrate midline Cmid and the first high-voltage surface 510a in the axial direction AD. The base end 531c is located closer to the first high-voltage surface 510a than the substrate midline Cmid in the axial direction AD. The switch body 531 extends toward the high-voltage side of the high-voltage substrate 510 in the axial direction AD.

[0172] The substrate midline Cmid is a virtual line that passes through the midpoint between the high-voltage substrate 510 and the drive substrate 550. The midpoint between the high-voltage substrate 510 and the drive substrate 550 is, for example, the midpoint between the opposing surfaces of the high-voltage substrate 510 and the drive substrate 550. The substrate midline Cmid extends parallel to each surface of the high-voltage substrate 510 and the drive substrate 550. In the axial direction AD, the position through which the substrate midline Cmid passes is the midpoint between the high-voltage substrate 510 and the drive substrate 550.

[0173] The drain terminal 532 has a drain exposed portion 532ex. The drain exposed portion 532ex is the portion of the drain terminal 532 that spans between the switch body 531 and the high-voltage circuit board 510 and is exposed. The drain exposed portion 532ex connects the switch body 531 and the high-voltage circuit board 510 and corresponds to the power connection portion. If the drain exposed portion 532ex has a curved shape, the length of the drain exposed portion 532ex will be greater than the distance between the switch body 531 and the high-voltage circuit board 510.

[0174] The source terminal 533 has a source exposed portion 533ex. The source exposed portion 533ex is the part of the source terminal 533 that spans between the switch body 531 and the high-voltage circuit board 510 and is exposed. The source exposed portion 533ex connects the switch body 531 and the high-voltage circuit board 510 and corresponds to the power connection portion. If the source exposed portion 533ex is bent, the length of the source exposed portion 533ex will be greater than the distance between the switch body 531 and the high-voltage circuit board 510.

[0175] The gate terminal 534 has a gate exposed portion 534ex. The gate exposed portion 534ex is the portion of the gate terminal 534 that spans between the switch body 531 and the drive board 550 and is exposed. The gate exposed portion 534ex connects the switch body 531 and the drive board 550 and corresponds to the control connection portion. If the gate exposed portion 534ex is bent, the length of the gate exposed portion 534ex will be greater than the distance between the switch body 531 and the drive board 550.

[0176] The driver source terminal 535 has a drain source exposed portion 535ex. The drain source exposed portion 535ex is the exposed part of the driver source terminal 535 that spans between the switch body 531 and the drive board 550. The drain source exposed portion 535ex connects the switch body 531 and the drive board 550 and corresponds to the control connection portion. If the drain source exposed portion 535ex is bent, the length of the drain source exposed portion 535ex will be greater than the distance between the switch body 531 and the drive board 550.

[0177] Terminals 532 to 535 have a base extension 536a, a tip extension 536b, and an extension connecting portion 536c. The base extension 536a is the portion of terminals 532 to 535 that extends from the base end. The base extension 536a extends axially AD from the base end 531c of the main body. The tip extension 536b is the portion of terminals 532 to 535 that extends from the tip. The tip extension 536b extends axially AD along the base extension 536a from the high-voltage substrate 510 or the drive substrate 550. The tip extension 536b is inserted through through holes 515 and 555 and fixed to the high-voltage substrate 510 or the drive substrate 550. The extended connection portion 536c is the part that connects the base extension portion 536a and the tip extension portion 536b at terminals 532 to 535.

[0178] The drain terminal 532 and source terminal 533 are bent into an overall U-shape. The drain terminal 532 and source terminal 533 are folded so that they extend away from the high-voltage substrate 510 in the axial direction AD, and also extend towards the high-voltage substrate 510. In the drain terminal 532 and source terminal 533, the base extension portion 536a and the tip extension portion 536b extend in the same direction from the extension connection portion 536c. The drain terminal 532 and source terminal 533 have a U-turn shape, extending from the switch body 531 and then making a U-turn back.

[0179] The gate terminal 534 and the driver source terminal 535 are bent into a Z-shape overall. The gate terminal 534 and the driver source terminal 535 extend axially AD from the switch body 531 toward the drive board 550, including the portion that extends radially RD. In the gate terminal 534 and the driver source terminal 535, the base extension portion 536a and the tip extension portion 536b extend in opposite directions from the extension connection portion 536c.

[0180] <Configuration group D> The arm switch section 530 generates heat when energized and is considered a heat-generating component. The smoothing capacitor section 580 and the filter component 524 also generate heat when energized, similar to the arm switch section 530, but the heat generated by energization is less than that of the arm switch section 530. In other words, the heat generated by energizing the smoothing capacitor section 580 and the filter component 524 is less than the heat generated by energizing the arm switch section 530. The smoothing capacitor section 580 and the filter component 524 are considered low-heat-generating components.

[0181] In this embodiment, for electrically conductive components such as the arm switch section 530 that generate heat when energized, a large amount of heat generated and a high control temperature are referred to as having high heat generation. For example, in electrically conductive components, a larger amount of heat generated tends to result in a higher rate of temperature rise. Also, in electrically conductive components, a higher control temperature tends to result in higher high-temperature resistance.

[0182] The arm switch section 530 generates more heat and has a higher control temperature than the smoothing capacitor section 580 and the filter component 524, resulting in greater heat generation due to energization. For example, the heat generated by the arm switch section 530 is greater than that of the smoothing capacitor section 580 and the filter component 524. Furthermore, the control temperature of the arm switch section 530 is higher than that of the smoothing capacitor section 580 and the filter component 524. In addition, the arm switch section 530 generates the most heat due to energization among all the components constituting the inverter device 80.

[0183] The filter component 524 generates less heat when energized than the smoothing capacitor section 580. In other words, the heat generated when energized in the filter component 524 is less than the heat generated when energized in the smoothing capacitor section 580. The smoothing capacitor section 580 corresponds to the first low-heat component, and the filter component 524 corresponds to the second low-heat component.

[0184] As shown in Figure 26, the inverter device 80 has a capacitor row 580R, a filter row 524R, and an arm switch row 530R. All of these rows 580R, 524R, and 530R extend in an annular shape in the circumferential direction CD. The arm switch row 530R is located radially outward from the capacitor row 580R. The filter row 524R is located radially inward from the capacitor row 580R. The capacitor row 580R is provided between the arm switch row 530R and the filter row 524R in the radial direction RD. Note that in Figure 26, rows 580R, 524R, and 530R are represented by dashed lines.

[0185] The arm switch row 530R has multiple arm switch units 530. In the arm switch row 530R, multiple arm switch units 530 are arranged in the circumferential direction CD. For example, one row of arm switch row 530R extends in the circumferential direction CD. In one row of arm switch row 530R, one arm switch unit 530 is arranged in the circumferential direction CD along the entire circumferential direction CD. The arm switch row 530R extends along the inner circumferential surface 90b relative to the outer circumferential wall 91 of the inverter. The arm switch row 530R includes multiple switch groups 530G. The arm switch row 530R corresponds to a heat-generating component row.

[0186] The arm switch array 530R is ring-shaped overall. In the arm switch array 530R, there is a mixture of areas where the arm switch units 530 are spaced equally and areas where they are not spaced equally. In the arm switch array 530R, the distance between two adjacent arm switch units 530 in the circumferential direction CD is not uniform in the circumferential direction CD. For example, the distance between two adjacent switch groups 530G in the circumferential direction CD is greater than the distance between two adjacent arm switch units 530 in one switch group 530G in the circumferential direction CD. In addition, in the arm switch array 530R, components other than arm switch units 530, such as the motor current sensor 146, may be positioned between two adjacent arm switch units 530 in the circumferential direction CD.

[0187] The capacitor array 580R has multiple smoothing capacitor sections 580. In the capacitor array 580R, multiple smoothing capacitor sections 580 are arranged in the circumferential direction CD. For example, one capacitor array 580R extends in the circumferential direction CD. In one capacitor array 580R, one smoothing capacitor section 580 is arranged in the circumferential direction CD along the entire circumferential direction CD. The capacitor array 580R extends along the outer edge 512 relative to the high-voltage substrate 510. The capacitor array 580R includes multiple capacitor groups 580G. The capacitor array 580R corresponds to the small thermal component array and the first component array.

[0188] The capacitor array 580R is ring-shaped overall. In the capacitor array 580R, there is a mixture of areas where the smoothing capacitor sections 580 are arranged at equal intervals and areas where they are not. In the capacitor array 580R, the distance between two adjacent smoothing capacitor sections 580 along the circumferential CD is not uniform along the circumferential CD. For example, the distance between two adjacent capacitor groups 580G along the circumferential CD is greater than the distance between two adjacent smoothing capacitor sections 580 in one capacitor group 580G along the circumferential CD. In addition, in the capacitor array 580R, components other than the smoothing capacitor section 580, such as the motor current sensor 146, may be positioned between two adjacent smoothing capacitor sections 580 along the circumferential CD.

[0189] The filter array 524R has multiple filter components 524. In the filter array 524R, multiple smoothing capacitor sections 580 are arranged in the circumferential direction CD. For example, one filter array 524R extends in the circumferential direction CD. In one filter array 524R, at least a portion of the circumferential direction CD has one filter component 524 arranged in the circumferential direction CD. The filter array 524R extends along the inner circumferential end 511 with respect to the high-voltage substrate 510. The filter array 524R corresponds to the small heat component array and the second component array.

[0190] The filter array 524R is ring-shaped overall. In the filter array 524R, the filter components 524 are not spaced equally in the circumferential direction CD. In the filter array 524R, common mode coil sections 525, normal mode coil sections 526, Y capacitor sections 527, and X capacitor sections 528 are arranged in a mixed manner. In addition, in the filter array 524R, components other than filter components 524, such as the current sensor 147, may be positioned between two adjacent filter components 524 in the circumferential direction CD.

[0191] Multiple smoothing capacitor sections 580 include group-aligned components 580c. Similarly, multiple filter components 524 include group-aligned components 524a. The group-aligned components 580c and 524a are positioned radially RD relative to the switch group 530G. At least a portion of the group-aligned components 580c and 524a are positioned radially RD relative to the switch group 530G. For example, among the multiple filter components 524, a filter component 524 located between two adjacent switch groups 530G in the circumferential direction CD is not a group-aligned component 580c. Note that the switch group 530G corresponds to the heat generation group.

[0192] The group of components 580c and 524a are positioned at projection locations that are projected onto the arm switch section 530 in the radial direction RD. The projection location is a position where at least a portion of the projection plane obtained by projecting the group of components 580c and 524a radially outward overlaps with the arm switch section 530. The group of components 580c and 524a at the projection location and the arm switch section 530 on which the projection planes of these group of components 580c and 524a overlap are aligned in the radial direction RD.

[0193] The inverter device 80 has a switch area Asw1 and an intermediate area Asw2. Switch area Asw1 is an area where a switch group 530G is provided and extends in the circumferential direction CD along the inner circumferential surface 90b. Multiple switch areas Asw1 are arranged along the circumferential direction CD. One switch area Asw1 is an area where one switch group 530G is provided. In switch area Asw1, multiple arm switches 86 belonging to the switch group 530G are arranged in a dense cluster. Switch area Asw1 corresponds to a dense cluster area.

[0194] The intermediate region Asw2 is a region located between two adjacent switch regions Asw1 along the circumferential CD. The intermediate region Asw2 spans across the two adjacent switch regions Asw1 along the circumferential CD and extends along the inner circumferential surface 90b in the circumferential CD direction. The intermediate region Asw2 is a region where the switch group 530G is not provided and where the arm switch portion 530 is not provided. Multiple intermediate regions Asw2 are arranged along the inner circumferential surface 90b in the circumferential CD direction. The switch regions Asw1 and intermediate regions Asw2 are arranged alternately along the circumferential CD direction.

[0195] The inverter device 80 includes components and parts located in a radial direction RD relative to the switch region Asw1. For example, the inverter fin group 93, and the group components 580c and 524a are located in a radial direction RD relative to the switch region Asw1. The inverter device 80 also includes components and parts located in a radial direction RD relative to the intermediate region Asw2. For example, the flanges 94 and 95, the inverter connector 96, and the connector component 524b are located in a radial direction RD relative to the intermediate region Asw2.

[0196] The connector arrangement component 524b is included in the multiple filter components 524. The connector arrangement component 524b is positioned radially RD relative to the inverter connector 96. At least a portion of the connector arrangement component 524b is positioned radially RD relative to the inverter connector 96. For example, among the multiple filter components 524, group arrangement component 524a is not the connector arrangement component 524b.

[0197] The inverter connector 96 is a connector for connecting the arm switch 86 to the battery 31 so that power can be supplied to it. The battery 31 corresponds to an external device, and the inverter connector 96 corresponds to an external connector.

[0198] As shown in Figure 27, the inverter device 80 has a switch pressing portion 539. The switch pressing portion 539 presses the arm switch portion 530 toward the inverter outer peripheral wall 91. The switch pressing portion 539 is an elastically deformable member and is formed by a biasing member such as a leaf spring. The switch pressing portion 539 is fixed to the inverter outer peripheral wall 91 in an elastically deformed state and, by its restoring force, presses the switch body 531 radially outward toward the inner peripheral surface 90b. In the switch pressing portion 539, for example, one end is fixed to the inverter outer peripheral wall 91 by a fastener such as a bolt, and the other end is hooked onto the first plate surface 531a.

[0199] The switch body 531 is in contact with the inner circumferential surface 90b and is fixed to the inverter outer circumferential wall 91 with an adhesive or the like. The switch body 531 may be in direct contact with the inner circumferential surface 90b or indirect contact with the inner circumferential surface 90b. Whether the contact between the switch body 531 and the inner circumferential surface 90b is direct or indirect, it is sufficient that heat is transferred between the switch body 531 and the inner circumferential surface 90b. For example, in a configuration where the switch body 531 is indirectly in contact with the inner circumferential surface 90b, the switch body 531 is superimposed on the inner circumferential surface 90b via a heat conductive member. The heat conductive member is a material that has thermal conductivity, such as gel, grease, or adhesive. In this configuration, heat transfer between the switch body 531 and the inverter outer circumferential wall 91 is performed via the heat conductive member.

[0200] The switch body 531 is in contact with the inner circumferential surface 90b and is further pressed against the inner circumferential surface 90b by the switch pressing portion 539. In the switch body 531, the pressing force of the switch pressing portion 539 makes it easier for the second plate surface 531b to adhere closely to the inner circumferential surface 90b. As a result, heat from the switch body 531 is easily transferred to the outer wall of the switch. The second plate surface 531b may be directly or indirectly superimposed on the inner circumferential surface 90b. Note that the switch body 531 corresponds to the component body, and terminals 532 to 535 correspond to component terminals.

[0201] The high-voltage substrate 510 and the drive substrate 550 are thermally conductive and can transfer heat to the arm switch section 530 and the component support section 500. The terminals 532-535 are connected to the substrates 510 and 550, enabling heat transfer between the substrates 510 and 550 and the arm switch section 530. Heat transfer between the substrates 510 and 550 and the component support section 500 occurs via contact points where the substrates 510 and 550 and the component support section 500 are in contact. The contact points between the substrates 510 and 550 and the component support section 500 include the high-voltage fixing section 507 and the drive fixing section 508. The high-voltage substrate 510 and the drive substrate 550 correspond to the connecting substrates, and the component support section 500 corresponds to the substrate support section.

[0202] The high-voltage fixing portion 507 is included in the component support portion 500. The high-voltage fixing portion 507 is provided on at least one of the beam portion 501 and the beam connecting portion 502. The high-voltage substrate 510 is fixed to the component support portion 500 in contact with the high-voltage fixing portion 507. The high-voltage fixing portion 507 is, for example, a protrusion that projects from the beam portion 501 toward the high-voltage side. The high-voltage fixing portion 507 is provided with screw holes 505. The drain terminal 532 and the source terminal 533 are capable of transferring heat to the inverter outer peripheral wall 91 via the high-voltage substrate 510 and the component support portion 500.

[0203] The drive fixing portion 508 is included in the component support portion 500. The drive fixing portion 508 is provided on at least one of the beam portion 501 and the beam connecting portion 502. The drive board 550 is fixed to the component support portion 500 in contact with the drive fixing portion 508. The drive fixing portion 508 is, for example, a protrusion that projects from the beam portion 501 toward the low-pressure side. The drive fixing portion 508 is provided with screw holes 506. The gate terminal 534 and the driver source terminal 535 are capable of transferring heat to the inverter outer peripheral wall 91 via the drive board 550 and the component support portion 500.

[0204] As shown in Figures 27 and 28, the heat dissipation paths that release heat from the arm switch section 530 to the outside of the inverter device 80 include heat dissipation paths PH1 to PH3. The first heat dissipation path PH1 is a path that releases heat from the switch body 531 to the outside from the inverter outer peripheral wall 91. In the first heat dissipation path PH1, the heat from the switch body 531 is directly transferred to the inner peripheral surface 90b, and that heat is released to the outside from the outer peripheral surface 90a via the inverter fins 92. The outer peripheral surface 90a corresponds to a heat dissipation surface that releases the heat transferred to the inner peripheral surface 90b to the outside. The heat transferred through the first heat dissipation path PH1 is easily released from the outer peripheral surface 90a, which is aligned radially RD in the switch region Asw1. The outer peripheral surface 90a is sometimes referred to as the heat dissipation end. In particular, the part of the outer peripheral surface 90a that is aligned radially RD in the switch region Asw1 is sometimes referred to as the first heat dissipation end.

[0205] In the arm switch array 530R, heat is dissipated from each of the multiple arm switch units 530 via the first heat dissipation path PH1. In this case, in the inverter device 80, the heat from the multiple arm switch units 530 is released radially outward from the outer surface 90a, as shown in the multiple first heat dissipation paths PH1 in Figure 28. In this way, the first heat dissipation paths PH1 corresponding to the multiple arm switch units 530 are less likely to overlap with each other. That is, the heat from the multiple arm switch units 530 is easily released to the outside via different paths.

[0206] The second heat dissipation path PH2 is a path that releases heat from the drain terminal 532 and source terminal 533 to the outside from the inverter outer peripheral wall 91 via the high-voltage substrate 510 and component support portion 500. In the second heat dissipation path PH2, heat from the drain terminal 532 and source terminal 533 is transferred to the high-voltage substrate 510, and that heat is transferred to the inverter outer peripheral wall 91 via the component support portion 500 and released to the outside from the outer peripheral surface 90a. The heat transmitted through the second heat dissipation path PH2 is easily released from the parts of the outer peripheral surface 90a that are aligned radially RD in the intermediate region Asw2. The parts of the outer peripheral surface 90a that are aligned radially RD in the intermediate region Asw2 are sometimes referred to as the second heat dissipation end.

[0207] The third heat dissipation path PH3 is a path that releases heat from the gate terminal 534 and driver source terminal 535 to the outside from the inverter outer peripheral wall 91 via the drive board 550 and component support section 500. In the third heat dissipation path PH3, heat from the gate terminal 534 and driver source terminal 535 is transferred to the drive board 550, and that heat is transferred to the inverter outer peripheral wall 91 via the component support section 500 and released to the outside from the outer peripheral surface 90a. The heat that has traveled through the third heat dissipation path PH3 is most easily released from the parts of the outer peripheral surface 90a that are aligned radially RD in the intermediate region Asw2.

[0208] <Composition group A> According to the embodiment described above, the components mounted on the inverter device 80 are fixed to the beam portion 501 via plate members, namely the high-voltage substrate 510 and the drive substrate 550. In this configuration, the multiple beam portions 501 and the high-voltage substrate 510 and drive substrate 550 mutually restrict the stresses acting on them in the XYZ directions. In other words, the structure in which the mounted components are sandwiched and fixed between multiple lightweight beam portions 501 and plate members is a lightweight and highly strong shape that is resistant to vibration. In this way, even if vibrations are transmitted from the inverter outer wall 91 to the beam portions 501, the mounted components are suppressed from vibrating excessively, thereby improving the vibration resistance of the inverter device 80.

[0209] In the EPU 50, the inverter outer wall 91 is fixed to the motor outer wall 71 of the motor unit 60, which has relatively little vibration, by a high-pressure side flange 94, etc. In other words, the inverter unit 80 is coupled to the motor outer wall 71, which holds the stator 200 and has little vibration, rather than to the rear end plate 62, which has a large vibration, in order to support the rotor 300 of the motor unit 60. This reduces the impact of vibration on the inverter unit 80. Furthermore, since the components mounted on the inverter unit 80 are fixed to the beam section 501 via plate members called the high-pressure substrate 510 and the drive substrate 550, the vibration resistance of the inverter unit 80 can be increased as described above. In addition, if the cooling of the rear end plate 62 of the motor unit 60 is insufficient, the rear end plate 62 will become hot, but since an air layer is interposed between it and the components mounted on the inverter unit 80, it is possible to prevent heat damage to the mounted components.

[0210] In this embodiment, a high-voltage substrate 510 is provided on one side of the beam portion 501 in the axial direction AD, and a drive substrate 550 is provided on the opposite side of the beam portion 501 from the high-voltage substrate 510 via the beam portion 501. In this configuration, the two plate members, the high-voltage substrate 510 and the drive substrate 550, restrict the individual vibration of the multiple beam portions 501 from both the one side and the other side of the axial direction AD. Therefore, a configuration in which the beam portions 501 are less prone to vibration can be realized by the high-voltage substrate 510 and the drive substrate 550.

[0211] Furthermore, in the inverter device 80, a sandwich structure is formed by multiple beam sections 501, a high-voltage substrate 510, and a drive substrate 550. Because the support structure for the mounted components is a sandwich structure, the strength of the support structure can be increased. Therefore, the effect of suppressing vibrations of the mounted components can be enhanced by the sandwich structure. Moreover, the sandwich structure allows for a reduction in the weight of the support structure.

[0212] In this embodiment, the plate members that restrict the vibration of the beam section 501 are the high-voltage substrate 510 and the drive substrate 550. In this configuration, there is no need to use a dedicated plate member to restrict the vibration of the beam section 501. For example, in a configuration different from this embodiment, where a dedicated plate member is stretched across and fixed to multiple beam sections 501, there is a concern that the electrical wiring and wiring work for supplying power to the mounted components will become complicated. In contrast, in this embodiment, the high-voltage substrate 510 and the drive substrate 550 make it possible to simplify the electrical wiring and restrict the vibration of the beam section 501. Furthermore, by using multilayer wiring in the high-voltage substrate 510 and the drive substrate 550, the electrical characteristics of the inverter device 80 can be improved.

[0213] In this embodiment, the beam section 501 located between the high-voltage substrate 510 and the drive substrate 550 is grounded to the earth. In this configuration, the beam section 501 suppresses the application of electromagnetic fields generated when high-voltage components such as the high-voltage substrate 510 are energized to low-voltage components such as the drive substrate 550. Thus, because the influence of electromagnetic fields from high-voltage components is reduced by the beam section 501, a noise-resistant inverter device 80 can be realized. Furthermore, the grounding path, which is grounded to the earth, is formed including the beam section 501. Therefore, there is no need to use a dedicated grounding wire to ground high-voltage components and low-voltage components to the earth. Consequently, by placing the earth on the surface or inner layer of the high-voltage substrate 510 and the drive substrate 550, and energizing this earth to multiple beam sections 501, it becomes easy to ground noise from high-voltage components and low-voltage components to the earth with low impedance.

[0214] According to this embodiment, multiple arm switch units 530 are fixed to the inner circumferential surface 90b of the inverter outer circumferential wall 91 and arranged in a circumferential direction CD along the inner circumferential surface 90b. In this configuration, when the arm switch units 530 generate heat due to the operation of the inverter device 80, this heat is easily released to the outside through the inverter outer circumferential wall 91. Therefore, it is possible to suppress the temperature of the arm switch units 530 from becoming excessively high and the heat of the arm switch units 530 from accumulating inside the inverter housing 90. Accordingly, it is possible to prioritize vibration reduction for mounted components among the energized components and heat dissipation for the arm switch units 530 among the energized components. This makes it possible to achieve both improved vibration resistance of the inverter device 80 and improved heat dissipation of the inverter device 80.

[0215] Furthermore, multiple arm switch units 530 are arranged along the outer peripheral edge 512 relative to the high-voltage substrate 510 and the control substrate 560. In this configuration, the distance between the arm switch units 530 and the high-voltage substrate 510 and the control substrate 560 in the radial direction RD can be made uniform across the multiple arm switch units 530. This prevents excessive variation in the length of terminals 532 to 535 extending from the arm switch units 530 toward the substrates 510 and 550 across the multiple arm switch units 530. In addition, by connecting multiple arm switch units 530 in parallel, it is possible to reduce inductance and thermal resistance by distributing heat sources. Moreover, connecting the arm switch units 530 in parallel reduces the effect of the heat spreader on the inverter outer peripheral wall 91 located between the arm switch units 530 and the inverter fins 92, thereby improving the cooling effect and allowing the inverter outer peripheral wall 91 to be made thinner and lighter.

[0216] According to this embodiment, the beam portion 501 extends radially inward from the inverter outer wall 91 between two adjacent switch groups 530G in the circumferential direction CD. In this configuration, the beam portion 501 can be positioned in a location that does not interfere with the arm switch portion 530.

[0217] According to this embodiment, the switch body 531 of the arm switch section 530 is positioned at a distance from the beam section 501, the high-voltage substrate 510, and the drive substrate 550. In this configuration, the heat generated in the switch body 531 is easily transferred directly to the inverter outer wall 91 without passing through the beam section 501, the high-voltage substrate 510, and the drive substrate 550. Therefore, the heat from the switch body 531 can suppress the temperature rise of the beam section 501, the high-voltage substrate 510, and the drive substrate 550.

[0218] According to this embodiment, the arm switch section 530 is provided in a position where the inverter fins 92 are aligned in the radial direction RD. In this configuration, the inverter fins 92 are located at the position closest to the arm switch section 530 on the outer peripheral surface 90a formed by the inverter outer peripheral wall 91. Therefore, the inverter fins 92 can be positioned at the location where the heat dissipation effect of the arm switch section 530 is maximized.

[0219] In this embodiment, multiple beam sections 501 are connected by beam connecting sections 502. In this configuration, the beam connecting sections 502 restrict the individual vibration of the multiple beam sections 501. As a result, the strength of the structure consisting of the high-voltage substrate 510, the drive substrate 550, and the multiple beam sections 501 is increased, and vibrations transmitted to mounted components can be reduced.

[0220] In this embodiment, the inside of the beam connection portion 502 is opened in a donut shape for the high-voltage substrate 510 and the drive substrate 550. The weight is lighter near the center. As a result, the resonant frequency of the beam portion 501 and the beam connection portion 502 is increased, making it possible to realize a configuration in which the beam portion 501 and the beam connection portion 502 are less likely to resonate with vibrations from the motor device 60 and the like. Therefore, the strength of the inverter housing 90 against vibrations can be increased.

[0221] According to this embodiment, the beam section 501 and the inverter outer wall 91 are capable of heat transfer. Therefore, even if heat is generated in the current-carrying components such as the smoothing capacitor section 580 and the high-voltage substrate 510, this heat is easily released to the outside from the beam section 501 through the inverter outer wall 91. The connection point between the beam section 501 and the inverter outer wall 91 avoids the mounting of the arm switch section 530, resulting in a lower temperature than the arm switch section 530 and improved heat dissipation.

[0222] According to this embodiment, the beam portion 501 and the inverter outer wall 91 are electrically connected. Therefore, the filter component 524 and the high-voltage substrate 510 can be grounded to the earth via the conductive path including the beam portion 501 and the inverter outer wall 91. Consequently, the EMC performance of the inverter device 80 can be improved by the beam portion 501. In addition, the configuration for grounding the filter component 524 and the high-voltage substrate 510 to the earth can be simplified, and it becomes easier to arrange electrical safety components such as the varistor 155.

[0223] According to this embodiment, the heat insulating section 545 is provided between the high-voltage substrate 510 and the rear end plate 62 and extends along the rear end plate 62. In this configuration, the heat insulating section 545 is provided between the mounted components of the inverter device 80, which have a low heat resistance temperature, and the rear end plate 62. Therefore, even if the rear end plate 62 becomes hot due to the heat from the stator 200 and other components in the motor device 60, it is possible to prevent heat damage in the inverter device 80.

[0224] <Composition group B> According to this embodiment, the output busbar 603 is connected to the upper arm switch section 530A and the lower arm switch section 530B at positions spaced apart in the circumferential direction CD. In this configuration, it becomes possible to change the spacing between the upper arm switch section 530A and the lower arm switch section 530B. Therefore, compared to a configuration in which the upper arm switch section 530A and the lower arm switch section 530B are integrated, for example, the degree of freedom regarding the arrangement of the arm switch sections 530A and 530B can be increased.

[0225] Furthermore, in the overlapping region AO, the P currents IpA and IpB flowing through the P busbar 601, and the N currents InA and InB flowing through the N busbar 602, flow in opposite directions in the circumferential direction CD to the output currents IoA and IoB flowing through the output busbar 603. In this configuration, the magnetic fields generated by the P currents IpA and IpB and the N currents InA and InB tend to cancel each other out, as do the magnetic fields generated by the output currents IoA and IoB. As a result, the parasitic inductances L601 to L603 in the busbars 601 to 603 tend to be reduced. Consequently, a decrease in the operating accuracy of the upper arm switch section 530A and the lower arm switch section 530B can be suppressed.

[0226] As a result, it is possible to achieve both increased flexibility in the arrangement of the arm switch sections 530A and 530B and improved operating accuracy of the inverter device 80.

[0227] In this embodiment, multiple upper arm switch sections 530A included in one phase are connected in parallel to each other on the P busbar 601 and the output busbar 603. Furthermore, multiple lower arm switch sections 530B included in one phase are connected in parallel to each other on the N busbar 602 and the output busbar 603. In this configuration, it is easy to arrange the multiple upper arm switch sections 530A and the multiple lower arm switch sections 530B along the busbars 601 to 603 in a circumferential direction CD.

[0228] The upper arm switch section 530A and the lower arm switch section 530B have a driver source terminal 535 that is different from the source terminal 533. When multiple arm switch sections 530A and 530B having driver source terminals 535 are connected in parallel, there is a concern that current imbalance will occur due to the parasitic inductances L601 to L603 in the busbars 601 to 603. In contrast, according to this embodiment, the current flow IpA, IpB, InA, InB, IoA, and IoB in the busbars 601 to 603 is set so as to reduce the inductances L601 to L603. Therefore, current imbalance can be suppressed by reducing the inductances L601 to L603. Consequently, it is possible to suppress variations in the degree of degradation among multiple arm switch sections 530A and 530B that are connected in parallel with each other.

[0229] In this embodiment, multiple upper arm switch sections 530A and multiple lower arm switch sections 530B included in one phase are arranged in the circumferential direction CD along busbars 601 to 603. In this configuration, busbars 601 to 603 tend to extend in a long length in the circumferential direction CD to match the range in which the multiple arm switch sections 530A and 530B are arranged. When busbars 601 to 603 become long in this way, there is a concern that the parasitic inductances L601 to L603 associated with busbars 601 to 603 will increase.

[0230] In contrast, in this embodiment, the current flows IpA, IpB, InA, InB, IoA, and IoB are set to reduce the inductances L601 to L603. Therefore, even if the busbars 601 to 603 extend in a long manner in the circumferential direction CD, the parasitic inductances L601 to L603 associated with the busbars 601 to 603 can be reduced.

[0231] In this embodiment, multiple arm switch sections 530A and 530B included in one phase are arranged in the circumferential direction CD along the inner circumferential surface 90b. In this configuration, the heat from each of the multiple arm switch sections 530A and 530B is easily transferred to the inverter outer circumferential wall 91. Therefore, it is possible to suppress the temperature of the arm switch sections 530A and 530B from becoming excessively high, and the transfer of heat from one arm switch section 530A or 530B to the other arm switch sections 530A or 530B. Thus, the arrangement of the arm switch sections 530A and 530B can enhance the heat dissipation effect of the inverter device 80. As a result, both the reduction of parasitic inductance and the improvement of heat dissipation effect can be achieved in the inverter device 80.

[0232] Furthermore, since busbars 601-603 extend circumferentially in the direction CD along the inner surface 90b, the multiple arm switch sections 530A and 530B are arranged circumferentially in the direction CD along busbars 601-603. In this configuration, the current supply path connecting the upper arm switch section 530A to the P busbar 601 and the output busbar 603 can be made as short as possible in the radial direction RD. By shortening the current supply path leading to the upper arm switch section 530A in this way, the parasitic inductance generated in this current supply path can be reduced as much as possible. Similarly, the current supply path connecting the lower arm switch section 530B to the N busbar 602 and the output busbar 603 can be made as short as possible in the radial direction RD. By shortening the current supply path leading to the lower arm switch section 530B in this way, the parasitic inductance generated in this current supply path can be reduced as much as possible.

[0233] According to this embodiment, the arm switch sections 530A and 530B are provided on the inner circumferential surface 90b at positions radially outward from the busbars 601 to 603. In this configuration, heat from the arm switch sections 530A and 530B is directly transferred to the inner circumferential surface 90b. Therefore, the heat dissipation effect of the arm switch sections 530A and 530B can be enhanced by the inverter outer circumferential wall 91. Thus, the inverter device 80 can achieve both improved electrical characteristics, such as reduced parasitic inductance, and improved heat dissipation.

[0234] In this embodiment, in one of the upper capacitor section 580A and the lower capacitor section 580B, the P capacitor terminal 582 is radially outward from the N capacitor terminal 583, and in the other, the N capacitor terminal 583 is radially outward from the P capacitor terminal 582. In this configuration, in the P busbar 601, the distance over which one of the upper P current IpA and the lower P current IpB flows in the radial RD is shorter than the distance over which the other flows in the radial RD. Similarly, in the N busbar 602, the distance over which one of the upper N current InA and the lower N current InB flows in the radial RD is shorter than the distance over which the other flows in the radial RD. Therefore, it is possible to suppress the difference between the total distance over which the P currents IpA and IpB flow in the radial RD in the P busbar 601 and the total distance over which the N currents InA and InB flow in the radial RD in the N busbar 602 from becoming excessively large.

[0235] When the total distances across the P busbar 601 and the N busbar 602 are equalized in this way, the parasitic inductance L601 in the P busbar 601 and the parasitic inductance L602 in the N busbar 602 become easier to equalize. Therefore, it is possible to suppress the outflow of P currents IpA and IpB from the P busbar 601 and the outflow of N currents InA and InB from the N busbar 602. For example, it is possible to suppress the outflow of P currents IpA and IpB and N currents InA and InB flowing through the P busbar 601 and N busbar 602 as normal mode currents into the earth busbar 604 and become common mode currents. In other words, it is possible to suppress the occurrence of current mode conversion in busbars 601 to 604.

[0236] For example, unlike this embodiment, consider a configuration where the positional relationship between the P capacitor terminal 582 and the N capacitor terminal 583 is the same in the upper capacitor section 580A and the lower capacitor section 580B. In this configuration, the distance over which the upper P current IpA flows in the circumferential direction CD and the distance over which the lower P current IpB flows in the circumferential direction CD will be longer or shorter than the distance over which the upper N current InA flows in the circumferential direction CD and the distance over which the lower N current InB flows in the circumferential direction CD. As a result, the difference between the total distances at the P busbar 601 and the total distances at the N busbar 602 tends to be large. Consequently, the difference between the parasitic inductance L601 at the P busbar 601 and the parasitic inductance L602 at the N busbar 602 becomes large, raising concerns that current mode conversion may occur.

[0237] According to this embodiment, the overlapping region AO extends circumferentially to the CD so as to span between the furthest upper component 530Af included in the upper switch group 530GA and the furthest lower component 530Bf included in the lower switch group 530GB. In this configuration, it is possible to extend the overlapping region AO as far as possible circumferentially to the CD. Therefore, the range in which the P currents IpA, IpB and N currents InA, InB and the output currents IoA, IoB flow in overlapping manner tends to spread circumferentially to the CD. That is, the range in which the magnetic flux generated by the P currents IpA, IpB and the magnetic flux generated by the N currents InA, InB cancel each other out tends to spread circumferentially to the CD. Consequently, the range in which parasitic inductance is reduced by the cancellation of magnetic flux can be extended circumferentially to the CD, and as a result, the parasitic inductance of the busbars 601 to 603 as a whole can be reduced.

[0238] In this embodiment, multiple upper capacitor sections 580A and multiple lower capacitor sections 580B are arranged in the circumferential direction CD. In this configuration, the heat generated from the multiple upper capacitor sections 580A is easily dispersed. Therefore, the arrangement of the capacitor sections 580A and 580B can enhance the heat dissipation effect of the inverter device 80.

[0239] Furthermore, the overlapping region AO extends circumferentially along CD so as to span between the upper capacitor group 580GA and the lower capacitor group 580GB. As a result, the overlapping range of the P currents IpA and IpB flowing from capacitor groups 580GA and 580GB toward the upper switch group 530GA in the P busbar 601 and the output currents IoA and IoB flowing through the output busbar 603 can be extended as far as possible along CD. Similarly, the overlapping range of the N currents InA and InB flowing from the lower switch group 530GB toward capacitor groups 580GA and 580GB in the N busbar 602 and the output currents IoA and IoB flowing through the output busbar 603 can be extended as far as possible along CD. Therefore, in busbars 601 to 603, the range over which parasitic inductance can be reduced by the flow of currents IpA, IpB, InA, InB, IoA, and IoB can be made as wide as possible.

[0240] In this embodiment, busbars 601 to 603 are stacked so that their respective plate surfaces face each other. In this configuration, busbars 601 to 603 can be placed as close together as possible. Therefore, a configuration can be realized in which the magnetic fields generated by the P currents IpA, IpB and N currents InA, InB and the magnetic fields generated by the output currents IoA, IoB tend to cancel each other out.

[0241] According to this embodiment, the output busbar 603 is provided between the P busbar 601 and the N busbar 602. In this configuration, the P busbar 601 and the N busbar 602 can suppress the emission of radiated noise from the output busbar 603, such as electrostatic induction caused by potential fluctuations associated with power conversion. Moreover, since the potential fluctuations in the P busbar 601 and the N busbar 602 are relatively small, radiated noise due to electrostatic induction and the like is less likely to be emitted. Therefore, it is effective to shield the emitted noise from the output busbar 603 with the P busbar 601 and the N busbar 602, which are less likely to emit radiated noise. As described above, the EMC performance of the inverter device 80 can be improved by the arrangement of the busbars 601 to 603.

[0242] According to this embodiment, the earth busbar 604 is provided at the outermost position among the busbars 601 to 604. Therefore, the earth busbar 604 can suppress the emission of radiated noise due to electrostatic induction and the like from the P busbar 601, N busbar 602, and output busbar 603.

[0243] Furthermore, the earth busbar 604 is superimposed on the P busbar 601, N busbar 602, and output busbar 603. In this configuration, components connected to the P busbar 601, N busbar 602, and output busbar 603 can be placed closer to the earth busbar 604. Therefore, the connection path between these components and the earth busbar 604 can be shortened. For example, the Y capacitor section 527 can be connected to the earth busbar 604 in such a way that the ESL is low. ESL is the equivalent series inductance.

[0244] Furthermore, since the earth busbar 604 extends along the surface of the high-voltage substrate 510, the Y-capacitor section 527 can be connected to the earth busbar 604 at any point on the high-voltage substrate 510. This increases the degree of freedom regarding the installation position of the Y-capacitor section 527. In addition, the earth busbar 604 is electrically connected to the component support section 500 via multiple fasteners used to fix the high-voltage substrate 510 to the component support section 500. This reduces the parasitic impedance of the grounding path including the earth busbar 604. Thus, it is possible to achieve both improved EMC performance with the earth busbar 604 and enhanced protection against surges with the earth busbar 604.

[0245] In this embodiment, multiple P busbars 601, N busbars 602, and output busbars 603 are provided. As a result, magnetic fields due to currents IpA, IpB, InA, InB, IoA, and IoB are generated in each of the multiple busbars 601 to 603, making it possible to realize a configuration in which these magnetic fields tend to cancel each other out.

[0246] Furthermore, the P busbar 601 and N busbar 602 extend in an annular shape in the circumferential direction CD. In this configuration, since the P busbar 601 and N busbar 602 extend along the outer peripheral edge 512 of the high-voltage substrate 510, a closed circuit can be formed by the P line 141 and N line 142. When the P line 141 and N line 142 form a closed circuit in this way, the parasitic inductance between the upper arm 84 and the lower arm 85 tends to decrease. Therefore, losses occurring in the P line 141 and N line 142 can be reduced.

[0247] According to this embodiment, the output currents IoA and IoB flowing in the overlapping region AO are the currents flowing between the upper arm switch section 530A and the lower arm switch section 530B that form a single upper and lower arm circuit 83. Therefore, the parasitic inductance generated in a single upper and lower arm circuit 83 can be reduced by the flow of currents IpA, IpB, InA, InB, IoA, and IoB.

[0248] According to this embodiment, the output busbar 603 is connected to an upper source terminal 533A and a lower drain terminal 532B at positions spaced apart in the circumferential direction CD. In this configuration, it becomes possible to change the distance between the upper source terminal 533A and the lower drain terminal 532B. Therefore, the degree of freedom regarding the arrangement of the upper arm switch section 530A having the upper source terminal 533A and the lower arm switch section 530B having the lower drain terminal 532B can be increased.

[0249] Furthermore, in the circumferential CD, at least one of the upper drain terminal 532A and the P capacitor terminal 582, and at least one of the lower source terminal 533B and the low capacitor terminal are provided between the upper source terminal 533A and the lower drain terminal 532B. In this configuration, in the circumferential CD, the P currents IpA and IpB flow in opposite directions to the output currents IoA and IoB between the upper source terminal 533A and the lower drain terminal 532B. Also, in the circumferential CD, the N currents InA and InB flow in opposite directions to the output currents IoA and IoB between the upper source terminal 533A and the lower drain terminal 532B. Therefore, the magnetic fields generated by the output currents IoA and IoB cancel each other out, thereby reducing the parasitic inductances L601 to L603 on the busbars 601 to 603.

[0250] <Composition group C> According to this embodiment, multiple arm switch units 530 are arranged in the circumferential direction CD along the outer peripheral edges 512, 552 with respect to the high-voltage substrate 510 and the drive substrate 550. In this configuration, the positions of the multiple arm switch units 530 are aligned in the axial direction AD and the radial direction RD. Therefore, it is unlikely that the positional relationship between the arm switch units 530 and the high-voltage substrate 510 and the drive substrate 550 will vary among the multiple arm switch units 530. For example, the distance between the switch body 531 and the high-voltage substrate 510 in the radial direction RD is likely to be the same for each of the multiple arm switch units 530. Similarly, the distance between the switch body 531 and the drive substrate 550 in the radial direction RD is likely to be the same for each of the multiple arm switch units 530.

[0251] Therefore, it is difficult for the parasitic inductance generated in the current-carrying path including the terminals 532 to 533 to vary among the plurality of arm switch units 530, and it is also difficult for the switching accuracy to vary among the plurality of arm switch units 530. For example, it is difficult for the switching timing of the arm switch 86 to vary between the upper arm 84 and the lower arm 85, and it is also difficult for the switching timing to vary among the plurality of upper and lower arm circuits 83. Thus, since the decrease in the operation accuracy of the arm switch 86 is suppressed, the operation accuracy of the inverter device 80 can be enhanced.

[0252] As described above, the positions of the plurality of arm switch units 530 are aligned in the axial direction AD and the radial direction RD. For this reason, it is easy to make the separation distances between the switch body 531 and the substrates 510 and 550 uniform among the plurality of arm switch units 530. Therefore, it is possible to suppress the separation distance between the switch body 531 and the substrates 510 and 550 from becoming excessively large. In other words, the wiring length between the switch body 531 and the substrates 510 and 550 can be reduced. The wiring length is, for example, the length of the exposed portions 532ex to 535ex. When the wiring length is reduced, the parasitic inductance generated in the wiring is reduced. In the wiring, the surge voltage can be decreased by reducing the parasitic inductance. And, since the switching speed of the arm switch 86 can be increased by the amount by which the surge voltage has decreased, it becomes possible to reduce the loss.

[0253] In the inverter device 80 in which the plurality of arm switches 86 are connected in parallel, a phenomenon may occur in which the gate voltage Vg oscillates. When the balance of the currents flowing through the arm switches 86 is disrupted among the plurality of arm switches 86 connected in parallel, the gate voltage Vg is likely to oscillate. Also, the faster the switching speed of the arm switch 86, the more likely the oscillation of the gate voltage Vg becomes. On the other hand, the smaller the parasitic inductance of the wiring, the less likely the gate voltage Vg is to oscillate, so the switching speed of the arm switch 86 can be increased. Therefore, by reducing the parasitic inductance generated in the wiring, the switching speed of the arm switch 86 can be increased and the loss can be decreased.

[0254] In the inverter device 80, the higher the applied voltage from the battery 31, the more likely it is that losses due to parasitic inductance will occur. Also, the higher the switching speed of the arm switch 86, the more likely it is that losses due to parasitic inductance will occur. For this reason, even if at least one of the high voltage conversion and high speed switching of the inverter device 80 is performed, the plurality of arm switch units 530 are arranged in the circumferential direction CD along the outer peripheral ends 512, 552, so that the losses due to parasitic inductance can be reduced.

[0255] According to this embodiment, the switch body 531 is provided at a position closer to the high voltage substrate 510 than the drive substrate 550. For this reason, it is easy to realize a configuration in which the drain terminal 532 and the source terminal 533 are shorter than the gate terminal 534 and the driver source terminal 535. By shortening the power terminals such as the drain terminal 532 and the source terminal 533 in this way, the parasitic inductance generated by the power terminals can be reduced. Therefore, the losses generated by the power terminals can be reduced.

[0256] According to this embodiment, the drain exposed portion 532ex and the source exposed portion 533ex are shorter than the gate exposed portion 534ex and the driver source terminal 535. For this reason, the parasitic inductance generated by the power connection portions such as the drain exposed portion 532ex and the source exposed portion 533ex can be reduced. In this way, by reducing the parasitic inductance of the wiring by shortening the power connection portion, it is possible to increase the switching speed of the arm switch 86 and reduce the losses.

[0257] In this embodiment, the drain terminal 532 and the source terminal 533 are folded back. In this configuration, the magnetic fields generated by current flow cancel each other out at the two folded-back portions of the drain terminal 532 and the source terminal 533. Therefore, the parasitic inductance generated at the drain terminal 532 and the source terminal 533 can be reduced. For example, at the drain terminal 532 and the source terminal 533, the direction of the current flowing through the base extension 536a and the direction of the current flowing through the tip extension 536b are opposite. Therefore, the magnetic flux due to the current flowing through the base extension 536a and the magnetic flux due to the current flowing through the tip extension 536b cancel each other out. Consequently, the parasitic inductance generated at the base extension 536a and the tip extension 536b can be reduced.

[0258] According to this embodiment, since terminals 532 to 535 are connected to circuit boards 510 and 550, the connection structure between terminals 532 to 535 and circuit boards 510 and 550 can be simplified. Furthermore, since circuit boards 510 and 550 are plate-shaped, a configuration in which multiple arm switch sections 530 are arranged in a circumferential direction CD along the outer edges 512 and 552 can be easily realized.

[0259] According to this embodiment, the drain terminal 532 and source terminal 533 are positioned spaced apart from the substrate midline Cmid towards the high-voltage substrate 510. In this configuration, the drain terminal 532 and source terminal 533 can be spaced as far apart as possible from the drive substrate 550. Therefore, it is possible to suppress noise and other interference generated in the drive substrate 550 by the current flowing through the drain terminal 532 and source terminal 533. Consequently, the operating accuracy of the drive substrate 550 can be improved.

[0260] According to this embodiment, the high-voltage substrate 510 has power busbars such as a P busbar 601, an N busbar 602, and an output busbar 603. Therefore, the configuration to connect power terminals such as the drain terminal 532 and the source terminal 533 to the power busbars in a way that allows power to flow can be realized simply by connecting the power terminals to the high-voltage substrate 510. Thus, the configuration for connecting power terminals and power busbars can be simplified.

[0261] In this embodiment, the outer peripheral ends 512, 552 and the arm switch row 530R all extend in an annular shape along the circumferential direction CD. Therefore, at any position along the circumferential direction CD, the terminals 532 to 535 can be extended radially RD from the arm switch section 530 to connect to the high-voltage substrate 510 and the drive substrate 550. Consequently, variations in the length dimensions of the terminals 532 to 535 can be suppressed throughout the entire circumferential direction CD.

[0262] Furthermore, because the arm switch array 530R extends in an annular shape along the circumferential CD, the heat from multiple arm switch units 530 in the arm switch array 530R can be released radially outward across the entire circumferential CD. This prevents heat generated from the arm switch units 530 from accumulating in a part of the inverter outer periphery wall 91 and a part of the interior of the inverter housing 90.

[0263] According to this embodiment, the switch body 531 is provided on the inner circumferential surface 90b. In this configuration, it is not necessary to mount the switch body 531 on the high-voltage substrate 510 and the drive substrate 550. Therefore, the high-voltage substrate 510 and the drive substrate 550 can be made smaller by eliminating the need to mount the switch body 531. In other words, the substrate area of ​​the high-voltage substrate 510 and the drive substrate 550 can be reduced. By making the high-voltage substrate 510 and the drive substrate 550 smaller in the radial direction RD in this way, the inner diameter of the inverter housing 90 can be shortened. In other words, the inverter housing 90 and the inverter device 80 can be made smaller.

[0264] Furthermore, because the switch body 531 is located on the inner circumferential surface 90b, heat from the switch body 531 is easily transferred to the inner circumferential surface 90b. Therefore, the heat dissipation effect of the switch body 531 can be enhanced by the inverter outer circumferential wall 91.

[0265] In this embodiment, the heat dissipation from the second plate surface 531b of the switch body 531 is greater than the heat dissipation from the first plate surface 531a. In this configuration, the heat released radially inward from the first plate surface 531a is reduced, making it less likely for heat to accumulate inside the inverter housing 90. Moreover, the heat released radially outward from the second plate surface 531b tends to increase. As a result, the heat released from the switch body 531 to the outside via the inverter outer peripheral wall 91 tends to increase. Therefore, the heat dissipation effect of the inverter device 80 can be enhanced by the second plate surface 531b.

[0266] <Configuration group D> According to this embodiment, multiple arm switch units 530 are arranged in a circumferential direction CD relative to the inverter outer wall 91 and are in contact with the inner surface 90b. In this configuration, heat generated in each of the multiple arm switch units 530 is easily transferred directly from the switch body 531 to the inner surface 90b. Moreover, since the inverter outer wall 91 has an outer surface 90a, the heat transferred from the arm switch unit 530 to the inverter outer wall 91 is easily released to the outside from the outer surface 90a. Therefore, it is possible to suppress the temperature of the arm switch units 530 from becoming excessively high, and the transfer of heat generated from one arm switch unit 530 to other arm switch units 530. Consequently, the heat dissipation effect of the inverter device 80 can be enhanced. This makes it possible to suppress, for example, the occurrence of an abnormality due to an excessive rise in the temperature of the inverter device 80.

[0267] According to this embodiment, the smoothing capacitor section 580 and filter component 524, which generate less heat due to energization than the arm switch section 530, are positioned radially inward from the arm switch section 530. This configuration avoids the transfer of heat from the arm switch section 530 radially outward to the smoothing capacitor section 580 and filter component 524. In this case, it is less likely that the temperature of the smoothing capacitor section 580 and filter component 524 will rise due to the heat from the arm switch section 530. Furthermore, in this case, it is less likely that the heat from the arm switch section 530 will be prevented from reaching the inverter outer peripheral wall 91 by the smoothing capacitor section 580 and filter component 524. Therefore, the heat dissipation effect can be enhanced for each of the arm switch section 530, the smoothing capacitor section 580, and the filter component 524.

[0268] According to this embodiment, the arm switch array 530R extends in an annular shape in the circumferential direction CD. In this configuration, the heat from the multiple arm switch parts 530 of the arm switch array 530R can be released to the outside from the entire outer peripheral wall 91 of the inverter in the circumferential direction CD. Therefore, it is less likely that heat will accumulate in a part of the outer peripheral wall 91 of the inverter and a part of the internal space of the inverter housing 90. Consequently, it is possible to suppress, for example, the occurrence of an abnormality due to an excessive rise in the temperature of a part of the inverter device 80.

[0269] Furthermore, the capacitor row 580R and the filter row 524R extend in an annular shape along the circumferential CD radially inward from the arm switch row 530R. In this configuration, heat from the smoothing capacitor section 580 and the filter components 524 is less likely to accumulate in a part of the circumferential CD. Therefore, for example, it is possible to suppress the occurrence of an abnormality in the inverter device 80 due to an excessive temperature rise in a part of the circumferential CD located radially inward from the arm switch row 530R.

[0270] In this embodiment, a filter component 524, which generates less heat due to current flow than the smoothing capacitor section 580, is provided radially inward from the smoothing capacitor section 580. In this configuration, the positional relationship between the smoothing capacitor section 580 and the filter component 524 is set so that the heat generated on the central side of the inverter device 80 is minimized. As a result, heat is less likely to accumulate on the central side of the inverter device 80. Therefore, it is possible to suppress, for example, the occurrence of an abnormality due to an excessive rise in temperature on the central side of the inverter device 80.

[0271] According to this embodiment, the filter array 524R extends in an annular shape in the circumferential direction CD radially inward from the capacitor array 580R. In this configuration, heat from the filter component 524 is less likely to accumulate in a part of the circumferential direction CD radially inward from the capacitor array 580R. Therefore, it is possible to suppress, for example, a situation in which the temperature of a part of the inverter device 80 rises excessively in the central part of the inverter device 80, causing a malfunction in the inverter device 80.

[0272] According to this embodiment, the high-voltage substrate 510, as a plate member, is positioned radially inward from the inner surface 90b relative to the inverter outer peripheral wall 91. Therefore, by fixing the smoothing capacitor section 580 and the filter component 524 to the high-voltage substrate 510, a configuration in which the smoothing capacitor section 580 and the filter component 524 are positioned radially inward from the arm switch section 530 can be easily realized.

[0273] According to this embodiment, among the plurality of smoothing capacitor parts 580, the group arrangement part 580c is provided at a position arranged in the radial direction RD in the switch group 530G. In this configuration, since the group arrangement part 580c is arranged radially inside the arm switch part 530, the heat dissipation effect of the group arrangement part 580c is enhanced, and the separation distance between the switch group 530G and the group arrangement part 580c can be made as short as possible. For this reason, the energization path that energizes and connects the arm switch part 530 included in the switch group 530G and the group arrangement part 580c can be made as short as possible, such as making it the shortest path. Therefore, losses caused by parasitic inductance and the like in the energization path between the arm switch part 530 and the group arrangement part 580c can be reduced.

[0274] According to this embodiment, the inverter connector 96 is provided in the intermediate region Asw2 on the outer peripheral wall 91 of the inverter. For this reason, it is possible to avoid the situation where the heat dissipation of the arm switch part 530 from the outer peripheral wall 91 of the inverter in the switch region Asw1 is inhibited by the inverter connector 96. Therefore, it is possible to suppress the heat dissipation effect of the outer peripheral wall 91 of the inverter from being reduced by the inverter connector 96.

[0275] Moreover, among the plurality of filter parts 524, the connector arrangement part 524b is provided at a position arranged in the radial direction RD in the inverter connector 96. In this configuration, since the arm switch part 530 is not provided outside the connector arrangement part 524b in the radial direction, the heat of the connector arrangement part 524b easily escapes radially outward toward the inverter connector 96. For this reason, it is possible to suppress the heat of the filter part 524 from accumulating radially inside the arm switch part 530.

[0276] Furthermore, this configuration allows the distance between the inverter connector 96 and the connector and component 524b to be minimized. As a result, the power lines 570 and 571 connected to the connector and component 524b can be routed from the inverter connector 96 via the shortest possible route. In this way, the current path formed by the power lines 570 and 571, such as lines 141 and 142, can be made as short as possible, thereby reducing losses caused by parasitic inductance and other factors in lines 141 and 142.

[0277] In this embodiment, in the arm switch section 530, the second plate surface 531b of the switch body 531 is superimposed on the inner circumferential surface 90b. In this configuration, the heat transfer area from the switch body 531 to the inverter outer circumferential wall 91 can be made as large as possible. As a result, heat from the switch body 531 is more easily transferred to the inverter outer circumferential wall 91. The heat transfer effect from the switch body 531 to the inverter outer circumferential wall 91 can be enhanced.

[0278] According to this embodiment, in the switch body 531, the heat dissipation from the second panel surface 531b is greater than the heat dissipation from the first panel surface 531a. Therefore, as much heat as possible generated in the switch body 531 can be transferred to the inverter outer wall 91. Thus, a configuration can be achieved in which heat is easily transferred from the switch body 531 to the inverter outer wall 91.

[0279] According to this embodiment, in the arm switch section 530, heat from the switch body 531 is released to the outside through the first heat dissipation path PH1, and heat from the terminals 532 to 535 is released to the outside through the second heat dissipation path PH2 and the third heat dissipation path PH3. In this way, the heat from the arm switch section 530 is released to the outside of the inverter outer peripheral wall 91 through multiple paths, thereby enhancing the heat dissipation effect of the inverter device 80.

[0280] <Composition group B> <Second Embodiment> In the first embodiment described above, the output busbar 603 was provided between the P busbar 601 and the N busbar 602. In contrast, in the second embodiment, the output busbar 603 is not provided between the P busbar 601 and the N busbar 602. Configurations, operations, and effects not specifically described in the second embodiment are the same as in the first embodiment. The second embodiment will be described focusing on the differences from the first embodiment.

[0281] As shown in Figure 29, the P busbar 601 is provided between the N busbar 602 and the output busbar 603. The P busbar 601 is provided between the N busbar 602 and the output busbar 603 in both the first busbar set 611 and the second busbar set 612. For example, the output busbar 603 included in the first busbar set 611 is provided between the earth busbar 604 and the P busbar 601. The N busbar 602 included in the second busbar set 612 is provided between the P busbar 601 and the earth busbar 604.

[0282] In this embodiment as well, the connection relationship between the arm switch section 530 and the smoothing capacitor section 580 and the busbars 601 to 603 is the same as in the first embodiment, as shown in Figure 30. Also, the flow of currents IpA, IpB, InA, InB, IoA, and IoB in the busbars 601 to 603 is the same as in the first embodiment, as shown in Figures 31 and 32.

[0283] The order in which the P busbar 601, N busbar 602, and output busbar 603 are arranged may vary. For example, the order of busbars 601-603 may differ between the first busbar set 611 and the second busbar set 612. Also, adjacent busbars in the axial direction A and D may be of the same type. For example, two P busbars 601 may be located adjacent to each other in the axial direction A and D. Furthermore, there may be only one busbar set 611 or 612, or there may be three or more busbar sets. In addition, there may be multiple instances of at least one of the P busbar 601, N busbar 602, and output busbar 603.

[0284] <Third Embodiment> In the first embodiment described above, the upper capacitor section 580A and the lower capacitor section 580B were installed in opposite directions in the radial direction RD. In contrast, in the third embodiment, the upper capacitor section 580A and the lower capacitor section 580B are installed in the same direction in the radial direction RD. The configuration, operation, and effects of the third embodiment that are not specifically described above are the same as those of the first and second embodiments. The third embodiment will be described mainly in terms of the differences from the first and second embodiments.

[0285] As shown in Figure 33, in both the upper capacitor section 580A and the lower capacitor section 580B, the P capacitor terminal 582 is located radially outward from the N capacitor terminal 583. Both the upper P capacitor terminal 582A and the lower P capacitor terminal 582B are located radially outward from the upper N capacitor terminal 583A and the lower N capacitor terminal 583B.

[0286] In this embodiment, the distance over which the P currents IpA and IpB and the N currents InA and InB flow in the radial direction RD differs from that of the first embodiment. As shown in Figure 34, in the P busbar 601, both the upper P current IpA and the lower P current IpB flow from the P capacitor terminal 582, which is radially outward from the N capacitor terminal 583, to the upper drain terminal 532A. In the N busbar 602, both the upper N current InA and the lower N current InB that flow out from the lower source terminal 533B flow to the N capacitor terminal 583, which is radially inward from the P capacitor terminal 582. Therefore, the total distance over which the P currents IpA and IpB flow in the radial direction RD in the P busbar 601 is shorter than the total distance over which the N currents InA and InB flow in the radial direction RD in the N busbar 602.

[0287] Furthermore, the installation orientation of the smoothing capacitor section 580 may differ among the multiple smoothing capacitor sections 580 in a single capacitor group 580G. For example, in a single upper capacitor group 580GA, the installation orientation may differ among the multiple upper capacitor sections 580A. Also, the installation orientation of the smoothing capacitor section 580 may differ for each phase. For example, the installation orientation of the smoothing capacitor section 580 for the U phase and the smoothing capacitor section 580 for the V phase may differ. Moreover, the installation orientation of all smoothing capacitor sections 580 in the inverter device 80 may be the same.

[0288] In the smoothing capacitor section 580, the P capacitor terminal 582 and the N capacitor terminal 583 do not necessarily have to be aligned in the radial direction RD. For example, the P capacitor terminal 582 and the N capacitor terminal 583 may be aligned in the circumferential direction CD or in the axial direction AD. Also, the direction in which the P capacitor terminal 582 and the N capacitor terminal 583 extend from the capacitor body 581 does not necessarily have to be the axial direction AD. For example, the capacitor terminals 582 and 583 may extend in the circumferential direction CD or in the radial direction RD. Furthermore, the direction in which the P capacitor terminal 582 and the N capacitor terminal 583 extend from the capacitor body 581 may be different.

[0289] <Fourth Embodiment> In the first embodiment described above, multiple earth busbars 604 were provided for busbars 601 to 603. In contrast, in the fourth embodiment, only one earth busbar 604 is provided for busbars 601 to 603. Configurations, operations, and effects of the fourth embodiment that are not specifically described are the same as those of the first and second embodiments described above. The fourth embodiment will be described mainly in terms of the differences from the first and second embodiments described above.

[0290] As shown in Figure 35, the earth busbar 604 is provided at only one of a pair of outermost positions included in the plurality of plate-shaped conductors. The earth busbar 604 is provided, for example, only on the low-voltage side of the axial AD relative to busbars 601-603. The earth busbar 604 is not provided between busbars 601-603 and the capacitor body 581. The earth busbar 604 is provided on the opposite side of the capacitor body 581 via busbars 601-603 in the axial AD.

[0291] The earth busbar 604 may be located between busbars 601 to 603. For example, the earth busbar 604 may be located between P busbar 601 and N busbar 602. Also, the earth busbar 604 may be located between multiple busbar sets 611 and 612. For example, the earth busbar 604 may be located between the first busbar set 611 and the second busbar set 612.

[0292] <Composition group C> <Fifth Embodiment> In the first embodiment described above, the second plate surface 531b of the switch body 531 was superimposed on the inner circumferential surface 90b. In contrast, in the second embodiment, the base end portion 531c of the switch body 531 is superimposed on the inner circumferential surface 90b. Configurations, operations, and effects not specifically described in the fifth embodiment are the same as in the first embodiment. The fifth embodiment will be described mainly in terms of the differences from the first embodiment.

[0293] As shown in Figure 36, the plate-shaped switch body 531 extends in a direction perpendicular to the axial direction AD. In the switch body 531, the base end portion 531c is in contact with the inner circumferential surface 90b.

[0294] The switch body 531 is provided between the high-voltage substrate 510 and the drive substrate 550 in the axial direction AD. In the axial direction AD, the switch body 531 is located at a distance from both the high-voltage substrate 510 and the drive substrate 550. In this embodiment as well, the switch body 531 is located closer to the high-voltage substrate 510 than to the drive substrate 550. The switch body 531 may be located across the substrate midline Cmid in the axial direction AD, or it may be located at a distance from the substrate midline Cmid in the axial direction AD.

[0295] The entire switch body 531 is positioned between the first high-pressure surface 510a and the second control surface 550b in the axial direction AD. The switch body 531 does not protrude from the first high-pressure surface 510a toward the high-pressure side, nor from the second control surface 550b toward the low-pressure side, in the axial direction AD. The entire switch body 531 is included in the projected area obtained by projecting the substrate area radially outward.

[0296] Terminals 532 to 535 are bent into an L-shape overall. In terminals 532 to 535, the base extension 536a extends radially inward from the switch body 531. In the drain terminal 532 and source terminal 533, the tip extension 536b extends from the base extension 536a toward the high-voltage side in the axial direction AD. In the gate terminal 534 and driver source terminal 535, the tip extension 536b extends from the base extension 536a toward the low-voltage side in the axial direction AD.

[0297] <Sixth Embodiment> In the first embodiment described above, the arm switch unit 530 was a 4-terminal type switch module. In contrast, in the second embodiment, the multiple arm switch units 530 include both 4-terminal type switch modules and 6-terminal type switch modules. Configurations, operations, and effects not specifically described in the sixth embodiment are the same as in the first embodiment. The sixth embodiment will be described focusing on the differences from the first embodiment.

[0298] As shown in Figure 37, a 4-terminal arm switch section 530 and a 6-terminal arm switch section 530 are included in a plurality of arm switch sections 530. In this embodiment, a 4-terminal type switch module is referred to as a 4-terminal arm switch section 530. Similarly, a 6-terminal type switch module is referred to as a 6-terminal arm switch section 530. The 4-terminal arm switch section 530 and the 6-terminal arm switch section 530 are included in a single switch group 530G. In a single switch group 530G, the 4-terminal arm switch section 530 and the 6-terminal arm switch section 530 are electrically connected in parallel. A single switch group 530G includes, for example, a plurality of 4-terminal arm switch sections 530 and a plurality of 6-terminal arm switch sections 530.

[0299] The 6-terminal arm switch section 530 has an anode terminal 591 and a cathode terminal 592 in addition to terminals 532 to 535. The 6-terminal arm switch section 530 also has a temperature-sensing diode (not shown). The temperature-sensing diode is a temperature sensor that detects the temperature of the arm switch 86. The temperature-sensing diode can detect the temperature of the arm switch section 530. The anode terminal 591 is connected to the anode of the temperature-sensing diode. The cathode terminal 592 is connected to the cathode of the temperature-sensing diode. The anode terminal 591 and the cathode terminal 592 are detection terminals and are connected to the drive board 550 so that power can be supplied.

[0300] The anode terminal 591 and cathode terminal 592 are arranged in the width direction of the switch body 531 together with terminals 532 to 535. In this embodiment, the anode terminal 591 and cathode terminal 592 are arranged in the circumferential direction CD together with terminals 532 to 535. Note that terminals 532 to 535, 591, and 592 may or may not be offset in the radial direction RD.

[0301] <Seventh Embodiment> In the sixth embodiment described above, a single switch group 530G contained both a 4-terminal arm switch section 530 and a 6-terminal arm switch section 530. In contrast, in the second embodiment, a single switch group 530G contained only one of the 4-terminal arm switch section 530 or the 6-terminal arm switch section 530. The configuration, operation, and effects of the seventh embodiment that are not specifically described are the same as those of the sixth embodiment described above. The seventh embodiment will be described mainly in terms of the differences from the sixth embodiment described above.

[0302] As shown in Figure 38, of the 4-terminal arm switch section 530 and the 6-terminal arm switch section 530, only the 6-terminal arm switch section 530 is included in one switch group 530G.

[0303] Furthermore, all of the arm switch sections 530 of the inverter device 80 may be 6-terminal arm switch sections 530. Also, the multiple switch groups 530G of the inverter device 80 may include a switch group 530G having only 4-terminal arm switch sections 530 and a switch group 530G having only 6-terminal arm switch sections 530. In addition, the multiple switch groups 530G may include a switch group 530G having only one of the 4-terminal and 6-terminal arm switch sections 530 and a switch group 530G having both 4-terminal and 6-terminal arm switch sections 530.

[0304] <Eighth Embodiment> In the sixth embodiment described above, a plurality of arm switch units 530 included a 6-terminal type switch module. In contrast, in the eighth embodiment, a plurality of arm switch units 530 include a 7-terminal type switch module. Configurations, operations, and effects of the eighth embodiment that are not specifically described are the same as those of the first embodiment described above. The eighth embodiment will be described focusing on the differences from the first embodiment described above.

[0305] As shown in Figure 39, a 7-terminal arm switch unit 530 is included in multiple arm switch units 530. In this embodiment, a 7-terminal type switch module is referred to as a 7-terminal arm switch unit 530. Multiple 7-terminal arm switch units 530 are included in one switch group 530G. For example, one switch group 530G contains only 7-terminal arm switch units 530.

[0306] The 7-terminal arm switch section 530 has a sense source terminal 593 in addition to terminals 532-535, 591, and 592. The 7-terminal arm switch section 530 also has a current detection unit (not shown). This current detection unit is capable of detecting the current flowing through the arm switch 86. The sense source terminal 593 is connected to the current detection unit. The sense source terminal 593 is a detection terminal and is connected to the drive board 550 so that it can conduct electricity.

[0307] The sense source terminal 593 is arranged in the width direction of the switch body 531 together with terminals 532-535, 591, and 592. In this embodiment, the sense source terminal 593 is arranged in the circumferential direction CD together with terminals 532-535, 591, and 592. Note that terminals 532-535 and 591-593 may or may not be offset in the radial direction RD.

[0308] Furthermore, all of the multiple arm switch units 530 in the inverter device 80 may be 7-terminal arm switch units 530. Also, the multiple arm switch units 530 in the inverter device 80 may include multiple types of arm switch units 530. For example, the multiple arm switch units 530 may include at least one each of 4-terminal, 6-terminal, and 7-terminal arm switch units 530. Moreover, a single switch group 530G may include multiple types of arm switch units 530. For example, a single switch group 530G may include at least one each of 4-terminal, 6-terminal, and 7-terminal arm switch units 530.

[0309] <Other Embodiments> The disclosure in this specification is not limited to the exemplary embodiments. The disclosure encompasses the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and elements shown in the embodiments, but can be implemented in various variations. The disclosure can be implemented in a variety of combinations. The disclosure may have additional parts that can be added to the embodiments. The disclosure encompasses embodiments in which parts and elements have been omitted. The disclosure encompasses substitutions or combinations of parts and elements between one embodiment and another. The scope of the disclosed technical field is not limited to the descriptions of the embodiments. The scope of the disclosed technical field is indicated by the claims and should be understood to include all modifications within the meaning and scope equivalent to the claims.

[0310] <Composition group A> In each of the above embodiments, the multiple beam sections 501 may be located at any position in the circumferential direction CD and the axial direction AD, as long as they are arranged in multiple directions in the circumferential direction CD. For example, the beam section 501 may be located closer to the low-pressure side end than the high-pressure side end on the inverter outer wall 91, or closer to the high-pressure side end than the low-pressure side end. Also, the beam section 501 may be located in a position that overlaps with the inverter fins 92 in the radial direction RD.

[0311] In each of the above embodiments, the beam connecting portion 502 does not have to be annular, as long as it connects a plurality of beam portions 501. For example, the beam connecting portion 502 does not have to have a connecting opening 504. The plate member, such as the high-voltage substrate 510, does not have to be fixed to the beam connecting portion 502, as long as it is fixed to the beam portion 501. The component support portion 500 does not have to have a beam connecting portion 502, as long as it has beam portions 501. For example, the component support portion 500 may have a plurality of beam portions 501 that are independent of each other. Even in this case, the plate member, such as the high-voltage substrate 510, is fixed across the plurality of beam portions 501. The plate member is fixed to at least one beam portion 501.

[0312] In each of the above embodiments, the beam portion 501 and the inverter outer wall 91 do not have to be integrally molded. For example, the beam portion 501 may be attached to the inverter outer wall 91 afterwards. Also, the beam portion 501 and the inverter outer wall 91 do not have to be electrically conductive. For example, at least one of the beam portion 501 and the inverter outer wall 91 may not have electrical conductivity or have low electrical conductivity. Furthermore, the beam portion 501 and the inverter outer wall 91 do not have to be heat-transferable. For example, at least one of the beam portion 501 and the inverter outer wall 91 may not have thermal conductivity or have low thermal conductivity.

[0313] In each of the above embodiments, the two plate members facing each other via the beam portion 501 may be circuit boards. For example, the control board 560 may be stretched across multiple beam portions 501 and fixed to multiple beam portions 501. Also, both of the two plate members facing each other via the beam portion 501 may be high-voltage boards 510, or low-voltage boards such as the drive board 550. The drive board 550 and the control board 560 may be integrated.

[0314] In each of the above embodiments, the plate members stretched across and fixed to the multiple beam sections 501 do not have to be circuit boards such as the high-voltage substrate 510. For example, an insulating glass plate material may be used as the plate member, stretched across and fixed to the multiple beam sections 501. Also, at least one of the first plate member such as the high-voltage substrate 510 and the second plate member such as the drive substrate 550 may be a plate member that is not a circuit board.

[0315] In each of the above embodiments, the plate member such as the high-voltage substrate 510 fixed to the beam portion 501 does not have to be annular. For example, it may be a plate member without an opening such as a substrate opening 513. Also, the plate member such as the high-voltage substrate 510 may be provided on only one side of the beam portion 501 in the axial direction AD. In the axial direction AD, at least one of the beam portion 501 may have multiple plate members arranged along the beam portion 501 in at least one direction of the radial direction RD and the circumferential direction CD.

[0316] In each of the above embodiments, the arm switch section 530 may be located on the lower-voltage side of the beam section 501, as long as it is positioned offset from the beam section 501 in the axial direction AD. Alternatively, the arm switch section 530 may be located in a position that overlaps with the beam section 501 in the axial direction AD. For example, the arm switch section 530 and the beam section 501 may be arranged in the circumferential direction CD. Furthermore, at least a portion of the arm switch section 530 may be located in a position that overlaps with a plate member such as the high-voltage substrate 510 in the axial direction AD. For example, a portion of the arm switch section 530 may be positioned between the high-voltage substrate 510 and the drive substrate 550.

[0317] In each of the above embodiments, the switch body 531 does not have to be oriented so that its plate surfaces 531a and 531b are perpendicular to the radial direction RD. For example, the switch body 531 may be provided with its plate surfaces 531a and 531b oriented perpendicular to the axial direction AD. Alternatively, the switch body 531 may be provided with its plate surfaces 531a and 531b oriented perpendicular to the circumferential direction CD.

[0318] In each of the above embodiments, the switch body 531 may be fixed to at least one of a plate member such as a high-voltage substrate 510 and the inverter outer peripheral wall 91. For example, the switch body 531 may be fixed to the high-voltage substrate 510. Alternatively, the switch body 531 may be provided at a position spaced radially inward from the inverter outer peripheral wall 91. In these configurations as well, if the multiple arm switch sections 530 are arranged along the inner circumferential surface 90b, heat from the arm switch sections 530 is easily transferred to the inverter outer peripheral wall 91.

[0319] In each of the above embodiments, the multiple arm switch units 530 may be arranged in multiple rows in the circumferential direction CD, rather than in a single row. The multiple rows may be arranged in the axial direction AD, or in the radial direction RD. For example, the multiple arm switch units 530 of one switch group 530G may be arranged in two rows. Alternatively, two switch groups 530G having multiple arm switch units 530 arranged in a single row may be arranged in the axial direction AD. Furthermore, the multiple arm switch units 530 may be arranged as a power module by assembling them in a plane, forming a plane on the inner circumferential surface 90b and placing them there.

[0320] In each of the above embodiments, the switch group 530G may be provided at a position that overlaps with the beam portion 501 in the circumferential direction CD. For example, one switch group 530G may be provided at a position that straddles the beam portion 501 in the circumferential direction CD. Alternatively, one switch group 530G may be provided across two adjacent beam portions 501 in the circumferential direction CD.

[0321] <Composition group B> In each of the above embodiments, the upper arm switch section 530A and the lower arm switch section 530B do not necessarily have output control terminals such as the driver source terminal 535. For example, as shown in Figure 22, the drive power supply 620 may be configured to apply a control voltage to the source terminal 533 and the gate terminal 534. That is, the arm switch section 530 may be a 3-terminal type switch module. This arm switch section 530 has a drain terminal 532, a source terminal 533, and a gate terminal 534, but does not have a driver source terminal 535. Even if the first switch section 530A1 and the second switch section 530A2 are of the 3-terminal type, as in the first embodiment, a difference between inductance Ls1 and inductance Ls2 will easily cause current imbalance. Therefore, even if the first switch section 530A1 and the second switch section 530A2 are of the 3-terminal type, as in the first embodiment, current imbalance can be suppressed by reducing the inductance L603.

[0322] In each of the above embodiments, the upper arm switch section 530A and the lower arm switch section 530B may be provided in any way, as long as a high-potential current such as the upper P current IpA, a low-potential current such as the upper N current InA, and an output current such as the upper output current IoA flow in the overlapping region AO. For example, the upper arm switch section 530A and the lower arm switch section 530B may be provided at positions offset in the axial direction AD and the radial direction RD. Also, the upper arm switch section 530A and the lower arm switch section 530B may be provided one at a time, rather than multiple of each. The upper arm switch section 530A and the lower arm switch section 530B may be provided on the substrates 510, 550, 560, and the component support section 500, etc. The upper arm switch section 530A and the lower arm switch section 530B may be provided at positions spaced radially inward from the inner circumferential surface 90b.

[0323] In each of the above embodiments, if a high-potential current such as the upper P current IpA, a low-potential current such as the upper N current InA, and an output current such as the upper output current IoA flow through the overlapping region AO, the capacitor components such as the smoothing capacitor section 580 may be provided in any manner. For example, the smoothing capacitor section 580 may be provided at a position spaced apart from the upper arm switch section 530A and the lower arm switch section 530B in the circumferential direction CD and the axial direction AD. The smoothing capacitor section 580 may be provided at a position spaced apart from the overlapping region AO. Only one smoothing capacitor section 580 may be provided for the upper arm switch section 530A and the lower arm switch section 530B. The capacitor component does not have to be the smoothing capacitor section 580. For example, the X capacitor section 528 may be provided as the capacitor component.

[0324] In each of the above embodiments, the extension direction of the busbars 601 to 603 does not have to be the circumferential direction CD. For example, if the busbars 601 to 603 are provided on a portion of the inverter outer periphery wall 91 that extends linearly in a predetermined direction, the extension direction of the busbars 601 to 603 will be the predetermined direction. The direction in which the busbars 601 to 603 are stacked may be the circumferential direction CD and the radial direction RD, etc.

[0325] In each of the above embodiments, the high-potential conductor, low-potential conductor, and output conductor do not have to be busbars, as long as they are conductors. Also, the high-potential conductor, low-potential conductor, and output conductor do not have to be plate-shaped, as long as they extend along each other.

[0326] In each of the above embodiments, it is sufficient that at least one of the high-potential conductor and the low-potential conductor extends along the output conductor. For example, a configuration in which only one of the high-potential conductor and the low-potential conductor extends along the output conductor. In this configuration as well, in the overlapping region AO through which output currents IoA and IoB flow, it is sufficient that one of the P currents IpA and IpB and the N currents InA and InB flows in the opposite direction to the output currents IoA and IoB in the circumferential direction CD. In this configuration, the smoothing capacitor section 580 corresponds to a parallel component, and one of the P currents IpA and IpB and the N currents InA and InB corresponds to a parallel current. Also, one of the P busbar 601 and the N busbar 602 corresponds to a power conductor.

[0327] In this configuration, in the overlapping region AO, the parallel current flowing through one of the P busbar 601 and N busbar 602 is in the opposite direction in the circumferential direction CD to the output currents IoA and IoB flowing through the output busbar 603. As a result, the magnetic field generated by the parallel current and the magnetic field generated by the output currents IoA and IoB cancel each other out, thereby reducing the parasitic inductance in one of the P busbar 601 and N busbar 602 and in the output busbar 603.

[0328] <Composition group C> In each of the above embodiments, the main body heat dissipation section 538 may be provided at any part of the switch body 531. However, it is preferable that the main body heat dissipation section 538 is provided at a part of the switch body 531 that is in contact with the inverter outer peripheral wall 91. For example, in a configuration in which the base end portion 531c of the switch body 531 is in contact with the inner peripheral surface 90b, it is preferable that the main body heat dissipation section 538 is provided at the base end portion 531c so as to be in contact with the inner peripheral surface 90b.

[0329] In each of the above embodiments, power terminals such as the drain terminal 532 may straddle the substrate intermediate line Cmid in the axial direction A and D. For example, in a configuration where the switch body 531 is on the lower voltage side of the substrate intermediate line Cmid, the power terminals will straddle the substrate intermediate line Cmid in the axial direction A and D. Also, control terminals such as the gate terminal 534 do not have to straddle the substrate intermediate line Cmid in the axial direction A and D. For example, in a configuration where the switch body 531 is on the lower voltage side of the substrate intermediate line Cmid, the control terminals can be positioned on the lower voltage side of the substrate intermediate line Cmid.

[0330] In each of the above embodiments, the switch body 531 may be provided in any orientation. The switch body 531 may be provided in an orientation perpendicular to the axial direction AD, as shown in Figure 36, or in an orientation perpendicular to the circumferential direction CD.

[0331] In each of the above embodiments, the position in which the switch body 531 is provided does not have to be closer to the high-voltage substrate 510 than to the drive substrate 550. For example, the switch body 531 may be provided in a position closer to the drive substrate 550 than to the high-voltage substrate 510. Also, the portion of the switch body 531 provided between the first high-voltage surface 510a and the second control surface 550b in the axial direction AD does not have to be the base end portion 531c of the body. For example, the projected region obtained by projecting the substrate region radially outward may include at least the tip portion 531d of the body.

[0332] In each of the above embodiments, if the multiple arm switch sections 530 are arranged in the circumferential direction CD along the outer peripheral ends 512, 552, the switch body 531 does not have to be provided on the inner circumferential surface 90b. For example, the switch body 531 may be provided at a position spaced radially inward from the inner circumferential surface 90b. Also, the switch body 531 may be provided on at least one of the high-voltage substrate 510 and the drive substrate 550. However, from the viewpoint of suppressing a decrease in the operating accuracy of the drive substrate 550 due to noise from the switch body 531, it is preferable that the switch body 531 is not provided on the drive substrate 550.

[0333] In each of the above embodiments, the power outer ends such as the outer end 512 and the control outer ends such as the outer end 552 may extend intermittently in the circumferential direction CD. One example of a configuration in which the power outer ends and control outer ends extend intermittently in the circumferential direction CD is one in which multiple recesses that are recessed radially inward are arranged along the circumferential direction CD at the power outer ends and control outer ends. In this configuration as well, if the power terminals such as the drain terminal 532 are connected between two adjacent recesses in the circumferential direction CD at the power connection target such as the high-voltage substrate 510, variations in the lengths of the multiple power terminals can be suppressed. Similarly, if the control terminals such as the gate terminal 534 are connected between two adjacent recesses in the circumferential direction CD at the control connection target such as the drive substrate 550, variations in the lengths of the multiple control terminals can be suppressed.

[0334] In each of the above embodiments, the power outer end and the control outer end do not have to be annular as long as they extend in the circumferential direction CD. For example, multiple power outer ends and control outer ends may be arranged in the circumferential direction CD. Similarly, the arm switch row 530R does not have to be annular as long as it extends in the circumferential direction CD. For example, multiple arm switch rows 530R may be arranged in the circumferential direction CD.

[0335] In each of the above embodiments, the power connection target and the control connection target do not have to be a circuit board. For example, the P busbar 601, N busbar 602, and output busbar 603, which are power connection targets, may be provided independently of the high-voltage board 510. Also, the power connection target and the control connection target do not have to be aligned in the axial direction A and D. For example, the control connection target may be provided radially inward of the power connection target.

[0336] <Configuration group D> In each of the above embodiments, any part of the arm switch section 530 may be fixed to the inverter outer wall 91, as long as heat can be transferred between the arm switch section 530 and the inverter outer wall 91. For example, in the switch body 531, at least one of the base end 531c and the tip end 531d of the body may be fixed to the inner surface 90b. Also, in the arm switch section 530, terminals 532 to 535 may be fixed to the inverter outer wall 91.

[0337] In each of the above embodiments, in a single row of arm switch rows 530R, it is sufficient that a predetermined number of arm switch units 530 are arranged in the circumferential direction CD in at least a portion of the circumferential direction CD. Furthermore, the arm switch rows 530R may consist of more than one row. For example, two rows of arm switch rows 530R may be arranged in the axial direction AD. In the arm switch row 530R, multiple arm switch units 530 may be arranged at equal intervals. For example, the arm switch units 530 may be arranged regardless of the positions of the inverter fins 92 and the beam units 501. Furthermore, the arm switch row 530R does not have to be annular. For example, the arm switch row 530R may be provided only in a portion of the circumferential direction CD relative to the inverter outer peripheral wall 91. Moreover, if multiple arm switch units 530 are arranged in the circumferential direction CD, these arm switch units 530 do not necessarily form an arm switch row 530R.

[0338] These modifications relating to the arm switch array 530R may also be applied to the capacitor array 580R and the filter array 524R. For example, in a configuration where there are two capacitor arrays 580R, the two capacitor arrays 580R may be arranged radially RD.

[0339] In each of the above embodiments, the arm switch unit 530 may be directly fixed to the inverter outer wall 91 or indirectly fixed, as long as it is in contact with the inner circumferential surface 90b. An example of a configuration in which the arm switch unit 530 is directly fixed to the inverter outer wall 91 is the configuration in which the switch body 531 is fixed to the inner circumferential surface 90b with an adhesive or the like, as in the first embodiment above. Alternatively, even if the switch body 531 is not fixed to the inner circumferential surface 90b, it can be fixed to the inverter outer wall 91 via terminals 532-535, circuit boards 510, 550 and component support part 500. In other words, the arm switch unit 530 is indirectly fixed to the inverter outer wall 91 via the high-voltage circuit board 510, drive circuit board 550 and component support part 500.

[0340] In each of the above embodiments, the filter array 524R only needs to include at least one type of filter component 524. For example, the filter array 524R may be formed by including at least one of a common mode coil section 525, a normal mode coil section 526, a Y capacitor section 527, and an X capacitor section 528.

[0341] In each of the above embodiments, in the array of small heat-generating components, the filter array 524R may be provided radially outward from the capacitor array 580R. Also, in one array of small heat-generating components, the smoothing capacitor section 580 and the filter component 524 may be mixed together. Furthermore, the plate member on which the array of small heat-generating components such as the capacitor array 580R is provided does not have to be a high-voltage substrate 510, and may not even be a circuit board. For example, the capacitor array 580R may be provided on a glass plate.

[0342] <Common> In each of the above embodiments, the cover member, such as the inverter cover portion 99, may be provided on at least one of the high-pressure side and the low-pressure side of the inverter housing 90. The cover member may be made of a thick plate material or a thin plate material. The cover member may have thermal insulation properties. For example, in a configuration where a thermally insulating cover member is provided between the motor housing 70 and the inverter housing 90, the heat from the motor device 60 is suppressed from being transferred to the inverter device 80 by the cover member. If the cover member on the opposite side of the motor housing 70 is made of a material with good thermal conductivity, such as aluminum, heat dissipation to the outside of the inverter can be promoted. In this configuration, the cooling effect of the inverter device 80 can be enhanced by the cover member. Furthermore, the cover member does not have to be provided on either the high-pressure side or the low-pressure side of the inverter housing 90.

[0343] In each of the above embodiments, if heat is released to the outside from the outer surface 90a or the cover member, the inverter fins 92 do not need to be provided on the inverter outer wall 91. Alternatively, a water cooling passage may be provided instead of the inverter fins 92. Furthermore, the inverter housing 90 does not have to be annular as long as it is formed in an annular shape as a whole. For example, the inverter outer wall 91 does not need to be annular in plan view, but rather polygonal in plan view. Preferably, this polygon is a polygon with five or more sides.

[0344] In each of the above embodiments, the EPU 50 may have multiple motor units 60 and inverter units 80. For example, as shown in Figure 40, one EPU 50 may have two motor units 60 and two inverter units 80. In a configuration in which the EPU 50 has multiple motor units 60 and inverter units 80, all motor units 60 and all inverter units 80 may be arranged in the axial direction A and D. In this configuration, for example, as shown in Figure 40, the motor units 60 and inverter units 80 may be arranged alternately. Also in this configuration, two motor units 60 may be arranged adjacent to each other in the axial direction A and D, and two inverter units 80 may be arranged adjacent to each other in the axial direction A and D. Furthermore, an inverter unit 80 may be sandwiched between multiple motor units 60, or one or more motor units 60 may be sandwiched between multiple inverter units 80.

[0345] It is preferable that the motor unit 60 and the inverter unit 80 are configured to be easily stacked in the axial direction AD. For example, in a configuration in which multiple inverter units 80 are stacked in the axial direction AD, it is preferable that the outer peripheral walls 91 of each inverter are the same shape and size in a plan view. This makes it possible to accommodate design changes such as improved redundancy, increased output, and multi-phase configuration of the EPU 50 using the motor unit 60 and the inverter unit 80. Furthermore, in the EPU 50, the motor unit 60 and the inverter unit 80 may be arranged radially RD.

[0346] In each of the above embodiments, at least one EPU 50 may be provided for a drive target such as a wheel or rotor blade. For example, multiple EPUs 50 may be provided for a single drive target. As shown in Figure 41, two EPUs 50 may be provided for a single reduction gear 53. Multiple EPUs 50 may be arranged in a radial direction RD.

[0347] In each of the above embodiments, the motor electromagnetic circuit 61 may be a radial gap type motor. In this motor electromagnetic circuit 61, for example, the stator is provided radially outward from the rotor. The rotor may be either an inner type or an outer type.

[0348] [Feature A1] A power converter (80) that converts electricity, Case (90) having an outer peripheral wall (91) that extends in a ring shape, Multiple beam sections (501) extend inward from the outer wall in the radial direction (RD) of the outer wall and are arranged in multiple directions in the circumferential direction (CD) of the outer wall, Plate members (510, 550) extend in a plate-like shape in a direction perpendicular to the axial direction (AD) of the outer wall and are fixed to multiple beam sections while being spanned across multiple beam sections, It is electrically conductive and the mounted components (146, 147, 525~528, 580) are mounted on the plate member, A power converter equipped with the following features.

[0349] [Feature A2] As plate members, a first plate member (510) is provided on one side of the beam portion in the axial direction, As a plate member, a second plate member (550) is provided on the opposite side from the first plate member via a beam in the axial direction, A power conversion device as described in Feature A1, which is equipped with the features described above.

[0350] [Feature A3] The first plate member is a high-voltage substrate (510) to which a high voltage is applied. The power conversion device according to feature A2, wherein the second plate member is a low-voltage substrate (550) to which a low voltage lower than the high voltage is applied.

[0351] [Feature A4] A power conversion device according to any one of features A1 to A3, comprising a conversion switch (86) for converting power, a plurality of switch components (530) arranged circumferentially along the outer peripheral edges (512, 552) of a plate member and fixed to the inner circumferential surface (90b) of the outer peripheral wall.

[0352] [Feature A5] The plate member comprises a plurality of switch groups (539) arranged circumferentially along the outer edge, each having a plurality of switch components arranged circumferentially. The power converter according to feature A4, wherein the beam section extends inward from the outer wall between two circumferentially adjacent switch groups.

[0353] [Feature A6] The switch component comprises a switch body (531) having a switch element and switch terminals (532-535) extending from the switch body. The power conversion device described in feature A4 or A5, wherein the switch body is installed at a position spaced apart from the beam and plate members.

[0354] [Feature A7] It is equipped with heat dissipation fins (92) that extend radially outward from the outer periphery wall and release heat to the outside, The power conversion device according to any one of features A4 to A6, wherein the switch component is positioned in a radial direction, aligned with the heat dissipation fins.

[0355] [Feature A8] The power conversion device according to features A1 to A7, comprising a beam connecting section (502) provided at a position spaced radially inward from the outer perimeter wall and connecting multiple beam sections.

[0356] [Feature A9] The beam connection section extends in a ring shape in the circumferential direction, as described in Feature A8 of the power conversion device.

[0357] [Feature A10] A power conversion device that allows heat transfer between the beam section and the outer wall, as described in any one of features A1 to A9.

[0358] [Feature A11] A power conversion device described in any one of the features A1 to A10, wherein the beam section and the outer wall are electrically connected.

[0359] [Feature A12] A rotating electric machine unit (50) that is driven by the supply of electricity, A rotating electric machine (60) having a rotor (300) and a stator (200), A power conversion device (80) that converts the power supplied to a rotating electric machine, Equipped with, Power converters are It has an annular outer wall (91) and a case (90) that is fixed to a rotating electric machine, Multiple beam sections (501) extend inward from the outer wall in the radial direction (RD) of the outer wall and are arranged in multiple directions in the circumferential direction (CD) of the outer wall, Plate members (510, 550) extend in a plate-like shape in a direction perpendicular to the axial direction (AD) of the outer wall and are fixed to multiple beam sections while being spanned across multiple beam sections, It is electrically conductive and the mounted components (146, 147, 525~528, 580) are mounted on the plate member, A rotating electric machine unit having the following features.

[0360] [Feature A13] In the power conversion device, the outer perimeter wall is the outer perimeter wall (91) of the device. Rotating electric machines are, An annularly extending electrical outer wall (71) housing the rotor and stator, arranged axially on the outer wall of the device, A cover portion (62) fixed to the outer wall of the electric machine, covering the rotor and stator from the outer wall side of the device, It has, Power converters are The rotating electric machine unit according to feature A12, having an insulating part (545) provided between the plate member and the cover part, extending along the cover part, and having heat insulating properties.

[0361] [Feature A14] A power conversion device or inverter device (80) that converts electricity, The case (90) has an annular outer wall (91), a transistor switch (530) inside the outer wall, and cooling fins (92) outside the outer wall. Multiple beam sections (501) extend inward from the outer wall in the radial direction (RD) of the outer wall and are arranged in multiple directions in the circumferential direction (CD) of the outer wall, Plate members (510, 550) extend in a plate-like shape in a direction perpendicular to the axial direction (AD) of the outer wall and are fixed to multiple beam sections while being spanned across multiple beam sections, The mounted components (146, 147, 525~528, 580) attached to the plate member, It is a power conversion device equipped with [a specific feature / ability].

[0362] [Feature A15] A rotating electric machine unit (50) that is driven by the supply of electricity, A rotating electric machine (60) having a rotor (300) and a stator (200), A power conversion device (80) that converts the power supplied to a rotating electric machine, Equipped with, Power converters are A power conversion device or inverter device (80) that converts electricity, The case (90) has an annular outer wall (91), a transistor switch (530) inside the outer wall, and cooling fins (92) outside the outer wall. Multiple beam sections (501) extend inward from the outer wall in the radial direction (RD) of the outer wall and are arranged in multiple directions in the circumferential direction (CD) of the outer wall, Plate members (510, 550) extend in a plate-like shape in a direction perpendicular to the axial direction (AD) of the outer wall and are fixed to multiple beam sections while being spanned across multiple beam sections, The mounted components (146, 147, 525~528, 580) attached to the plate member, This is a rotating electric machine unit equipped with [a specific feature / feature].

[0363] [Feature B1] A power converter (80) that converts electricity, A high-potential conductor (601) extends in the direction of extension (CD) and is supplied with power on the high-potential side, A low-potential conductor (602) extends in the direction of extension along the high-potential conductor and is supplied with power on the low-potential side, An output conductor (603) extends in the direction of extension along the high-potential conductor and the low-potential conductor, and outputs power, The upper switch component (530A) on the high-potential side, which switches to convert power, The lower switch component (530B) on the low-potential side switches to convert power, Capacitor components (580, 580A, 580B) are electrically connected in parallel to the upper and lower switch components, Equipped with, The output conductor is connected such that the output current (IoA, IoB) flows through the output conductor in the direction extending from the upper switch component to the lower switch component, with the upper and lower switch components spaced apart from each other in the direction extending. In the high-potential conductor, the capacitor component and the upper switch component are connected such that, in the overlapping region (AO) that overlaps with the output current in the extension direction, a high-potential current (IpA, IpB) flows in the high-potential conductor from the capacitor component toward the upper switch component in the opposite direction to the output current. A power converter in which a low-potential conductor is connected to a lower switch component and a capacitor component such that, in the overlapping region, a low-potential current (InA, InB) flows through the low-potential conductor from the lower switch component to the capacitor component in the opposite direction to the output current.

[0364] [Feature B2] The power converter according to feature B1, wherein multiple upper switch components in one phase and multiple lower switch components in one phase are arranged in an elongated direction along a high-potential conductor, a low-potential conductor, and an output conductor.

[0365] [Feature B3] The case (90) comprises an outer peripheral wall (91) that extends in an annular manner in the circumferential direction (CD) as the direction of extension, The high-potential conductor, low-potential conductor, and output conductor extend circumferentially along the inner surface (90b) of the outer wall. The power converter according to feature B1 or B2, wherein multiple upper switch components included in one phase and multiple lower switch components included in one phase are arranged circumferentially along the inner surface.

[0366] [Feature B4] The power conversion device according to feature B3, wherein the upper and lower switch components are located radially (RD) spaced outward from the high-potential conductor, low-potential conductor, and output conductor, and are provided on the inner circumferential surface.

[0367] [Feature B5] As a capacitor component, an upper capacitor component (580A) is provided at a position aligned with the upper switch component in the radial direction (RD) of the outer wall, and spaced radially inward from the upper switch component, As a capacitor component, a lower capacitor component (580B) is provided at a position aligned radially with the lower switch component, and spaced radially inward from the lower switch component, Equipped with, The upper and lower capacitor components have a high-potential capacitor terminal (582) connected to a high-potential conductor and a low-potential capacitor terminal (583) connected to a low-potential conductor. The power conversion device according to feature B3 or B4, wherein in one of the upper capacitor component and the lower capacitor component, the high capacitor terminal is provided radially outward from the low capacitor terminal, and in the other, the low capacitor terminal is provided radially outward from the high capacitor terminal.

[0368] [Feature B6] An upper switch group (530GA) having multiple upper switch components included in one phase and arranged in the trajectory, A lower switch group (530GB) having multiple lower switch components arranged in the extension direction in the upper switch group, and included in the same phase as the multiple upper switch components of the upper switch group and arranged in the extension direction, Equipped with, The power converter according to any one of features B1 to B5, wherein the overlapping region is a region that extends in the direction of extension, spanning between the furthest upper component (530Af) of the upper switch group that is furthest from the lower switch group among the multiple upper switch components of the upper switch group, and the furthest lower component (530Bf) of the lower switch group that is furthest from the upper switch group among the multiple lower switch components of the lower switch group.

[0369] [Feature B7] A first capacitor group (580GA) having a plurality of first capacitor components (580A) arranged in the extension direction and aligned with the upper switch component in an orthogonal direction (RD) perpendicular to the extension direction, A second capacitor group (580GB) having a plurality of second capacitor components (580B) arranged in the orthogonal direction to the lower switch component and in the extension direction, Equipped with, The power converter according to any one of features B1 to B6, wherein the overlapping region extends in the direction of extension so as to span across the first capacitor group and the second capacitor group.

[0370] [Feature B8] A power conversion device according to any one of features B1 to B7, wherein a high-potential conductor, a low-potential conductor, and an output conductor are each formed in a plate shape, and their respective plate surfaces are stacked facing each other.

[0371] [Feature B9] It comprises a plurality of plate-shaped conductors (601-604) that are conductive, formed in a plate shape, and stacked so that their respective plate surfaces face each other, Multiple plate-shaped conductors include a high-potential conductor, a low-potential conductor, and an output conductor. The power conversion device according to any one of features B1 to B8, wherein the output conductor is provided between the first plate portion (601) and the second plate portion (602) of a plurality of plate-shaped conductors.

[0372] [Feature B10] The multiple plate-shaped conductors include a grounded ground conductor (604) that extends in the direction of extension along the high-potential conductor, low-potential conductor, and output conductor, The power conversion device according to feature B9, wherein the grounding conductor is provided at at least one of the outermost positions of a pair of plate-shaped conductors.

[0373] [Feature B11] Multiple high-potential conductors, low-potential conductors, and output conductors are provided. The upper switch component is connected to each of the multiple high-potential conductors and also to each of the multiple output conductors. The lower switch component is connected to each of the multiple output conductors and also to each of the multiple low-potential conductors. A power converter according to any one of features B1 to B10, wherein a capacitor component is connected to each of a plurality of high-potential conductors and also to each of a plurality of low-potential conductors.

[0374] [Feature B12] It comprises an upper and lower arm circuit (83) that is electrically connected between a high-potential conductor and a low-potential conductor, The upper switch component has an upper arm switch (86A) included in the upper arm (84) of the upper arm circuit, The power converter according to any one of features B1 to B11, wherein the lower switch component has a lower arm switch (86B) included in the lower arm (85) of the upper and lower arm circuit.

[0375] [Feature B13] A power converter (80) that converts electricity, A high-potential conductor (601) extends in the direction of extension (CD) and is supplied with power on the high-potential side, A low-potential conductor (602) extends in the direction of extension along the high-potential conductor and is supplied with power on the low-potential side, An output conductor (603) extends in the direction of extension along the high-potential conductor and the low-potential conductor, and outputs power, An upper switch component (530A) has an upper input terminal (532A) connected to a high-potential conductor and an upper output terminal (533A) connected to an output conductor, and switches to convert power. A lower switch component (530B) has a lower input terminal (532B) connected to an output conductor and a lower output terminal (533B) connected to a low-potential conductor, and switches to convert power. Capacitor components (580, 580A, 580B) have a high-capacitor terminal (582) connected to a high-potential conductor and a low-capacitor terminal (583) connected to a low-potential conductor, and are electrically connected in parallel to the upper switch component and the lower switch component. Equipped with, The output conductor has an upper output terminal and a lower input terminal connected at positions spaced apart from each other in the direction of extension. The high-potential conductor is connected such that at least one of the upper input terminal and the high-capacitor terminal is located between the upper output terminal and the lower input terminal, and the upper input terminal and the high-capacitor terminal are spaced apart in the extrinsic direction. A power converter is provided in which a low-potential conductor is positioned such that at least one of the lower output terminal and the low-capacitor terminal is located between the upper output terminal and the lower input terminal, and the lower output terminal and the low-capacitor terminal are spaced apart in the extrinsic direction.

[0376] [Feature B14] A power converter (80) that converts electricity, Power conductors (601, 602) that extend in the direction of extension (CD) and to which power is supplied, An output conductor (603) extends in the direction of extension along the power conductor and outputs power, The upper switch component (530A) on the high-potential side, which switches to convert power, The lower switch component (530B) on the low-potential side switches to convert power, Parallel components (580, 580A, 580B) electrically connected in parallel to the upper and lower switch components, Equipped with, The output conductor is connected such that the output current (IoA, IoB) flows through the output conductor in the direction extending from the upper switch component to the lower switch component, with the upper and lower switch components spaced apart from each other in the direction extending. A power converter in which a power conductor is connected such that, in an overlapping region (AO) that overlaps with the output current in the direction of extension, a parallel current (IpA, IpB, InA, InB) flows through the power conductor between the parallel component and one of the upper switch component and one of the lower switch component in the opposite direction to the output current.

[0377] [Feature C1] A power converter (80) that converts electricity, Case (90) having an outer peripheral wall (91) that extends in a ring shape, It has power terminals (532, 533) to which power is supplied, control terminals (534, 535) for controlling the conversion of power, and a switch body (531) that supports the power terminals and the control terminals, and a switch component (530) that switches to convert power, A power connection target (510) has a power outer end (512) that extends in the circumferential direction (CD) of the outer outer wall along the inner surface (90b) of the outer outer wall and is connected to the power terminal so as to be energized, A control connection target (550) having a control outer end (552) extending circumferentially along the inner circumferential surface and to which a control terminal is connected in a way that allows power to pass through, Equipped with, The power converter consists of multiple switch components arranged circumferentially along the outer edges of the power and control circuits.

[0378] [Feature C2] The power conversion device described in feature C1, wherein the switch body is located closer to the power connection target than to the control connection target.

[0379] [Feature C3] The control terminal has a control connection section (534ex, 535ex) that connects the switch body and the device to be controlled. The power terminal is shorter than the control connection section, and the power conversion device has a power connection section (532ex, 533ex) that connects the switch body and the power connection target, as described in feature C1 or C2.

[0380] [Feature C4] The power terminal is folded in a shape that extends away from the power connection target in the axial direction (AD) of the outer wall and also extends towards the power connection target, as described in any one of features C1 to C3 of the power conversion device.

[0381] [Feature C5] The power connection target is a power substrate (510) extending in a direction perpendicular to the axial direction (AD) of the outer wall. The target of the control connection is a target substrate (550) extending in a direction perpendicular to the axial direction. The power board and the target board are arranged in the axial direction, and the power conversion device is described in one of the features C1 to C4.

[0382] [Feature C6] The power conversion device according to feature C5, wherein the power terminals are located at a position separated from the power board side, from the midpoint between the power board and the target board in the axial direction.

[0383] [Feature C7] The power board has power busbars (601, 602, 603) that extend along the control outer edge, which is the outer edge of the power board. The power terminal is connected to the power busbar, thereby enabling power to be supplied to the power board, as described in feature C5 or C6 of the power conversion device.

[0384] [Feature C8] The power outer end and the control outer end extend in an annular shape in the circumferential direction. A power conversion device according to any one of features C1 to C7, wherein the switch array (530R) of multiple switch components arranged in the circumferential direction extends in a ring shape in the circumferential direction.

[0385] [Feature C9] A power conversion device described in any one of features C1 to C8, with the switch body located on the inner circumference.

[0386] [Feature C10] The switch body has a pair of panel surfaces: an inner panel surface (531a) facing inward in the radial direction (RD) of the outer peripheral wall, and an outer panel surface (531b) facing outward in the radial direction. A power conversion device as described in Feature C9, wherein heat dissipation from the outer panel surface is greater than heat dissipation from the inner panel surface.

[0387] [Feature D1] A power converter (80) that converts electricity, Case (90) having an outer peripheral wall (91) that extends in a ring shape, Multiple heat-generating components (530) are arranged in the circumferential direction (CD) of the outer wall, are in contact with the inner circumferential surface (90b) of the outer wall, and generate heat when an electric current is applied. Equipped with, The outer surface (90a) of the outer wall is a heat dissipation surface that releases heat transferred from the heat-generating components to the inner surface to the outside of the power conversion device.

[0388] [Feature D2] The power conversion device according to feature D1, comprising small heat-generating components (524, 580) provided in the radial direction (RD) of the outer peripheral wall, inside the heat-generating component (530), arranged in multiples in the circumferential direction, and generating less heat when energized than the heat-generating component.

[0389] [Feature D3] The heat-generating component array (530R), consisting of multiple heat-generating components arranged in the circumferential direction, extends in a ring shape in the circumferential direction. The power conversion device according to feature D2, wherein the array of small heat-generating components (524R, 580R), which consists of multiple small heat-generating components arranged in the circumferential direction, extends in a ring shape in the circumferential direction radially inward from the array of heat-generating components.

[0390] [Feature D4] As small heat-generating components, there are multiple first small heat-generating components (580) arranged in the circumferential direction, As small heat-generating components, there are second small heat-generating components (524) which are provided radially inward from the first small heat-generating component, arranged in multiples circumferentially, and which generate less heat when energized than the first small heat-generating component, A power conversion device as described in D2 or D3, which is equipped with the feature D2 or D3.

[0391] [Feature D5] The first component row (580R), consisting of multiple first small heat components arranged in the circumferential direction, extends in a ring shape in the circumferential direction. The power conversion device according to feature D4, wherein a second component row (524R) consisting of multiple second small thermal components arranged circumferentially extends in an annular shape circumferentially, radially inward from the first component row.

[0392] [Feature D6] It comprises a plate member (510) provided at a position spaced radially inward from the inner circumferential surface, and extending in a plate-like manner in a direction perpendicular to the axial direction (AD) of the outer circumferential wall, A power conversion device according to any one of features D2 to D5, wherein multiple small heating components are fixed to a plate member.

[0393] [Feature D7] It has multiple heat-generating components arranged in the circumferential direction, and multiple heat-generating groups (530G) arranged in the circumferential direction, As small heat-generating components, there are group-aligned components (580c) positioned radially within the heat-generating group, A power converter having one of the features described in D2 to D6.

[0394] [Feature D8] A dense region (Asw1) is provided in which multiple heat-generating components are arranged in a circumferential direction and are densely packed together, There are no heat-generating components, multiple units are arranged in the circumferential direction, and an intermediate region (Asw2) is provided between two adjacent densely packed regions in the circumferential direction. An external connector (96) is provided in the intermediate region of the outer wall for connecting a heat-generating component to an external device (31) in a way that allows power to be supplied, As small heat-generating components, connector alignment components (524b) are provided in positions that are radially aligned with the external connector, A power conversion device having one of the features described in D2 to D7.

[0395] [Feature D9] The power conversion device according to any one of features D1 to D8, wherein the heat-generating component has a plate-shaped component body (531) and component terminals (532 to 535) extending from the component body, and the outer surface (531b) of the component body is in contact with the outer peripheral wall while overlapping the inner peripheral surface.

[0396] [Feature D10] The power conversion device described in Feature D9, wherein the heat dissipation from the outer surface of the component body is greater than the heat dissipation from the inner surface (531a) facing the opposite side of the outer surface.

[0397] [Feature D11] A connection board (510, 550) to which component terminals are connected, A substrate support part (500) fixed to the outer periphery wall and supporting the connecting substrate, Equipped with, In the case of a heat-generating component, the heat from the component body is released to the outside from the outer surface via the outer wall, and the heat from the component terminals is released to the outside from the outer surface via the connecting substrate, substrate support portion and outer wall, as described in the power conversion device according to feature D9 or D10. [Explanation of symbols]

[0398] <Composition group A> 50...EPU as a rotating electric machine unit, 60...Motor device as a rotating electric machine, 62...End plate as a cover, 71...Motor outer wall as an electric machine outer wall, 80...Inverter device as a power conversion device, 86...Arm switch as a conversion switch, 90...Inverter housing as a case, 90b...Inner surface, 91...Inverter outer wall as an outer wall and device outer wall, 92...Inverter fin as a heat dissipation fin, 146...Motor current sensor as a mounted component, 147...Battery current sensor as a mounted component, 200...Stator as a stator, 300...Rotor as a rotor, 501...Beam section, 502...Beam connecting section, 510...High-voltage substrate as a plate member and first plate member, 512... Outer edge, 525... Common mode coil section as a mounted component, 526... Normal mode coil section as a mounted component, 527... Y capacitor section as a mounted component, 528... X capacitor section as a mounted component, 530... Arm switch section as a switch component, 531... Switch body, 532... Source terminal as a switch terminal, 533... Drain terminal as a switch terminal, 534... Gate terminal as a switch terminal, 535... Driver source terminal as a switch terminal, 539... Switch group, 545... Heat insulation section, 550... Plate member, second plate member and drive board as low-voltage substrate, 552... Outer edge, 580... Smoothing capacitor section as a mounted component, AD... Axial direction, CD... Circumferential direction, RD... Radial direction.

[0399] <Composition group B> 80...Inverter device as a power conversion device, 83...Upper and lower arm circuit, 84...Upper arm, 85...Lower arm, 86A...Upper arm switch, 86B...Lower arm switch, 530A...Upper arm switch section as an upper switch component, 530Af...Farthest upper component, 530B...Lower arm switch section as a lower switch component, 530Bf...Farthest lower component, 530GA...Upper switch group, 530GB...Lower switch group, 532A...Upper drain terminal as an upper input terminal, 532B...Lower input terminal 533A…Upper drain terminal as upper output terminal, 533B…Lower source terminal as lower output terminal, 533…Drain terminal as terminal, 534…Gate terminal as input control terminal, 535…Driver source terminal as output control terminal, 580…Smoothing capacitor section as capacitor component and parallel component, 580A…Upper capacitor section as capacitor component, upper capacitor component, first capacitor component and parallel component, 580B…Lower capacitor section as capacitor component, lower capacitor component, second capacitor component and parallel component, 580GA…Upper capacitor group as first capacitor group, 580GB…Lower capacitor group as second capacitor group, 582…P capacitor terminal as high capacitor terminal, 583…N capacitor terminal as low capacitor terminal, 601…P busbar as high potential conductor, plate conductor, first plate section and power conductor, 602…N busbar as low potential conductor, plate conductor, second plate section and power conductor, 603… Output busbar as output conductor and plate conductor, 604... Earth busbar as plate conductor and ground conductor, AO... Overlapping region, IoA... Upper output current as output current, IoB... Lower output current as output current, IpA... Upper P current as high potential current and parallel current, IpB... Lower P current as high potential current and parallel current, InA... Upper N current as low potential current and parallel current, InB... Lower N current as low potential current and parallel current, CD... Circumferential direction as extension direction, RD... Radial direction as orthogonal direction.

[0400] <Composition group C> 60...Motor device as a rotating electric machine, 80...Inverter device as a power conversion device, 90...Inverter housing as a case, 90b...Inner circumferential surface, 91...Inverter outer circumferential wall as an outer circumferential wall, 510...High voltage board as a power connection target and power board, 512...Outer circumferential end as a power outer circumferential end, 530...Arm switch section as a switch component, 530R...Arm switch row as a switch row, 531...Switch body, 531a...First board surface as an inner board surface, 531b...Second board surface as an outer board surface, 532...Source terminal as a power terminal, 532ex...Sowary as a power connection section - Exposed part, 533... Drain terminal as a power terminal, 533ex... Exposed drain part as a power connection part, 534... Gate terminal as a control terminal, 534ex... Exposed gate part as a control connection part, 535... Driver source terminal as a control terminal, 535ex... Exposed driver source part as a control connection part, 550... Drive board as the control connection target and target board, 552... Outer edge as the control outer edge, 601... P busbar as a power busbar, 602... N busbar as a power busbar, 603... Output busbar as a power busbar, AD... Axial direction, CD... Circumferential direction, RD... Radial direction.

[0401] <Configuration group D> 31...Battery as an external device, 80...Inverter device as a power conversion device, 90...Inverter housing as a case, 90a...Outer peripheral surface as a heat dissipation surface, 90b...Inner peripheral surface, 91...Inverter outer peripheral wall as an outer peripheral wall, 96...Inverter connector as an external connector, 500...Component support part as a board support part, 510...High-voltage board as a plate member and connecting board, 524...Filter part as a small heat component and a second small heat component, 524b...Connector arrangement part, 524R...Filter arrangement as a small heat component row and a second component row, 530...Arm switch part as a heat generating component, 530G...Switch group as a heat generating group ,530R...Arm switch row as a heat-generating component row, 531...Switch body as a component body, 531b...Second board surface as a board surface, 532...Source terminal as a component terminal, 533...Drain terminal as a component terminal, 534...Gate terminal as a component terminal, 535...Driver source terminal as a component terminal, 550...Driver board as a connection board, 580...Smoothing capacitor section as a small heat-generating component and first small heat-generating component, 580c...Group of components, 580R...Smoothing capacitor row as a small heat-generating component row and first component row, Asw1...Switch region as a densely packed region, Asw2...Intermediate region, AD...Axial direction, CD...Circumferential direction, RD...Radial direction.

Claims

1. A power conversion device (80) that converts electricity, Case (90) having an outer wall (91) that extends in a ring shape, Multiple heat-generating components (530) are arranged in the circumferential direction (CD) of the outer peripheral wall, are in contact with the inner circumferential surface (90b) of the outer peripheral wall, and generate heat when an electric current is applied. The aforementioned small heat-generating components (524, 580) are arranged in multiples in the circumferential direction and generate less heat when energized than the aforementioned heat-generating components, A dense region (Asw1) is provided in which a plurality of heat-generating components are arranged in the circumferential direction and are densely clustered together, The aforementioned heat-generating component is not provided, and there is an intermediate region (Asw2) provided between two adjacent densely packed regions in the circumferential direction, An external connector (96) is provided in the intermediate region of the outer peripheral wall for connecting the heat-generating component to an external device (31) in a way that allows power to be supplied. Equipped with, The outer surface (90a) of the outer wall is a heat dissipation surface that releases heat transferred from the heat-generating component to the inner surface to the outside, in a power conversion device.

2. The power conversion device according to claim 1, wherein the small heat component is provided inward of the heat-generating component (530) in the radial direction (RD) of the outer peripheral wall.

3. The power conversion device according to claim 1 or 2, further comprising, as the small heat component, a connector arrangement component (524b) provided on the external connector at a position aligned radially (RD) with respect to the outer peripheral wall.

4. The heat-generating component row (530R) consisting of the plurality of heat-generating components arranged in the circumferential direction extends in an annular shape in the circumferential direction. The power conversion device according to claim 1 or 2, wherein the array of small heat components (524R, 580R) arranged in the circumferential direction extends in an annular shape in the circumferential direction, on the inside of the radial direction (RD) of the outer peripheral wall, compared to the array of heat-generating components.

5. The aforementioned small heating components include a plurality of first small heating components (580) arranged in the circumferential direction, The aforementioned small heat-generating components include a second small heat-generating component (524) which is provided inward from the first small heat-generating component in the radial direction (RD) of the outer peripheral wall, is arranged in a plurality in the circumferential direction, and generates less heat when energized than the first small heat-generating component, The power conversion device according to claim 1 or 2, comprising:

6. The first component row (580R) consisting of the plurality of first small heating components arranged in the circumferential direction extends in an annular shape in the circumferential direction. The power conversion device according to claim 5, wherein the second component row (524R) of the plurality of second small heating components arranged in the circumferential direction extends in an annular manner in the circumferential direction, on the inside of the radial direction (RD) of the outer peripheral wall, compared to the first component row.

7. The system includes a plate member (510) provided at a position spaced inward from the inner circumferential surface in the radial direction (RD) of the outer circumferential wall, and extending in a plate-like manner in a direction perpendicular to the axial direction (AD) of the outer circumferential wall, The power conversion device according to claim 1 or 2, wherein the plurality of the small heating components are fixed to the plate member.

8. The heating elements are arranged in the circumferential direction, and the heating groups (530G) are arranged in the circumferential direction, The aforementioned small heat-generating components include a group of components (580c) provided in the heat-generating group at positions aligned radially (RD) along the outer peripheral wall, The power conversion device according to claim 1 or 2, comprising:

9. The power conversion device according to claim 1 or 2, wherein the heat-generating component has a plate-shaped component body (531) and component terminals (532 to 535) extending from the component body, and the outer surface (531b) of the component body is in contact with the outer peripheral wall while overlapping the inner peripheral surface.

10. The connection boards (510, 550) to which the aforementioned component terminals are connected, A substrate support portion (500) fixed to the outer peripheral wall and supporting the connecting substrate, Equipped with, The power conversion device according to claim 9, wherein, in the heat-generating component, heat from the component body is released to the outside from the outer surface via the outer peripheral wall, and heat from the component terminals is released to the outside from the outer surface via the connecting substrate, the substrate support portion, and the outer peripheral wall.

11. A power conversion device (80) that converts electricity, Case (90) having an outer wall (91) that extends in a ring shape, Multiple heat-generating components (530) are arranged in the circumferential direction (CD) of the outer peripheral wall, are in contact with the inner circumferential surface (90b) of the outer peripheral wall, and generate heat when an electric current is applied. Equipped with, The outer peripheral surface (90a) of the outer peripheral wall is a heat dissipation surface that releases heat transferred from the heat-generating component to the inner peripheral surface to the outside. The heat-generating component has a plate-shaped component body (531) and component terminals (532 to 535) extending from the component body, and the outer surface (531b) of the component body is in contact with the outer peripheral wall while overlapping the inner peripheral surface. moreover, The connection boards (510, 550) to which the aforementioned component terminals are connected, A substrate support portion (500) fixed to the outer peripheral wall and supporting the connecting substrate, A power converter equipped with the following features.

12. The power conversion device according to claim 11, wherein, in the heat-generating component, the heat of the component body is released to the outside from the outer surface via the outer peripheral wall, and the heat of the component terminals is released to the outside from the outer surface via the connecting substrate, the substrate support portion and the outer peripheral wall.

13. The power conversion device according to claim 11 or 12, wherein the heat dissipation from the outer surface of the component body is greater than the heat dissipation from the inner surface (531a) facing the opposite side of the outer surface.

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