Power conversion device
Patent Information
- Application Number
- JP2024230469
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-03-14
- Estimated Expiration
- 2041-05-12
Smart Images
Figure 2025036642000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a power conversion device. [Background technology]
[0002] Conventionally, a power conversion device including an inverter and a rotating electric machine having a winding electrically connected to the inverter is known. In order to drive the rotating electric machine, switching control is performed on the upper and lower arm switches that constitute the inverter. This switching control generates noise.
[0003] Patent Document 1 describes a power conversion device in which an inverter case that houses an inverter is disposed above a motor case that houses a rotating electric machine, and the inverter case and the motor case are connected by a pair of vibration-isolating members. The vibration-isolating members are configured so that the impedance of the path between the motor case, the vibration-isolating member, and the inverter case is smaller than the impedance of the path between the motor case and the body ground. This allows noise propagating from the inverter side to the rotating electric machine side to be returned to the inverter case side via the motor case and the vibration-isolating member, thereby reducing noise flowing to the body ground. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] JP 2015-2610 A Summary of the Invention [Problem to be solved by the invention]
[0005] Some power conversion devices include upper and lower arm switches connected in parallel to a series connection of a first power storage unit and a second power storage unit, and a neutral point wiring that electrically connects the negative electrode side of the first power storage unit and the positive electrode side of the second power storage unit to a neutral point of the winding. In this power conversion device, switching control of the upper and lower arm switches is performed so that a current flows between the first power storage unit and the second power storage unit via the inverter, the winding, and the neutral point wiring. This switching control also generates noise.
[0006] The present invention has a main object to provide a power conversion device that has neutral wiring electrically connecting the negative electrode side of a first storage unit and the positive electrode side of a second storage unit to a neutral point of a winding, and that can reduce noise leaking out from the power conversion device to the outside. [Means for solving the problem]
[0007] The present invention provides an inverter including a series-connected body of upper and lower arm switches, the series-connected body being connected in parallel to a series-connected body of a first power storage unit and a second power storage unit; a rotating electric machine having a winding electrically connected to the inverter; a neutral point wiring electrically connecting a negative electrode side of the first power storage unit and a positive electrode side of the second power storage unit to a neutral point of the winding; a control unit that performs switching control of the upper and lower arm switches so that a current flows between the first power storage unit and the second power storage unit via the inverter, the winding, and the neutral point wiring; a case that houses at least the inverter and has a shielding function; At least a portion of the neutral wiring is housed within the case.
[0008] In the present invention, the case that houses at least a portion of the neutral point wiring has a shielding function, so that it is possible to reduce noise radiated to the outside of the power conversion device via the neutral point wiring. [Brief description of the drawings]
[0009] [Figure 1] 1 is a configuration diagram of a power conversion device according to a first embodiment. [Diagram 2] FIG. 11 is a configuration diagram of a power conversion device according to a second embodiment. [Diagram 3] FIG. 11 is a configuration diagram of a power conversion device according to a third embodiment. [Figure 4] FIG. 13 is a configuration diagram of a power conversion device according to a fourth embodiment. [Diagram 5] FIG. 13 is a configuration diagram of a power conversion device according to a fifth embodiment. [Figure 6] FIG. 13 is a configuration diagram of a power conversion device according to a sixth embodiment. [Figure 7] FIG. 13 is a configuration diagram of a power conversion device according to a seventh embodiment. [Figure 8] FIG. 13 is a configuration diagram of a power conversion device according to another embodiment. [Figure 9] FIG. 13 is a configuration diagram of a power conversion device according to another embodiment. [Figure 10] FIG. 13 is a configuration diagram of a power conversion device according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] Hereinafter, embodiments of the power conversion device according to the present invention will be described with reference to the drawings. The power conversion device is mounted on a vehicle such as an electric vehicle or a hybrid vehicle. In each embodiment, the same or corresponding components are denoted by the same reference numerals for convenience.
[0011] First Embodiment As shown in Fig. 1, the power conversion device 10 includes a battery pack 20, an inverter 30, and a rotating electric machine 40. The rotating electric machine 40 is a three-phase synchronous machine, and includes U-, V-, and W-phase windings 41U, 41V, and 41W that are star-connected as stator windings. The phase windings 41U, 41V, and 41W are arranged with an electrical angle of 120° between them. The rotating electric machine 40 is, for example, a permanent magnet synchronous machine. In this embodiment, the rotating electric machine 40 is an in-vehicle main engine, and serves as a power source for running the vehicle.
[0012] The inverter 30 includes three phases of series-connected upper arm switches QUH, QVH, and QWH and lower arm switches QUL, QVL, and QWL. In this embodiment, a voltage-controlled semiconductor switching element, specifically an IGBT, is used as each switch QUH, QVH, QWH, QUL, QVL, and QWL. Therefore, the high-potential terminal of each switch QUH, QVH, QWH, QUL, QVL, and QWL is a collector, and the low-potential terminal is an emitter. Diodes DUH, DVH, DWH, DUL, DVL, and DWL are connected in inverse parallel to each switch QUH, QVH, QWH, QUL, QVL, and QWL as freewheel diodes.
[0013] A first end of the U-phase winding 41U is connected to the emitter of the U-phase upper arm switch QUH and the collector of the U-phase lower arm switch QUL via the U-phase wiring 32U. A first end of the V-phase winding 41V is connected to the emitter of the V-phase upper arm switch QVH and the collector of the V-phase lower arm switch QVL via the V-phase wiring 32V. A first end of the W-phase winding 41W is connected to the emitter of the W-phase upper arm switch QWH and the collector of the W-phase lower arm switch QWL via the W-phase wiring 32W. Second ends of the U-, V-, and W-phase windings 41U, 41V, and 41W are connected to each other at the neutral point O. In this embodiment, the number of turns of each phase winding 41U, 41V, and 41W is set to be the same. As a result, for example, the inductance of each phase winding 41U, 41V, and 41W is set to be the same. In this embodiment, the U-, V-, and W-phase wirings 32U, 32V, and 32W correspond to the "power wirings."
[0014] The inverter 30 includes a capacitor 31 that connects the collectors of the upper arm switches QUH, QVH, and QWH to the emitters of the lower arm switches QUL, QVL, and QWL. The capacitor 31 may be provided outside the inverter 30.
[0015] The power conversion device 10 includes a common case 110 that houses the inverter 30 and the rotating electric machine 40. In other words, the power conversion device 10 is a so-called mechanically and electrically integrated device. The common case 110 includes, for example, a bottom plate portion, a peripheral wall portion provided on the periphery of the bottom plate portion, and a top plate portion that covers the side of the peripheral wall portion opposite to the bottom plate portion. In the housing space surrounded by the bottom plate portion, the peripheral wall portion, and the top plate portion, the inverter 30 and the rotating electric machine 40 are disposed on the bottom plate portion. In this embodiment, the common case 110 is made of aluminum and has an electromagnetic shielding function.
[0016] In the common case 110, the collectors of each of the upper arm switches QUH-QWH are connected to a high potential side inverter terminal TIH of the common case 110 by a high potential side power wiring 33H. Also, in the common case 110, the emitters of each of the lower arm switches QUL, QVL, QWL are connected to a low potential side inverter terminal TIL of the common case 110 by a low potential side power wiring 33L.
[0017] The power conversion device 10 includes a battery case 100 that houses a battery pack 20. The battery case 100 has, for example, a bottom plate portion, a peripheral wall portion provided on the peripheral edge portion of the bottom plate portion, and a top plate portion that covers the side of the peripheral wall portion opposite to the bottom plate portion. In a housing space surrounded by the bottom plate portion, the peripheral wall portion, and the top plate portion, the battery pack 20 is disposed on the bottom plate portion. In this embodiment, the battery case 100 is made of aluminum and has an electromagnetic shielding function. The battery case 100 is disposed at a position separated from the common case 110.
[0018] The battery case 100 and the common case 110 are disposed in the body of the vehicle, which functions as the body ground BG. For example, the battery case 100 and the common case 110 are disposed in the body, respectively, or the battery case 100 and the common case 110 are disposed in a stacked state in the body.
[0019] The power conversion device 10 includes a high potential side wiring 80H, a low potential side wiring 80L, and a battery side inter-case wiring 80M. The high potential side wiring 80H connects a high potential side inverter terminal TIH of the common case 110 and a high potential side battery terminal TBH of the battery case 100. The low potential side wiring 80L connects a low potential side inverter terminal TIL of the common case 110 and a low potential side battery terminal TBL of the battery case 100. In other words, the high potential side wiring 80H and the low potential side wiring 80L are disposed outside the battery case 100 and the common case 110, respectively. Each of the terminals TIH, TBH, TIL, and TBL is, for example, a connector.
[0020] The battery pack 20 is configured as a series connection of battery cells, which are single batteries. The terminal voltages (e.g., rated voltages) of the battery cells constituting the battery pack 20 are set to be the same, for example. The battery cells may be, for example, secondary batteries such as lithium ion batteries.
[0021] In this embodiment, among the battery cells constituting the battery pack 20, a series connection of multiple battery cells on the high potential side constitutes a first storage battery 21 (corresponding to the "first power storage section"), and a series connection of multiple battery cells on the low potential side constitutes a second storage battery 22 (corresponding to the "second power storage section"). In other words, the battery pack 20 is divided into two blocks.
[0022] In the battery pack 20, an intermediate terminal B is connected to the negative terminal of the first storage battery 21 and the positive terminal of the second storage battery 22.
[0023] The battery case 100 houses a monitoring unit 50. The monitoring unit 50 monitors the terminal voltage, SOC, SOH, temperature, etc. of each battery cell that constitutes the battery pack 20. Monitoring information from the monitoring unit 50 is input to a control device 70 (corresponding to a "control unit") provided in the power conversion device 10. In this embodiment, the control device 70 is housed in a common case 110.
[0024] The power conversion device 10 includes a connection path 60 and a neutral point switch 61. The connection path 60 and the neutral point switch 61 are housed in a common case 110. The connection path 60 connects a neutral point O and a neutral point inverter terminal TIM of the common case 110. The neutral point switch 61 is provided on the connection path 60. In this embodiment, a relay is used as the neutral point switch 61. When the neutral point switch 61 is turned on, the neutral point inverter terminal TIM and the neutral point O are electrically connected. On the other hand, when the neutral point switch 61 is turned off, the neutral point inverter terminal TIM and the neutral point O are electrically disconnected.
[0025] The neutral point inverter terminal TIM is connected to the neutral point battery terminal TBM of the battery case 100 via the battery side case wiring 80M. In other words, the battery side case wiring 80M is disposed outside each of the battery case 100 and the common case 110. Each of the terminals TIM, TBM is, for example, a connector. In this embodiment, the connection path 60 and the battery side case wiring 80M correspond to the "neutral point wiring."
[0026] The power conversion device 10 includes a current sensor 62. The current sensor 62 detects a current flowing through the connection path 60. A detection value of the current sensor 62 is input to the control device 70. The current sensor 62 is accommodated in the common case 110.
[0027] The control device 70 is mainly composed of a microcomputer, which is equipped with a CPU. The functions provided by the microcomputer can be provided by software recorded in a physical memory device and a computer that executes the software, by software alone, by hardware alone, or by a combination of these.
[0028] The control device 70 performs switching control of the switches QUH to QWL constituting the inverter 30 so as to feedback control the control amount of the rotating electric machine 40 to its command value. The control amount is, for example, torque. In each phase, the upper arm switch and the lower arm switch are alternately turned on. The control device 70 turns on or off the neutral point switch 61, and is capable of communicating with the monitoring unit 50.
[0029] The control device 70 performs temperature rise control and voltage equalization control with the neutral point switch 61 turned on. The temperature rise control is switching control of the inverter 30 for passing AC current between the first storage battery 21 and the second storage battery 22 via the connection path 60 and the battery-side case wiring 80M. This control raises the temperature of the battery pack 20. The voltage equalization control is switching control of the inverter 30 for passing DC current from one of the first storage battery 21 and the second storage battery 22 to the other via the connection path 60 and the battery-side case wiring 80M. This control supplies energy from one of the first storage battery 21 and the second storage battery 22 to the other, and equalizes the voltages of the first storage battery 21 and the second storage battery 22.
[0030] The control device 70 calculates a neutral point command current for temperature rise control or voltage equalization control. The control device 70 controls the current detected by the current sensor 62 to the neutral point command current. The control device 70 can also perform temperature rise control and voltage equalization control simultaneously. Furthermore, when the control device 70 does not perform temperature rise control or voltage equalization control but controls the control amount of the rotating electric machine 40, it turns off the neutral point switch 61.
[0031] The power conversion device 10 includes a battery-side shielded wire 90. The battery-side shielded wire 90 collectively covers the high-potential side wiring 80H, the low-potential side wiring 80L, and the battery-side inter-case wiring 80M. When the rotating electric machine 40 is driven or when temperature rise control or voltage equalization control is performed, switching control of the inverter 30 causes current to flow through the wirings 80H, 80L, and 80M, generating noise. The battery-side shielded wire 90 can reduce noise radiated to the outside via the wirings 80H, 80L, and 80M.
[0032] The high potential side wiring 80H, the low potential side wiring 80L, and the battery side inter-case wiring 80M are bundled together by the battery side shield wire 90. This prevents the wiring 80H, 80L, and 80M, which are noise radiation sources, from spreading out, and enhances the noise reduction effect of the battery side shield wire 90.
[0033] The connection path 60 is housed within the common case 110. The common case 110 functions as an electromagnetic shield, so that noise radiated to the outside of the common case 110 via the connection path 60 can be reduced.
[0034] The battery-side shielded wire 90 electrically connects the battery case 100 and the common case 110. This reduces noise that leaks to the body ground BG. The principle by which the leaking noise can be reduced will be described below.
[0035] 1, CI indicates the stray capacitance formed between the inverter 30 and the common case 110 (hereinafter, inverter stray capacitance), CM indicates the stray capacitance formed between the rotating electric machine 40 and the common case 110 (hereinafter, motor stray capacitance), and CB indicates the stray capacitance formed between the battery pack 20 and the battery case 100 (hereinafter, battery stray capacitance).
[0036] Noise (common mode noise) generated by switching control of the inverter 30 propagates from the inverter 30 to the common case 110 via the inverter stray capacitance CI. Here, the common case 110 and the battery case 100 are electrically connected by the battery side shield wire 90. Therefore, the impedance between the common case 110 and the battery case 100 is lower than the impedance between the common case 110 and the body ground BG and between the common case 110 and the battery case 100 and between the body ground BG and between the battery case 100 and the battery side shield wire 90. As a result, most of the noise propagated to the common case 110 flows back to the common case 110 via the battery case 100 and the battery side shield wire 90. This makes it possible to suitably reduce noise flowing to the body ground BG.
[0037] <Modification of the first embodiment> The battery case 100 and the common case 110 may be formed of a non-metallic material (e.g., synthetic resin) that does not have an electromagnetic shielding function, rather than a metallic material. In this case, the surface of each case 100, 110 may be subjected to a plating process (metal plating process) that has an electromagnetic shielding function. In this case, the plated portions of each case 100, 110 may be electrically connected to each other by the battery-side shield wire 90.
[0038] When the common case 110 is made of a non-metallic material that does not have an electromagnetic shielding function, the U-, V-, and W-phase wirings 32U, 32V, and 32W and the connection path 60 may be collectively covered by a shield wire within the common case 110. This makes it possible to reduce noise radiation to the outside of the common case 110.
[0039] A wall portion may be provided inside the common case 110 to separate the accommodation space for the inverter 30 from the accommodation space for the rotating electric machine 40. In this case, the U-, V-, and W-phase wirings 32U, 32V, and 32W may be inserted into through holes formed in the wall portion.
[0040] <Second embodiment> Hereinafter, the second embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, as shown in FIG. 2, the inverter 30 and the rotating electric machine 40 are housed in separate cases.
[0041] The inverter 30 is housed in an inverter case 120 (corresponding to a "first case"), and the rotating electric machine 40 is housed in a motor case 130 (corresponding to a "second case"). The inverter case 120, the motor case 130, and the battery case 100 are disposed at positions spaced apart from each other.
[0042] The inverter case 120 and the motor case 130 each have, for example, a bottom plate, a peripheral wall provided on the periphery of the bottom plate, and a top plate covering the side of the peripheral wall opposite to the bottom plate. The inverter 30 is disposed on the bottom plate of the inverter case 120, and the rotating electric machine 40 is disposed on the bottom plate of the motor case 130. In this embodiment, the inverter case 120 and the motor case 130 are made of aluminum and have an electromagnetic shielding function. In this embodiment, the inverter case 120 has a high-potential inverter terminal TIH, a neutral inverter terminal TIM, and a low-potential inverter terminal TIL.
[0043] The emitter of the U-phase upper arm switch QUH and the collector of the U-phase lower arm switch QUL are connected to a U-phase inverter terminal TU of the inverter case 120. The emitter of the V-phase upper arm switch QVH and the collector of the V-phase lower arm switch QVL are connected to a V-phase inverter terminal TV of the inverter case 120. The emitter of the W-phase upper arm switch QWH and the collector of the W-phase lower arm switch QWL are connected to a W-phase inverter terminal TW of the inverter case 120.
[0044] The power conversion device 10 includes U-, V-, and W-phase wirings 81U, 81V, and 81W. The phase wirings 81U to 81W are provided outside the inverter case 120 and the motor case 130, respectively.
[0045] The U-phase inverter terminal TU is connected to a motor U-phase terminal TMU of the motor case 130 via a U-phase wiring 81U. A first end of the U-phase winding 41U is connected to the motor U-phase terminal TMU. The V-phase inverter terminal TV is connected to a motor V-phase terminal TMV of the motor case 130 via a V-phase wiring 81V. A first end of the V-phase winding 41V is connected to the motor V-phase terminal TMV. The W-phase inverter terminal TW is connected to a motor W-phase terminal TMW of the motor case 130 via a W-phase wiring 81W. A first end of the W-phase winding 41W is connected to the motor W-phase terminal TMW.
[0046] The motor case 130 houses a motor side neutral point wiring 60M that connects the neutral point O and a motor neutral point terminal TMM of the motor case 130. The motor neutral point terminal TMM and the neutral point connection terminal TM of the inverter case 120 are connected by a motor side inter-case wiring 81M. Each of the terminals TM, TMM, TU, TV, TW, TMU, TMV, and TMW is, for example, a connector.
[0047] The inverter case 120 accommodates an inverter-side neutral point wiring 60I that connects the neutral point connection terminal TM and the neutral point inverter terminal TIM, a neutral point switch 61, and a current sensor 62. The neutral point switch 61 is provided on the inverter-side neutral point wiring 60I. The current sensor 62 of this embodiment detects a current flowing through the inverter-side neutral point wiring 60I. In this embodiment, the motor-side neutral point wiring 60M, the motor-side case-to-case wiring 81M, the inverter-side neutral point wiring 60I, and the battery-side case-to-case wiring 80M correspond to the "neutral point wiring."
[0048] The power conversion device 10 includes a motor-side shielded wire 91. The motor-side shielded wire 91 collectively covers the U- to W-phase wirings 81U-81W and the motor-side inter-case wiring 81M. This makes it possible to reduce noise radiated to the outside via the wirings 81U-81W, 81M due to switching control of the inverter 30.
[0049] The U-W phase wirings 81U-81W and the motor side inter-case wiring 81M are bundled together by the motor side shield wire 91. This prevents the wirings 81U-81W, 81M, which are noise emission sources, from spreading out, and enhances the noise reduction effect of the motor side shield wire 91.
[0050] The motor-side shielded wire 91 electrically connects the inverter case 120 and the motor case 130. This makes it possible to reduce noise that flows into the body ground BG.
[0051] 1, CI indicates an inverter stray capacitance formed between the inverter 30 and the inverter case 120, and CM indicates a motor stray capacitance formed between the rotating electric machine 40 and the motor case 130. The inverter case 120 and the motor case 130 are electrically connected by a motor-side shield wire 91. Therefore, the impedance between the inverter case 120 and the motor case 130 is lower than the impedance between the inverter case 120 and the body ground BG and between the motor case 130 and the body ground BG. As a result, similar to the first embodiment, noise flowing to the body ground BG can be reduced.
[0052] <Third embodiment> The third embodiment will be described below with reference to the drawings, focusing on the differences from the above-mentioned embodiments. In this embodiment, as shown in Fig. 3, an inverter 30, a rotating electric machine 40, and a battery pack 20 are accommodated in a common case 140. The case 140 also accommodates a monitoring unit 50, a control device 70, a current sensor 62, a connection path 60, and a neutral point switch 61.
[0053] The case 140 has, for example, a bottom plate, a peripheral wall provided on the periphery of the bottom plate, and a top plate covering the side of the peripheral wall opposite to the bottom plate. The inverter 30, the rotating electric machine 40, and the battery pack 20 are arranged on the bottom plate of the case 140. In this embodiment, the case 140 is made of aluminum and has an electromagnetic shielding function.
[0054] In FIG. 3, CI indicates the inverter stray capacitance formed between the inverter 30 and the case 140, CM indicates the motor stray capacitance formed between the rotating electric machine 40 and the case 140, and CB indicates the battery stray capacitance formed between the battery pack 20 and the case 140.
[0055] According to the present embodiment described above, the noise generated by the switching control of the inverter 30 can be effectively prevented from being radiated to the outside of the case 140.
[0056] <Modification of the third embodiment> Walls may be provided within the case 140 to separate the space for accommodating the rotating electric machine 40, the space for accommodating the inverter 30, and the space for accommodating the battery pack 20. In this case, it is sufficient that wiring is inserted into through holes in the walls that separate adjacent spaces among the respective spaces.
[0057] <Fourth embodiment> Hereinafter, the fourth embodiment will be described with reference to the drawings, focusing on the differences from the above-mentioned embodiments. In this embodiment, as shown in Fig. 4, the battery pack 20 and the inverter 30 are housed in a common case.
[0058] The battery pack 20 and the inverter 30 are housed in a common case 150. The common case 150 is disposed at a position separated from the motor case 130. The common case 150 has, for example, a bottom plate portion, a peripheral wall portion provided on the periphery of the bottom plate portion, and a top plate portion covering the side of the peripheral wall portion opposite to the bottom plate portion side. The battery pack 20 and the inverter 30 are disposed on the bottom plate portion of the common case 150. In this embodiment, the common case 150 is made of aluminum and has an electromagnetic shielding function. In this embodiment, the common case 150 has a U-phase inverter terminal TU, a V-phase inverter terminal TV, a W-phase inverter terminal TW, and a neutral point connection terminal TM.
[0059] In the common case 150, the neutral point connection terminal TM and the intermediate terminal B are connected by an inverter side neutral point wiring 60I. The common case 150 also accommodates the monitoring unit 50, the control device 70, the current sensor 62, the connection path 60, and the neutral point switch 61.
[0060] In FIG. 4, CI indicates an inverter stray capacitance formed between the inverter 30 and the common case 150, and CB indicates a battery stray capacitance formed between the battery pack 20 and the common case 150.
[0061] The motor-side shielded wire 91 electrically connects the common case 150 and the motor case 130. This makes it possible to reduce noise that flows into the body ground BG.
[0062] <Modification of the Fourth Embodiment> The common case 150 and the motor case 130 may be formed of a non-metallic material that does not have an electromagnetic shielding function, as in the modified example of the first embodiment, instead of a metallic material. In this case, the surfaces of the cases 130, 150 may be plated with a metal plating that has an electromagnetic shielding function. In this case, the plated portions of the cases 130, 150 may be electrically connected to each other by the motor-side shield wire 91.
[0063] When the common case 150 is made of a non-metallic material that does not have an electromagnetic shielding function, the high potential side power wiring 33H, the low potential side power wiring 33L, and the inverter side neutral point wiring 60I may be collectively covered with a shield wire within the common case 150. This makes it possible to reduce noise radiation to the outside of the common case 150.
[0064] A wall may be provided inside the common case 150 to separate the space for accommodating the inverter 30 from the space for accommodating the battery pack 20. In this case, the high-potential side power wiring 33H, the low-potential side power wiring 33L, and the inverter-side neutral point wiring 60I may be inserted into through holes formed in the wall.
[0065] <Fifth embodiment> The fifth embodiment will be described below with reference to the drawings, focusing on the differences from the above-mentioned embodiments. In this embodiment, as shown in Fig. 5, a first capacitor 32A and a second capacitor 32B are provided in a common case 110. The first capacitor 32A connects the high-potential side power wiring 33H and the connection path 60, and the second capacitor 32B connects the low-potential side power wiring 33L and the connection path 60.
[0066] According to the present embodiment described above, the noise (normal mode noise) flowing from the neutral point O to the battery pack 20 side through the connection path 60 is absorbed by the first capacitor 32A and the second capacitor 32B. This makes it possible to suitably reduce this noise.
[0067] Sixth Embodiment The sixth embodiment will be described below with reference to the drawings, focusing on differences from the above-mentioned embodiments. In this embodiment, as shown in FIG. 6, a common mode choke 33 is accommodated in a common case 110. The common mode choke 33 includes a first coil 34A provided on the high potential side power wiring 33H, a second coil 34B provided on the connection path 60, a third coil 34C provided on the low potential side power wiring 33L, and a common magnetic core (e.g., a ferrite core) around which the coils 34A, 34B, and 34C are wound. The magnetic core has, for example, a circular ring shape. The common mode choke 33 is configured so that when current flows from the rotating electric machine 40 side to the battery pack 20 side in each of the high potential side power wiring 33H, the connection path 60, and the low potential side power wiring 33L, the magnetic fluxes flowing through the magnetic cores do not cancel each other out.
[0068] According to the present embodiment described above, the coils 34A to 34C can be wound around a common core, which allows the common mode choke 33 to reduce common mode noise and the common mode choke 33 to be made smaller.
[0069] Seventh embodiment Hereinafter, the seventh embodiment will be described with reference to the drawings, focusing on the differences from the above-mentioned embodiments. In this embodiment, a part of the neutral wiring is arranged outside the common case 110, as shown in FIG.
[0070] In the common case 110, the neutral point inverter terminal TIM of the common case 110 and the neutral point O are connected by a connection path 60. The neutral point inverter terminal TIM and the neutral point battery terminal TBM of the battery case 100 are connected by a battery side inter-case wiring 80M. The neutral point switch 61 is provided on the battery side inter-case wiring 80M. In other words, the neutral point switch 61 is disposed outside the battery case 100 and the common case 110. In this embodiment, the connection path 60 and the battery side inter-case wiring 80M correspond to the "neutral point wiring". A part of the neutral point wiring is disposed outside the common case 110 in order to prevent the common case 110 from becoming large.
[0071] A bypass wiring 63, a first capacitor 32A, a second capacitor 32B, and a third capacitor 35 are provided inside the common case 110. A first end of the bypass wiring 63 is connected to a middle portion of the connection path 60. A second end of the bypass wiring 63 is connected to the high potential side power wiring 33H via the first capacitor 32A, and is connected to the low potential side power wiring 33L via the second capacitor 32B. This allows the first capacitor 32A and the second capacitor 32B to absorb noise that attempts to propagate from the neutral point O side to the battery pack 20 side via the connection path 60.
[0072] The bypass wiring 63 is provided with a third capacitor 35. This makes it possible to extract only high-frequency noise components that are about to propagate from the neutral point O side to the battery pack 20 side via the connection path 60 and send them to the first capacitor 32A and the second capacitor 32B. This makes it possible to prevent a direct current when voltage equalization control is performed and an alternating current when temperature rise control is performed from flowing through the bypass wiring 63.
[0073] Incidentally, the battery-side inter-case wiring 80M may be disposed in contact with the front side surface of the common case 110 in order to suppress radiation noise.
[0074] <Other embodiments> Each of the above embodiments may be modified as follows.
[0075] In the configuration shown in FIG. 7, the third capacitor 35 does not necessarily have to be provided.
[0076] The neutral point switch 61 may be provided on the peripheral wall of the inverter case 120 shown in Fig. 2 or on the peripheral wall of the common case 150 shown in Fig. 4. The following description will be given taking the common case 150 shown in Fig. 4 as an example.
[0077] 8, the common case 150 includes a bottom plate portion 151 and a peripheral wall portion 152 provided on the peripheral edge of the bottom plate portion 151. The motor case 130 includes a bottom plate portion 131 and a peripheral wall portion 132 provided on the peripheral edge of the bottom plate portion 131. A neutral point connection terminal TM is provided on the peripheral wall portion 152 of the common case 150, and a motor neutral point terminal TMM is provided on the peripheral wall portion 132 of the motor case 130. As a result, the neutral point wiring is drawn into the common case 150 via the neutral point connection terminal TM.
[0078] The neutral point switch 61 is provided near the neutral point connection terminal TM on the peripheral wall portion 152. The neutral point switch 61 is also provided on the neutral point wiring from the neutral point O to the intermediate terminal B, closer to the neutral point O than the central portion. The neutral point switch 61 is positioned in this manner for the reasons described below.
[0079] When temperature rise control and voltage equalization control are not performed and control of the control amount of the rotating electric machine 40 is performed, the neutral point switch 61 is turned off. In this case, the portion of the neutral point wiring from the neutral point O to the neutral point switch 61 functions as an antenna and may radiate noise. For this reason, it is desirable that the antenna portion be as short as possible. Therefore, by arranging the neutral point switch 61 as described above, the antenna portion is made as short as possible, thereby suppressing radiated noise.
[0080] The neutral point switch 61 is not limited to a relay. For example, a pair of N-channel MOSFETs with sources connected to each other or an IGBT may be used as the neutral point switch 61.
[0081] The neutral point switch 61 is not essential. In this case, the intermediate terminal B and the neutral point O are electrically connected at all times.
[0082] The rotating electric machine and the inverter may be of a type other than three phase, such as a five-phase or seven-phase type. Fig. 9 shows a power conversion device in the case of a five-phase type. In Fig. 9, X-phase upper and lower arm switches QXH, QXL and diodes DXH, DXL are added to the inverter 30, and Y-phase upper and lower arm switches QYH, QYL and diodes DYH, DYL are added. Furthermore, an X-phase winding 41X and a Y-phase winding 41Y are added to the rotating electric machine 40. Furthermore, an X-phase conductive member 32X and a Y-phase conductive member 32Y are added to the power conversion device 10.
[0083] The power conversion device 10 may be one shown in FIG. 10 instead of the one shown in FIG. 1. This power conversion device 10 includes a connection path 200, a switch 201, and a current sensor 202 instead of the connection path 60, the neutral point switch 61, and the current sensor 62. A first end of the connection path 200 is connected to an emitter of an upper arm switch and a collector of a lower arm switch of a part of the three phases. In the example shown in FIG. 10, the first end of the connection path 200 is connected to the U phase. A second end of the connection path 200 is connected to the neutral point inverter terminal TIM. The switch 201 and the current sensor 202 are provided on the connection path 200.
[0084] The control device 70 performs the voltage equalization control and temperature rise control described above. Here, the neutral point switch 61 is replaced with a switch 201. In addition, in the voltage equalization control and temperature rise control, the U-phase upper and lower arm switches QUH and QUL are maintained off, and switching control of the V- and W-phase upper and lower arm switches QVH, QVL, QWH, and QWL is performed.
[0085] The configuration shown in FIG. 10 also makes it possible to reduce radiation noise associated with switching control and noise flowing to the body ground BG.
[0086] The upper and lower arm switches constituting the inverter are not limited to IGBTs, and may be, for example, N-channel MOSFETs.
[0087] Instead of the storage battery, for example, an electric double layer capacitor may be used.
[0088] The moving body on which the power conversion device is mounted is not limited to a vehicle, but may be, for example, an aircraft or a ship. For example, if the moving body is an aircraft, a rotating electric machine installed in the aircraft serves as the flight power source of the aircraft, and if the moving body is a ship, a rotating electric machine installed in the ship serves as the navigation power source of the ship. Furthermore, the mounting of the power conversion device is not limited to a moving body.
[0089] The control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be realized by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. In addition, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer. [Explanation of symbols]
[0090] 10...power conversion device, 21, 22...first and second storage batteries, 30...inverter, 40...rotating electric machine, 60...connection path, 61...neutral point switch, 70...control device, 100...battery case, 110...common case.
Claims
1. an inverter (30) having a series-connected body of upper and lower arm switches (QUH to QYL), the series-connected body being connected in parallel to a series-connected body of a first storage unit (21) and a second storage unit (22); a rotating electric machine (40) having windings (41U to 41Y) electrically connected to the inverter; a neutral point wiring (60, 80M, 60M, 81M, 60I) electrically connecting a negative electrode side of the first storage unit and a positive electrode side of the second storage unit to a neutral point of the winding; a control unit (70) that performs switching control of the upper and lower arm switches so that a current flows between the first storage unit and the second storage unit via the inverter, the winding, and the neutral point wiring; and a case (120, 130, 150) that houses at least the inverter and has a shielding function. At least a portion of the neutral wiring is accommodated in the case, In the above case, a first case (120, 150) that houses the inverter; a second case (130) arranged apart from the first case and housing the rotating electric machine, The power conversion device (10) includes a shielded wire (91) that covers a neutral point case-to-case wiring (81M), which is a portion of the neutral point wiring between a portion (60M) housed in the second case and a portion (60I) housed in the first case, and electrically connects the second case and the first case.
2. a power wiring is provided for electrically connecting a connection point of the upper and lower arm switches and an end of the winding opposite to the neutral point side, in each phase; 2. The power conversion device of claim 1, wherein the shielded wire covers a portion (81U to 81W) of the power wiring between the portion housed in the second case and the portion housed in the first case, together with the neutral point case-to-case wiring.
3. A neutral switch (61) is provided on the neutral wiring, The control unit switches the neutral point switch on when performing the switching control, The first case (150) has a bottom plate portion (151) and a wall portion (152) provided on a peripheral portion of the bottom plate portion, The neutral wiring is led into the first case via a terminal (TM) provided on the wall portion, The power conversion device according to claim 1 , wherein the neutral point switch is provided on an inner surface of the wall portion near the terminal.
4. an inverter (30) having a series-connected body of upper and lower arm switches (QUH to QYL), the series-connected body being connected in parallel to a series-connected body of a first storage unit (21) and a second storage unit (22); a rotating electric machine (40) having windings (41U to 41Y) electrically connected to the inverter; a neutral point wiring (60, 80M, 60M, 81M, 60I) electrically connecting a negative electrode side of the first storage unit and a positive electrode side of the second storage unit to a neutral point of the winding; a control unit (70) that performs switching control of the upper and lower arm switches so that a current flows between the first storage unit and the second storage unit via the inverter, the winding, and the neutral point wiring; and a case (100, 110) that houses at least the inverter and has a shielding function. At least a portion of the neutral wiring is accommodated in the case, In the above case, A first case (110) that houses the inverter; a second case (100) arranged apart from the first case and housing the first storage unit and the second storage unit; The power conversion device (10) includes a shielded wire (90) that covers a battery-side case-to-case wiring (80M), which is a portion of the neutral wiring between a portion housed in the second case and a portion housed in the first case (60), and electrically connects the first case and the second case.
5. The power conversion device of claim 4, wherein the shielded wire covers, together with the battery side case wiring, a portion (80H) of the wiring electrically connecting the positive electrode side of the first storage unit and the high potential side terminal of the upper arm switch that is not housed in the first case and the second case, and a portion (80L) of the wiring electrically connecting the negative electrode side of the second storage unit and the low potential side terminal of the lower arm switch that is not housed in the first case and the second case.
6. an inverter (30) having a series-connected body of upper and lower arm switches (QUH to QYL), the series-connected body being connected in parallel to a series-connected body of a first storage unit (21) and a second storage unit (22); a rotating electric machine (40) having windings (41U to 41Y) electrically connected to the inverter; a neutral point wiring (60, 80M, 60M, 81M, 60I) electrically connecting a negative electrode side of the first storage unit and a positive electrode side of the second storage unit to a neutral point of the winding; a control unit (70) that performs switching control of the upper and lower arm switches so that a current flows between the first storage unit and the second storage unit via the inverter, the winding, and the neutral point wiring; a case (150) that houses the inverter, the first storage unit, and the second storage unit and has a shielding function; At least a portion of the neutral wiring is housed within the case.
7. an inverter (30) having a series-connected body of upper and lower arm switches (QUH to QYL), the series-connected body being connected in parallel to a series-connected body of a first storage unit (21) and a second storage unit (22); a rotating electric machine (40) having windings (41U to 41Y) electrically connected to the inverter; a neutral point wiring (60M, 81M, 60I) electrically connecting a negative electrode side of the first storage unit and a positive electrode side of the second storage unit to a neutral point of the winding; a control unit (70) that performs switching control of the upper and lower arm switches so that a current flows between the first storage unit and the second storage unit via the inverter, the winding, and the neutral point wiring; a case (150) that accommodates the inverter, the first power storage unit, and the second power storage unit, the case is made of a non-metallic material; a high potential side wiring electrically connecting a positive electrode side of the first power storage unit and a high potential side terminal of the upper arm switch, a low potential side wiring electrically connecting a negative electrode side of the second power storage unit and a low potential side terminal of the lower arm switch, and at least a part of the neutral point wiring are housed in the case, The power conversion device (10) includes a shield wire that covers the high potential side wiring, the low potential side wiring, and the neutral point wiring within the case.
8. an inverter (30) having a series-connected body of upper and lower arm switches (QUH to QYL), the series-connected body being connected in parallel to a series-connected body of a first storage unit (21) and a second storage unit (22); a rotating electric machine (40) having windings (41U to 41Y) electrically connected to the inverter; a neutral point wiring (60, 80M, 60M, 81M, 60I) electrically connecting a negative electrode side of the first storage unit and a positive electrode side of the second storage unit to a neutral point of the winding; a control unit (70) that performs switching control of the upper and lower arm switches so that a current flows between the first storage unit and the second storage unit via the inverter, the winding, and the neutral point wiring; a case (110, 140) that houses the inverter and the rotating electric machine and has a shielding function; At least a portion of the neutral wiring is accommodated in the case, a bypass wiring (63) having a first end electrically connected to the neutral point and housed in the case; A first capacitor (32A) and a second capacitor (32B) provided in the case (110), Within the case, a high potential terminal side of the upper arm switch and a low potential terminal side of the lower arm switch are electrically connected to a second end of the bypass wiring, A power conversion device (10) in which the neutral point wiring, from a middle portion to the first power storage unit and the second power storage unit side, is disposed outside the case.
9. The power converter according to claim 8, further comprising a third capacitor (35) provided in the bypass wiring.
10. an inverter (30) having a series-connected body of upper and lower arm switches (QUH to QYL), the series-connected body being connected in parallel to a series-connected body of a first storage unit (21) and a second storage unit (22); a rotating electric machine (40) having windings (41U to 41Y) electrically connected to the inverter; a neutral point wiring (60, 80M, 60M, 81M, 60I) electrically connecting a negative electrode side of the first storage unit and a positive electrode side of the second storage unit to a neutral point of the winding; a control unit (70) that performs switching control of the upper and lower arm switches so that a current flows between the first storage unit and the second storage unit via the inverter, the winding, and the neutral point wiring; and a case (100, 110, 120, 130, 140, 150) that houses at least the inverter and has a shielding function, At least a portion of the neutral wiring is accommodated in the case, A first capacitor (32A) and a second capacitor (32B) are provided in the case, In the case, the high potential terminal side of the upper arm switch and the neutral point wiring are electrically connected by the first capacitor, A power conversion device (10) in the case, wherein the low potential side terminal side of the lower arm switch and the neutral point wiring are electrically connected by the second capacitor.
11. an inverter (30) having a series-connected body of upper and lower arm switches (QUH to QYL), the series-connected body being connected in parallel to a series-connected body of a first storage unit (21) and a second storage unit (22); a rotating electric machine (40) having windings (41U to 41Y) electrically connected to the inverter; a neutral point wiring (60, 80M, 60M, 81M, 60I) electrically connecting a negative electrode side of the first storage unit and a positive electrode side of the second storage unit to a neutral point of the winding; a control unit (70) that performs switching control of the upper and lower arm switches so that a current flows between the first storage unit and the second storage unit via the inverter, the winding, and the neutral point wiring; and a case (100, 110, 120, 130, 140, 150) that houses at least the inverter and has a shielding function, At least a portion of the neutral wiring is accommodated in the case, a first coil (34A) provided on a high potential side wiring that electrically connects a positive electrode side of the first storage unit and a high potential side terminal of the upper arm switch; A second coil (34B) provided in the neutral wiring; a third coil (34C) provided on a low potential side wiring that electrically connects a negative electrode side of the second storage unit and a low potential side terminal of the lower arm switch; A common mode choke (33) having a common magnetic core around which the first coil, the second coil, and the third coil are wound.
12. A neutral switch (61) is provided on the neutral wiring, The control unit switches the neutral point switch on when performing the switching control, The power conversion device according to any one of claims 1 to 11, wherein the neutral point switch is provided on the neutral point wiring closer to the neutral point than a central portion.
Citation Information
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