control system

Abstract

To provide a control system that can reduce noise. [Solution] The control system 100 includes a first battery 10a, a second battery 10b connected in series with the first battery 10a, a multiphase rotating electric machine 40, a first inverter 20, and a second inverter 30. The control system 100 also includes a connection point P2 which is the neutral point of the windings 41U, 41V, and 41W of each phase of the rotating electric machine 40, and a third B switch SW3B which switches the energization and disconnection of a third electrical path 23 connecting the connection point P1 between the first battery 10a and the second battery 10b. In the third electrical path 23, the distance from the connection point P2 to the third B switch SW3B is shorter than the distance from the connection point P1 between the first battery 10a and the second battery 10b to the third B switch SW3B.

Description

Technical Field

[0006] , ,

[0001] The present disclosure relates to a control system.

Background Art

[0002] Conventionally, there has been a control system that connects the neutral point of the winding of a rotating electrical machine to the midpoint of batteries connected in series and changes the connection state of the batteries using the winding of the rotating electrical machine. Such a control system is described in, for example, Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the connection switch that cuts off the energization of the electrical path connecting the neutral point of the winding and the midpoint of the battery is turned off, the potential of the electrical path from the connection switch to the neutral point may remain high. In this case, there has been a problem that the electrical path from the connection switch to the neutral point is likely to radiate noise and may become an antenna that is likely to receive noise.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a control system capable of reducing noise.

Means for Solving the Problems

[0006] The control system that solves the above problems is a control system that can change the connection state of a first energy storage unit and a second energy storage unit for a multiphase rotating electric machine, and comprises a neutral point connection switch that switches the energization and disconnection of a neutral point connection path connecting the neutral point of the windings of each phase of the rotating electric machine and the connection point between the first energy storage unit and the second energy storage unit, wherein the distance from the first end of the neutral point connection path connected to the neutral point to the neutral point connection switch is shorter than the distance from the second end of the neutral point connection path connected to the connection point to the neutral point connection switch.

[0007] This allows for a shorter neutral point connection path from the neutral point to the neutral point connection switch, which can potentially have a higher potential. Therefore, by shortening the neutral point connection path, which is a source of noise radiation, noise can be reduced. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram showing the configuration of the control system. [Figure 2] A diagram showing the on / off states of each switch in driving mode (H drive state). [Figure 3] A diagram showing the on / off states of each switch in driving mode (Y drive state). [Figure 4] A diagram showing the on / off states of each switch in series charging mode. [Figure 5] A diagram showing the on / off states of each switch in parallel charging mode. [Figure 6] A plan view showing the arrangement of modules. [Figure 7] A side view showing the arrangement of modules. [Figure 8] A diagram showing the configuration of the control system of the second embodiment. [Figure 9] A plan view showing the arrangement of modules in a modified example. [Figure 10] A plan view showing the arrangement of modules in a modified example. [Figure 11] A plan view showing the arrangement of modules in a modified example. [Figure 12] A plan view showing the arrangement of modules in a modified example. [Figure 13] A side view showing the arrangement of modules in a modified example. [Modes for carrying out the invention]

[0009] Multiple embodiments will be described with reference to the drawings. In multiple embodiments, functionally and / or structurally corresponding and / or related parts may be given the same reference numerals. For corresponding and / or related parts, refer to the descriptions of other embodiments.

[0010] (First Embodiment) Hereinafter, a first embodiment of the control system described herein will be explained with reference to the drawings. The control system 100 of this embodiment is installed in electric vehicles such as electric cars and hybrid vehicles. As shown in Figure 1, the control system 100 of this embodiment is for connecting a battery pack 10 to a rotating electric machine 40 and includes a first inverter 20, a second inverter 30, and a control device 50.

[0011] The battery pack 10 is configured by connecting a first battery 10a and a second battery 10b in series, with the first battery 10a and the second battery 10b each being a single battery cell or a series connection of multiple battery cells. The battery cells are, for example, secondary batteries such as lithium-ion batteries. The terminal voltage of the battery pack 10 is, for example, 800V. The terminal voltage of the first battery 10a and the second battery 10b is, for example, 400V. The first battery 10a corresponds to the first energy storage unit, and the second battery 10b corresponds to the second energy storage unit.

[0012] The first inverter 20 and the second inverter 30 are devices that convert the DC power supplied from the battery pack 10 into three-phase AC power and supply it to the rotating electric machine 40. The first inverter 20 and the second inverter 30 in this embodiment constitute a power converter.

[0013] The first inverter 20 includes a series connection of a first upper arm switch SUHa of the U phase and a first lower arm switch Sula of the U phase, a series connection of a first upper arm switch SVHa of the V phase and a first lower arm switch SVLa of the V phase, and a series connection of a first upper arm switch SWHa of the W phase and a first lower arm switch SWLa of the W phase. Hereinafter, these are collectively referred to as switches SUHa to SWLa.

[0014] Similarly, the second inverter 30 includes a series connection of a second upper arm switch SUHb of the U phase and a second lower arm switch SULb of the U phase, a series connection of a second upper arm switch SVHb of the V phase and a second lower arm switch SVLb of the V phase, and a series connection of a second upper arm switch SWHb of the W phase and a second lower arm switch SWLb of the W phase. Hereinafter, these are collectively referred to as switches SUHb to SWLb.

[0015] In this embodiment, voltage-controlled semiconductor switching elements are used as the switches SUHa to SWLa and SUHb to SWLb, and more specifically, IGBTs are used. In this case, the high-potential side terminals of the switches SUHa to SWLa and SUHb to SWLb are collectors, and the low-potential side terminals are emitters.Moreover, freewheel diodes DUHa, DVHa, DWHa, DULa, DVLa, DWLa, DUHb, DVHb, DWHb, DULb, DVLb, and DWLb are connected in antiparallel to the switches SUHa, SVHa, SWHa, SULa, SVLa, SWLa, SUHb, SVHb, SWHb, SULb, SVLb, and SWLb.

[0016] The collectors of the first upper arm switches SUHa, SVHa, and SWHa of each phase and the collectors of the second upper arm switches SUHb, SVHb, and SWHb of each phase are electrically connected by a positive bus bar 11 as a high-potential side connection line such as a bus bar. Also, the emitters of the first lower arm switches SULa, SVLa, and SWLa of each phase and the emitters of the second lower arm switches SULb, SVLb, and SWLb of each phase are electrically connected by a negative bus bar 12 as a low-potential side connection line such as a bus bar.

[0017] The positive electrode terminal of the battery pack 10 (the positive electrode terminal of the first battery 10a) is electrically connected to the positive bus bar 11, and the negative electrode terminal of the battery pack 10 (the negative electrode terminal of the second battery 10b) is electrically connected to the negative bus bar 12. The battery pack 10 is electrically connected to each of the bus bars 11 and 12 on the side opposite to the second inverter 30 with respect to the first inverter 20.

[0018] The rotating electric machine 40 is an in-vehicle main machine. The rotor of the rotating electric machine 40 is capable of power transmission to the driving wheels of the vehicle. In the present embodiment, the rotating electric machine 40 is a permanent magnet field type synchronous machine. The rotor includes permanent magnets (for example, neodymium magnets) as field poles.

[0019] The rotating electric machine 40 includes a stator 41. The stator 41 includes a U-phase winding 41U, a V-phase winding 41V, and a W-phase winding 41W as armature windings. Each of the phase windings 41U, 41V, and 41W is arranged with an electrical angle shift of 120° from each other. Each of the phase windings 41U, 41V, and 41W is open-connected, and both ends of each of the phase windings 41U, 41V, and 41W are electrically connected to the first inverter 20 or the second inverter 30.

[0020] Specifically, in each phase, the first upper arm switches SUHa, SVHa, SWHa and the first lower arm switches SULa, SVLa, SWLa corresponding to the phase are electrically connected to the first ends of the phase windings 41U, 41V, 41W. Also, in each phase, the second upper arm switches SUHb, SVHb, SWHb and the second lower arm switches SULb, SVLb, SWLb corresponding to the phase are electrically connected to the second ends of the phase windings 41U, 41V, 41W.

[0021] The control system 100 includes a changeover switch 13. The changeover switch 13 is located between the first inverter 20 and the second inverter 30 on the positive busbar 11. When the changeover switch 13 is turned on, it electrically conducts electricity between the first inverter 20 and the second inverter 30, and when it is turned off, it electrically disconnects electricity between the first inverter 20 and the second inverter 30. The changeover switch 13 is controlled by the control device 50. The changeover switch 13 is provided to switch the drive state of the control system 100, as will be described later. The changeover switch 13 is, for example, a relay switch.

[0022] By switching the changeover switch 13 on or off, the drive state of the control system 100 can be switched between a Y drive state and an H drive state. More specifically, by turning off the changeover switch 13, turning on the second upper arm switches SUHb, SVHb, SWHb for each phase, and turning off the lower arm switches SULb, SVLb, SWLb for each phase, the control system 100 can be set to a Y drive state. In the Y drive state, the phase windings 41U, 41V, 41W are Y-connected via the second inverter 30. In the Y drive state, the first inverter 20 controls the rotating electric machine 40. On the other hand, by turning on the changeover switch 13, the control system 100 can be set to an H drive state. In the H drive state, the first inverter 20 and the second inverter 30 work together to control the rotating electric machine 40.

[0023] The control system 100 includes a first capacitor 14 and a second capacitor 15. The first capacitor 14 and the second capacitor 15 are smoothing capacitors. The first terminal of the first capacitor 14 is electrically connected between the positive terminal of the first battery 10a and the first inverter 20 on the positive bus 11. The second terminal of the first capacitor 14 is electrically connected between the negative terminal of the second battery 10b and the first inverter 20 on the negative bus 12. The first terminal of the second capacitor 15 is electrically connected to the positive bus 11 on the side opposite to the first inverter 20 relative to the second inverter 30. The second terminal of the second capacitor 15 is electrically connected to the negative bus 12 on the side opposite to the first inverter 20 relative to the second inverter 30. Note that the second capacitor 15 may be omitted.

[0024] The control system 100 includes a positive-side main switch SMRH that switches the energization and de-energization of the positive-side busbar 11 connecting the first battery 10a and the first inverter 20. The control system 100 also includes a negative-side main switch SMRL that switches the energization and de-energization of the negative-side busbar 12 connecting the second battery 10b and the first inverter 20.

[0025] In this embodiment, each main switch SMRH and SMRL is a mechanical relay. When each main switch SMRH and SMRL is turned off, it prevents the flow of current in both directions, and when it is turned on, it allows the flow of current in both directions. Note that the positive terminal main switch SMRH and the negative terminal main switch SMRL are not limited to mechanical relays, but may also be semiconductor switching elements, for example.

[0026] The first battery 10a and the second battery 10b can be charged by an external charger 200 located outside the vehicle. The external charging-related configuration of the control system 100 will now be described.

[0027] The control system 100 includes an external charging mechanism 60. The external charging mechanism 60 includes an inlet (charging port) 62 and a relay 61. The inlet 62 is connected to the battery pack 10 and the first inverter 20 via the relay 61 at each bus 11, 12. When the main switches SMRH, SMRL and the relay 61 are turned on, power from the external power supply 210 of the external charger 200 is supplied to the battery pack 10 via the inlet 62.

[0028] The external charger 200 is, for example, a stationary charger. External charging is performed when the inlet 62 is electrically connected to the external charger 200. The external charger 200 comprises an external power supply 210 and a connector 220. The connector 220 is configured to be connectable to the vehicle's inlet 62. The external power supply 210 is, for example, a DC power supply, but it may also be an AC power supply. In this case, an AC / DC converter is required.

[0029] For example, if the external charger 200 is connected to the control system 100 by a user or operator, and the first battery 10a and the second battery 10b are charged by the external charger 200, the relay 61 is switched on by the control device 50. On the other hand, if charging by the external charger 200 is not performed or the external charger 200 is not connected, the relay 61 is switched off by the control device 50.

[0030] The control system 100 includes a first switch SW1, a second switch SW2, a third A switch SW3A, and a third B switch SW3B as switches for switching the connection state of the first battery 10a and the second battery 10b to either a series connection state in which they are connected in series with the external charger 200, or a parallel connection state. The parallel connection state is a connection state in which the second battery 10b is connected in parallel with the first battery 10a via the rotating electric machine 40.

[0031] In this embodiment, the first switch SW1, the second switch SW2, the third A switch SW3A, and the third B switch SW3B are mechanical relays. When the first switch SW1, the second switch SW2, the third A switch SW3A, and the third B switch SW3B are turned off, they block the flow of current in both directions, and when they are turned on, they allow the flow of current in both directions. Note that the first switch SW1, the second switch SW2, the third A switch SW3A, and the third B switch SW3B are not limited to mechanical relays, but may be semiconductor switching elements, for example.

[0032] The first switch SW1 is located in the first electrical path 21 that connects the negative terminal of the first battery 10a and the positive terminal of the second battery 10b. When the first switch SW1 is turned on, the negative terminal of the first battery 10a and the positive terminal of the second battery 10b are electrically connected. Conversely, when the first switch SW1 is turned off, the negative terminal of the first battery 10a and the positive terminal of the second battery 10b are electrically disconnected.

[0033] The second switch SW2 is located in the second electrical path 22 that connects the negative terminal of the first battery 10a to the negative busbar 12. When the second switch SW2 is turned on, the negative terminal of the first battery 10a and the negative busbar 12 are electrically connected. Conversely, when the second switch SW2 is turned off, the negative terminal of the first battery 10a and the negative busbar 12 are electrically disconnected.

[0034] The third A switch SW3A and the third B switch SW3B are located in the third electrical path 23, which connects the first electrical path 21 to the neutral points of each phase winding 41U, 41V, and 41W in the Y-driven state. More specifically, one end of the third electrical path 23 is connected to connection point P1 on the first electrical path 21, which is on the second battery 10b side of the first switch SW1. The other end of the third electrical path 23 is connected to connection point P2 on the positive side busbar 11, which is on the opposite side of the changeover switch 13 to the second inverter 30. Therefore, in the Y-driven state, when the changeover switch 13 is turned off, and the second upper arm switches SUHb, SVHb, and SWHb for each phase are turned on, and the lower arm switches SULb, SVLb, and SWLb for each phase are turned off, a star connection is established, and the third electrical path 23 is equivalent to being connected to the neutral points of each phase winding 41U, 41V, and 41W.

[0035] The third A switch SW3A is located on the side of the second battery 10b, and the third B switch SW3B is located on the side of the second inverter 30. When both the third A switch SW3A and the third B switch SW3B are turned on, the positive busbar 11 (neutral point in the Y drive state) in the H drive state and the positive terminal of the second battery 10b are electrically connected. On the other hand, when either the third A switch SW3A or the third B switch SW3B is turned off, the positive busbar 11 (neutral point in the Y drive state) in the H drive state and the positive terminal of the second battery 10b are electrically disconnected. In this embodiment, the third B switch SW3B, which is located closest to the neutral point (on the side of the second inverter 30) in the Y drive state, corresponds to the neutral point connection switch. The third electrical path 23 corresponds to the neutral point connection path. Note that it is not necessary to provide both the third A switch SW3A and the third B switch SW3B; the third B switch SW3B alone may suffice.

[0036] In this embodiment, the external charger 200 is either a high-voltage charger or a low-voltage charger. The charging voltage of the high-voltage charger is approximately the same as the terminal voltage of the battery pack 10 (specifically, the rated voltage), for example, 800V. On the other hand, the charging voltage of the low-voltage charger is lower than the rated voltage of the battery pack 10, for example, 400V.

[0037] Therefore, when a high-voltage charger is connected as the external charger 200, the control system 100 switches the connection state of the first battery 10a and the second battery 10b to a series connection state in which they are connected in series with respect to the external charger 200. On the other hand, when a low-voltage charger is connected as the external charger 200, the control system 100 switches the connection state of the first battery 10a and the second battery 10b to a parallel connection state in which they are connected in parallel with respect to the external charger 200.

[0038] The control device 50 is mainly composed of a microcontroller unit (microcomputer) 51, which includes an arithmetic processing unit such as a CPU and storage units such as various types of memory. The functions provided by the microcontroller unit 51 can be provided by software recorded in a physical memory device and a computer that executes it, by software only, by hardware only, or by a combination of both. For example, when the microcomputer is provided by electronic circuits, which are hardware, it can be provided by digital circuits including a large number of logic circuits, or by analog circuits. For example, the arithmetic processing unit of the microcontroller unit 51 executes a program stored in a non-transitory tangible storage medium, which serves as its own storage unit. The program includes, for example, a program that implements functions related to the on / off control of various switches. When the program is executed, the method corresponding to the program is executed. The storage unit is, for example, non-volatile memory. The program stored in the storage unit can be downloaded and updated via a communication network such as the Internet, for example, via OTA (Over The Air).

[0039] As shown in Figure 1, the microcontroller 51 has the functions of a mode determination unit 52 and a switch control unit 53. These functions are realized by the arithmetic processing unit executing a program stored in the memory unit. These functions will be described below.

[0040] The mode determination unit 52 is a function that receives a control mode commanded from a higher-level ECU or the like and determines the content of that control mode. The control mode indicates the control state of various switches (SMRH, SMRL, 13, SUHa~SWLa, SUHb~SWLb, SW1, SW2, SW3A, SW3B, 61) that make up the control system 100. Examples of control modes include a driving mode for driving the vehicle and a charging mode for charging the battery pack 10 by an external charger 200.

[0041] The charging modes of this embodiment include a series charging mode and a parallel charging mode. The series charging mode is set when a high-voltage charger is connected as the external charger 200, and the parallel charging mode is set when a low-voltage charger is connected as the external charger 200.

[0042] The switch control unit 53 controls the on / off state of various switches (SMRH, SMRL, 13, SUHa~SWLa, SUHb~SWLb, SW1, SW2, SW3A, SW3B, 61) according to the control mode determined by the mode determination unit 52.

[0043] For example, when the microcontroller 51, acting as the switch control unit 53, determines that the commanded control mode is the driving mode, it controls the switching of switches SUHa~SWLa, SUHb~SWLb to control the torque of the rotating electric machine 40 to the commanded torque based on the detected values ​​of various sensors (voltage sensor, current sensor, rotation angle sensor, etc.) not shown, thereby driving the rotating electric machine 40 and driving the vehicle. The commanded torque is input from, for example, a higher-level ECU.

[0044] More specifically, the switch control unit 53 selects whether the drive state of the control system 100 should be in the Y drive state or the H drive state during the driving mode. The switch control unit 53 selects which state to set based, for example, on the operating point of the rotating electric machine 40, which is determined by the electrical angular velocity calculated based on the electrical angle and the commanded torque.

[0045] When the H drive state is selected, the switch control unit 53 turns on the changeover switch 13 as shown in Figure 2, and performs PWM control (pulse width modulation control) for each switch SUHa to SWLa of the first inverter 20, as well as PWM control for each switch SUHb to SWLb of the second inverter 30.

[0046] On the other hand, when the switch control unit 53 selects the Y drive state, as shown in Figure 3, it turns off the changeover switch 13 and performs ON-fixed control on each phase upper arm switch SUHb, SVHb, SWHb of the second inverter 30, and OFF-fixed control on each phase lower arm switch SULb, SVLb, SWLb of the second inverter 30. As a result, each phase winding 41U, 41V, 41W is star-connected via the second inverter 30. Note that in the figure, switches that are OFF-fixed (or turned off) are indicated with an "×".

[0047] In this state, the switch control unit 53 performs PWM control on each switch SUHa to SWLa of the first inverter 20. By appropriately switching between the Y drive state and the H drive state in this way and executing switching control, the control system 100 is made more powerful and efficient.

[0048] During driving mode, as shown in Figures 2 and 3, the switch control unit 53 turns on the main switches SMRH and SMRL and the first switch SW1, and turns off the second switch SW2, the third A switch SW3A, and the third B switch SW3B. In other words, they are connected in series. Relay 61 is also turned off.

[0049] Furthermore, if the switch control unit 53 determines that the commanded control mode is the series charging mode, it connects the first battery 10a and the second battery 10b in series with the external charger 200 while the high-voltage charger is connected as the external charger 200 during the series charging mode. That is, as shown in Figure 4, the switch control unit 53 turns on the relay 61 and the first switch SW1, and turns off the main switches SMRH, SMRL, the second switch SW2, the third A switch SW3A, and the third B switch SW3B. At that time, the control device 50 turns off the changeover switch 13 and performs off-fix control for the switches SUHa~SWLa, SUHb~SWLb of the first and second inverters 20 and 30, respectively.

[0050] Furthermore, if the switch control unit 53 determines that the commanded control mode is parallel charging mode, it connects the first battery 10a and the second battery 10b in parallel to the external charger 200 while the low-voltage charger is connected as the external charger 200 during parallel charging mode. That is, as shown in Figure 5, the switch control unit 53 turns on the relay 61, the main switch SMRH, the second switch SW2, the third A switch SW3A, and the third B switch SW3B, and turns off the main switch SMRL, the first switch SW1, and the changeover switch 13. In addition, the switch control unit 53 performs on-fixed control for the upper arm switches SUHa, SVHa, SWHa, SUHb, SVHb, and SWHb of the first and second inverters 20 and 30, and performs off-fixed control for the lower arm switches SULa, SVLa, SWLa, SULb, SVLb, and SWLb.

[0051] Incidentally, in parallel charging mode, the third electrical path 23 is at a higher potential than the negative terminal bus 12. Therefore, if the third A switch SW3A and the third B switch SW3B are turned off from this state to cut off the power to the third electrical path 23, the potential of the third electrical path 23 from the connection point P2 on the second inverter 30 to the third B switch SW3B may remain high. If the third B switch SW3B is located near the battery pack 10 (for example, inside the battery pack), and the distance of the third electrical path 23 from the connection point P2 to the third B switch SW3B is long, even if there is a second capacitor 15 (smoothing capacitor), it may function as an antenna that radiates (or receives) noise. In particular, in this embodiment, the second inverter 30, which is a noise source, and the third electrical path 23 are directly connected, making it highly likely that they will become a noise radiation source.

[0052] Therefore, in this embodiment, as shown in Figure 1, the third B switch SW3B is located near the second inverter 30. Furthermore, in the third electrical path 23, the distance from the connection point P2 on the second inverter 30 side to the third B switch SW3B is configured to be shorter than the distance from the third B switch SW3B to the connection point P1 on the battery pack 10 side.

[0053] Furthermore, as shown in Figure 6, the changeover switch 13, the first inverter 20, the second inverter 30, the first capacitor 14, the second capacitor 15, and the third B switch SW3B are housed in a conductive inverter case 71.

[0054] Here, we will explain these arrangements with reference to Figure 6. The inverter case 71 is formed in a roughly rectangular box shape. Figure 6 is a schematic diagram showing the arrangement of each component inside the inverter case 71. In Figure 6, the inside of the inverter case 71 is viewed from the vertical direction. The vertical direction is the direction perpendicular to the plane of the inverter case 71, which is the Z direction in the figure. The planar direction of the inverter case 71 is shown in the figure as the X direction and the Y direction. The X direction and the Y direction are perpendicular to the Z direction, and the Y direction is perpendicular to the X direction.

[0055] As shown in Figure 6, within the inverter case 71, a first inverter 20 (module, hereinafter the same) which integrates switches SUHa to SWLa, and a second inverter 30 (module, hereinafter the same) which integrates switches SUHb to SWLb are arranged side by side in the planar direction of the inverter case 71. In this embodiment, the first inverter 20 and the second inverter 30 are arranged side by side in the Y direction (up and down direction in Figure 6) of the inverter case 71.

[0056] Similarly, the first capacitor 14 (module, hereafter the same) and the second capacitor 15 (module, hereafter the same) are arranged side by side in the Y direction. In addition, in the X direction (left-right direction in Figure 6) of the inverter case 71, the first inverter 20 and the first capacitor 14 are arranged side by side, and the second inverter 30 and the second capacitor 15 are arranged side by side in the same manner.

[0057] The changeover switch 13 and the third B switch SW3B are located between the first inverter 20 and the second inverter 30. In the X direction, the changeover switch 13 and the third B switch SW3B are located adjacent to each other.

[0058] Furthermore, as shown in Figure 7, a cooling device 72 for cooling each module is located on the bottom surface of the inverter case 71 (the surface opposite to the surface where the first inverter 20, etc., is arranged). In this embodiment, the cooling device 72 refers not to the device that delivers the refrigerant (such as a pump), but to the refrigerant passages through which the refrigerant circulates and components that cool the circuit elements, such as heat sinks.

[0059] The cooling device 72 is positioned in an area overlapping with the changeover switch 13 and the third B switch SW3B so as to cool at least the changeover switch 13 and the third B switch SW3B. In this embodiment, in addition to the changeover switch 13 and the third B switch SW3B, the cooling device 72 is positioned in an area overlapping with the area where the first inverter 20, the second inverter 30, the first capacitor 14 and the second capacitor 15 are located so as to cool them.

[0060] The main switches SMRH, SMRL, the first switch SW1, the second switch SW2, and the third A switch SW3A are housed within the battery pack 80 (see Figure 1), which also houses the battery pack 10. More specifically, they are all housed together in a junction box located within the battery pack 80.

[0061] On the other hand, the rotating electric machine 40 is provided separately from the inverter case 71 and the battery pack 80. More specifically, the rotating electric machine 40 is constructed by housing the rotor and stator in a housing for rotating electric machines.

[0062] The control system 100 of this embodiment, configured as described above, provides the following effects.

[0063] In the third electrical path 23, the distance from connection point P2 (neutral point in the Y-driven state) to the third B switch SW3B is shorter than the distance from the third B switch SW3B to connection point P1 between the first battery 10a and the second battery 10b. This makes it possible to shorten the distance from connection point P2 to the third B switch SW3B, which tends to maintain a higher potential compared to the negative terminal bus 12 when the third B switch SW3B is turned off. Therefore, the third electrical path 23 (the third electrical path 23 from connection point P2 to the third B switch SW3B), which could be a source of noise radiation, can be shortened, making it less likely to radiate noise. In other words, the third electrical path 23, which could act as an antenna, can be shortened, making it less likely to radiate noise.

[0064] The third B switch SW3B is housed in a conductive inverter case 71. As a result, the third electrical path 23 from the connection point P2 (neutral point in the Y drive state) to the third B switch SW3B is not wired outside the inverter case 71, thereby suppressing noise radiation.

[0065] The changeover switch 13 and the third B switch SW3B are adjacent to each other, and both are cooled by the cooling device 72. This eliminates the need to provide separate cooling devices 72 for the changeover switch 13 and the third B switch SW3B, allowing for miniaturization.

[0066] In the planar direction of the inverter case 71, a changeover switch 13 and a third B switch SW3B are provided between the first inverter 20 and the second inverter 30. As a result, as shown in Figure 6, the positive-side busbar 11 on which the changeover switch 13 is provided, the negative-side busbar 12 connecting the first inverter 20 and the second inverter 30, and the third electrical path 23 on which the third B switch SW3B is provided can be wired together as a single unit. In other words, wiring connections can be made easily. In addition, the wiring can be shortened to reduce inductance and suppress heat generation.

[0067] The third B switch SW3B is positioned next to the second capacitor 15. More specifically, the first inverter 20 and the first capacitor 14 are positioned adjacent to each other in the longitudinal direction, and the second inverter 30 and the second capacitor 15 are also positioned adjacent to each other. This shortens the electrical path connecting the first inverter 20 and the first capacitor 14, and also shortens the electrical path connecting the second inverter 30 and the second capacitor 15. In addition, the changeover switch 13 and the third B switch SW3B are positioned adjacent to each other between the first capacitor 14 and the second capacitor 15. This makes it possible to shorten the wiring between the second capacitors 15 and 2 capacitors 15. This makes it possible to reduce the inductance caused by the wiring. Furthermore, these modules can be cooled together by the cooling device 72, enabling miniaturization.

[0068] (Second Embodiment) The configuration of the control system 100 in the first embodiment may be modified. A second embodiment in which the configuration of the control system 100 is modified will be described below.

[0069] In the second embodiment, as shown in Figure 8, the second inverter 30 is removed from the control system 100 of the first embodiment, and the phase windings 41U, 41V, and 41W of the rotating electric machine 40 are connected in a star configuration. Consequently, the changeover switch 13 and the second capacitor 15 are removed. In addition, the neutral point of the rotating electric machine 40 is set to connection point P2, to which one end of the third electrical path 23 is connected. Due to these changes, the H drive state cannot be selected in the second embodiment.

[0070] Furthermore, this configuration allows the third B switch SW3B to be positioned closer to the rotating electric machine 40 than the first inverter 20. In other words, it is positioned near the rotating electric machine 40 so that the electrical path from the neutral point (connection point P2) to the third B switch SW3B is not long. This shortens the third electrical path 23 (the third electrical path 23 from connection point P2 to the third B switch SW3B), which could be a source of noise radiation, making it less likely for noise to be radiated.

[0071] As shown by the dashed line in Figure 8, the third B switch SW3B is housed inside the conductive rotating electric machine case 90, which also houses the windings 41U, 41V, 41W, etc., for each phase of the rotating electric machine 40. This allows the third electrical path 23 from the neutral point (connection point P2) to the third B switch SW3B to be housed inside the rotating electric machine case 90, thereby suppressing noise radiation.

[0072] (modified version) In the above embodiment, the changeover switch 13, the first inverter 20, the second inverter 30, the first capacitor 14, the second capacitor 15, and the third B switch SW3B were housed in one inverter case 71. As a variation, some of these components may be housed in separate cases. For example, the first inverter 20 and the first capacitor 14 may be housed in one case, and the changeover switch 13, the second inverter 30, the second capacitor 15, and the third B switch SW3B may be housed in one case.

[0073] In the above embodiment, the main switches SMRH, SMRL, the first switch SW1, the second switch SW2, and the third A switch SW3A were housed within the battery pack 80. Alternatively, some of these elements may be housed in separate cases. For example, they may be housed in a junction box and placed outside the battery pack 80.

[0074] In the above embodiment, the arrangement of the third B switch SW3B and the like may be arbitrarily changed. For example, as shown in Figure 9, in the first embodiment it was arranged between the first inverter 20 and the second inverter 30, but it may also be arranged outside the second inverter 30 (outside in the Y direction). Alternatively, as shown in Figure 10, it may also be arranged outside the second capacitor 15 (outside in the Y direction). Alternatively, as shown in Figure 11, it may be arranged in the X direction in the same way as the first inverter 20 and the like. In this case, it is desirable that the center position of the third B switch SW3B in the Y direction be between the first inverter 20 and the second inverter 30.

[0075] Furthermore, as shown in Figures 12 and 13, for example, the first inverter 20 and the second inverter 30 may be arranged on top of each other in the vertical direction (Z direction in the figures) of the inverter case 71. Figure 12 is a plan view of the inverter case 71 as seen from the vertical direction, and Figure 13 is a side view of the inverter case 71 as seen from the horizontal direction. As shown in Figure 12, the first inverter 20 and the first capacitor 14 are arranged side by side in the X direction, and the changeover switch 13 and the 3B switch SW3B are arranged side by side adjacent to them. Then, as shown in Figure 13, in the vertical direction, the first inverter 20 and the second inverter 30 are arranged on top of each other with the cooling device 72 in between. Similarly, the first capacitor 14 and the second capacitor 15 are arranged on top of each other with the cooling device 72 in between.

[0076] The following is an addendum regarding the technical ideas that can be derived from the above embodiments and modifications.

[0077] [Configuration 1] In a control system (100) that can change the connection state of a first energy storage unit (10a) and a second energy storage unit (10b) to a multiphase rotating electric machine (40), The rotating electric machine is equipped with a neutral point connection switch (SW3B) that switches between energizing and disconnecting the neutral point connection path (23) that connects the neutral points of the windings (41U, 41V, 41W) of each phase and the connection point between the first and second energy storage units. A control system in which the distance from the first end (P2) connected to the neutral point, of the two ends of the neutral point connection path, to the neutral point connection switch is shorter than the distance from the second end (P1) connected to the connection point, of the two ends of the neutral point connection path, to the neutral point connection switch.

[0078] [Configuration 2] A first inverter (20) is connected to the first end of the windings of each phase, Each phase has a second inverter (30) connected to the second end of the winding, The first inverter and the second inverter are respectively connected to the positive terminal bus (11) connected to the positive terminal of the series connection of the first and second energy storage units. In the positive terminal bus, a changeover switch (13) is provided between the first inverter and the second inverter to switch between energizing and disconnecting the power supply between them. In the positive terminal bus, the series connection between the first energy storage unit and the second energy storage unit is connected to the first inverter side of the changeover switch. In the positive terminal bus, the first end of the neutral point connection path is connected to the second inverter side rather than the changeover switch. The control system according to configuration 1, wherein the neutral point connection switch is housed inside a conductive inverter case (71) that houses at least the second inverter.

[0079] [Configuration 3] The system includes a cooling device (72) for cooling the neutral point connection switch together with the aforementioned changeover switch. The control system according to configuration 1 or 2, wherein the changeover switch is located adjacent to the neutral point connection switch.

[0080] [Structure 4] Inside the inverter case, the first inverter and the second inverter are arranged side by side in the planar direction of the inverter case. The control system according to configuration 2 or 3, wherein the changeover switch and the neutral point connection switch are arranged between the first inverter and the second inverter in the planar direction.

[0081] [Composition 5] Within the inverter case, the first inverter and the second inverter are arranged stacked on top of each other in the thickness direction of the inverter case. The control system according to any one of configurations 2 to 4, wherein the changeover switch and the neutral point connection switch are positioned adjacent to the second inverter in the planar direction of the inverter case.

[0082] [Composition 6] The control system according to any one of configurations 2 to 5, wherein the neutral point connection switch is arranged in parallel with the smoothing capacitors (14, 14) within the inverter case.

[0083] [Composition 7] Each phase is equipped with an inverter (20) connected to the first end of the windings, The second end of each phase winding is star-connected and becomes the neutral point of each phase winding (41U, 41V, 41W) of the rotating electric machine. The control system according to configuration 1, wherein the neutral point connection switch is housed together with the rotating electric machine in a conductive case (90) for the rotating electric machine. [Explanation of Symbols]

[0084] 10...Battery pack, 10a...First battery, 10b...Second battery, 11...Positive busbar, 12...Negative busbar, 13...Changeover switch, 14...First capacitor, 15...Second capacitor, 20...First inverter, 21...First electrical path, 22...Second electrical path, 23...Third electrical path, 30...Second inverter, 40...Rotating electric machine, 41U...U-phase winding, 41V...V-phase winding, 41W...W-phase winding, 50...Control device, 71...Inverter case, 72...Cooling device, 80...Battery pack, 90...Case for rotating electric machine, 100...Control system.

Claims

1. In a control system (100) that can change the connection state of a first energy storage unit (10a) and a second energy storage unit (10b) to a multiphase rotating electric machine (40), The rotating electric machine is equipped with a neutral point connection switch (SW3B) that switches between energizing and disconnecting the neutral point connection path (23) that connects the neutral points of the windings (41U, 41V, 41W) of each phase and the connection point between the first and second energy storage units. A control system in which the distance from the first end (P2) connected to the neutral point, of the two ends of the neutral point connection path, to the neutral point connection switch is shorter than the distance from the second end (P1) connected to the connection point, of the two ends of the neutral point connection path, to the neutral point connection switch.

2. A first inverter (20) is connected to the first end of the windings of each phase, Each phase has a second inverter (30) connected to the second end of the winding, The first inverter and the second inverter are respectively connected to the positive terminal bus (11) connected to the positive terminal of the series connection of the first and second energy storage units. In the positive terminal bus, a changeover switch (13) is provided between the first inverter and the second inverter to switch between energizing and disconnecting the power supply between them. In the positive terminal bus, the series connection between the first energy storage unit and the second energy storage unit is connected to the first inverter side of the changeover switch. In the positive terminal busbar, the first end of the neutral point connection path is connected to the second inverter side rather than the changeover switch. The control system according to claim 1, wherein the neutral point connection switch is housed inside at least the conductive inverter case (71) that houses the second inverter.

3. The system includes a cooling device (72) for cooling the neutral point connection switch together with the aforementioned changeover switch. The control system according to claim 2, wherein the changeover switch is located adjacent to the neutral point connection switch.

4. Inside the inverter case, the first inverter and the second inverter are arranged side by side in the planar direction of the inverter case. The control system according to claim 2 or 3, wherein the changeover switch and the neutral point connection switch are arranged between the first inverter and the second inverter in the planar direction.

5. Within the inverter case, the first inverter and the second inverter are arranged stacked on top of each other in the thickness direction of the inverter case. The control system according to claim 2 or 3, wherein the changeover switch and the neutral point connection switch are positioned adjacent to the second inverter in the planar direction of the inverter case.

6. The control system according to claim 2 or 3, wherein the neutral point connection switch is arranged in parallel with the smoothing capacitors (14, 14) within the inverter case.

7. Each phase is equipped with an inverter (20) connected to the first end of the windings, The second end of each phase winding is star-connected and becomes the neutral point of each phase winding (41U, 41V, 41W) of the rotating electric machine. The control system according to claim 1, wherein the neutral point connection switch is housed together with the rotating electric machine in a conductive case (90) for the rotating electric machine.

Images