Control device, program, and control method

Abstract

This control device (110) is applied to a system provided with a first inverter (30) having first upper and lower arm switches (SAH, SAL) of a plurality of phases, a first motor (40) having first armature windings (41U-41W), a second inverter (50) having second upper and lower arm switches (SBH, SBL) of a plurality of phases, a second motor (60) having second armature windings (61U-61W), a high-potential-side path (32H), and a low-potential-side path (32L). The control device comprises: a temperature increase determination unit (130) that determines whether or not there is a temperature increase request for temperature increase target units (21, 22); a drive determination unit (131) that determines whether or not there is a drive request to generate torque; and a switch control unit (132) that performs temperature increase control of the temperature increase target units and performs switching control of the first and second inverters when it is determined that the temperature increase request is present and the driving request is present.

Description

Control device, program, and control method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-064153, filed on April 11, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a control device, a program, and a control method.

[0003] Conventionally, a power conversion device applied to a system including a power storage unit has been known. The power conversion device includes an inverter and a motor. A control device for the power conversion device drives the motor while controlling the temperature of a unit to be heated. An example of such a power conversion device is disclosed in Patent Document 1.

[0004] Patent No. 7232747

[0005] In the power conversion device, there is a concern that the execution of temperature rise control may affect the output torque of the motor, and it is desirable that this effect be small.

[0006] A primary object of the present disclosure is to provide a control device, a program, and a control method that can reduce the effect of executing temperature rise control on the output torque of a motor.

[0007] The present disclosure relates to a control device that is applied to a system including a first inverter having first upper and lower arm switches of multiple phases, a first motor having a first armature winding electrically connected to low potential side terminals of the first upper arm switches of each phase and high potential side terminals of the first lower arm switches of each phase, a second inverter having second upper and lower arm switches of multiple phases, and a second motor having a second armature winding electrically connected to low potential side terminals of the second upper arm switches of each phase and high potential side terminals of the second lower arm switches of each phase, wherein the system includes: a high potential side path that electrically connects a positive terminal of a power storage unit and the high potential side terminals of the first upper arm switch and the second upper arm switch; and a low potential side path that electrically connects a negative terminal of the power storage unit and the low potential side terminals of the first lower arm switch and the second lower arm switch; a temperature rise determination unit that determines whether or not there is a temperature rise request for a unit to be heated; The system includes a drive determination unit that determines whether there is a drive request to generate torque by at least one of the first motor and the second motor, and a switch control unit that, when it is determined that there is a temperature increase request and that there is a drive request, performs temperature increase control of the temperature increase target part and performs switching control of the first and second inverters so that torque is generated by at least the second motor of the first and second motors.

[0008] When the control device determines that there is a temperature increase request, it executes switching control (hereinafter referred to as temperature increase control) to increase the temperature of the temperature increase target part. Here, when it determines that there is both a temperature increase request and a drive request, the control device executes temperature increase control and drive control. In this case, there is a concern that the execution of temperature increase control may affect the output torque of the motor.

[0009] Therefore, when it is determined that there is a temperature increase request and a drive request, the switch control unit of the present disclosure executes temperature increase control and executes switching control of the first and second inverters to generate torque from at least the second motor of the first and second motors. This allows the torque required for the motors to be output by at least the second motor. This reduces the effect of temperature increase control on the output torque of the motors.

[0010] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a schematic diagram of a vehicle according to a first embodiment, Fig. 2 is a diagram showing an overview of a cooling system, Fig. 3 is a diagram showing the overall configuration of a control system, Fig. 4 is a functional block diagram showing processing by a motor ECU, Fig. 5 is a diagram showing an equivalent circuit, Fig. 6 is a diagram showing an equivalent circuit, Fig. 7 is a functional block diagram showing processing by the motor ECU, Fig. 8 is a diagram showing a waveform of a neutral point command current, Fig. 9 is a flowchart showing the procedure for temperature rise / drive control processing, Fig. 10 is a diagram showing the overall configuration of a system according to a second embodiment, Fig. 11 is a diagram showing the overall configuration of a field current circuit, and Fig. 12 is a flowchart showing the procedure for temperature rise / drive control processing. 13 is an overall configuration diagram of a control system according to a third embodiment, FIG. 14 is a flowchart showing the procedure for temperature rise / drive control processing, FIG. 15 is an overall configuration diagram of a control system according to a fourth embodiment, FIG. 16 is a functional block diagram showing processing by the motor ECU, FIG. 17 is a diagram showing current operating points in inefficient driving, FIG. 18 is a flowchart showing the procedure for temperature rise / drive control processing, FIG. 19 is a flowchart showing the procedure for temperature rise / drive control processing according to a fifth embodiment, FIG. 20 is an overall configuration diagram of a control system according to another embodiment, and FIG. 21 is an overall configuration diagram of a control system according to another embodiment.

[0011] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be designated by the same reference numerals or reference numerals that differ in the hundredth or more digit. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments.

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment of a control device according to the present disclosure will now be described with reference to the drawings. The control device of this embodiment is applied to an electric vehicle.

[0013] 1, a vehicle 10 includes a vehicle body 11 and wheels, which are front wheels 12F and rear wheels 12R.

[0014] The vehicle 10 includes first and second inverters 30, 50 and first and second motors 40, 60 serving as driving power sources. The first inverter 30 is provided as a power conversion circuit for the first motor 40, and the second inverter 50 is provided as a power conversion circuit for the second motor 60. In this embodiment, the first and second motors 40, 60 are on-board motors provided on the vehicle body 11. In this embodiment, the rotational force of the first motor 40 is transmitted to the front wheels 12F, and the rotational force of the second motor 60 is transmitted to the rear wheels 12R. In other words, the vehicle 10 is a four-wheel drive vehicle.

[0015] 1 and 2 , the vehicle 10 includes a control system 20 that performs various driving controls, etc. The control system 20 includes a first storage battery 21 (corresponding to the "first power storage unit"), a second storage battery 22 (corresponding to the "second power storage unit"), the first and second inverters 30, 50, and the first and second motors 40, 60. The first storage battery 21 and the second storage battery 22 serve as power supply sources for driving the first motor 40 and the second motor 60.

[0016] As shown in FIG. 2 , the vehicle 10 includes a device for cooling the control system 20. Specifically, the vehicle 10 includes a circulation path 200 through which coolant circulates, an electric water pump 201, a radiator 202, and an electric fan 203. The water pump 201 is powered and driven to circulate the coolant. In the example shown in FIG. 2 , a first inverter 30, a second inverter 50, a first motor 40, a second motor 60, and first and second storage batteries 21, 22 are arranged in this order in the circulation path 200 downstream of the water pump 201. Note that the arrangement order in the circulation path 200 is not limited to the order shown in FIG. 2 . In this embodiment, the circulation path 200, the coolant circulating through the circulation path 200, and the water pump 201 correspond to a "heat transfer unit."

[0017] A radiator 202 is provided in circulation path 200 between water pump 201 and first and second storage batteries 21, 22. Radiator 202 cools the coolant flowing in via circulation path 200 and supplies the cooled coolant to water pump 201. The coolant flowing into radiator 202 is cooled by wind blown against radiator 202 as vehicle 10 travels and wind blown against radiator 202 by rotating fan 203.

[0018] The vehicle 10 is equipped with a coolant temperature sensor (not shown) that detects the temperature of the coolant flowing through the circulation path 200.

[0019] Next, the control system 20 will be described with reference to Fig. 3. The control system 20 includes a high-potential path 32H and a low-potential path 32L. In the following description, the set of the first inverter 30 and the first motor 40 will be referred to as a first power conversion unit 301, and the set of the second inverter 50 and the second motor 60 will be referred to as a second power conversion unit 302.

[0020] The negative terminal of the first storage battery 21 and the positive terminal of the second storage battery 22 are connected. Each storage battery 21, 22 is a battery pack including a series connection of multiple unit batteries. A unit battery is a single battery cell, which is a single cell, or a series connection of multiple battery cells. In this embodiment, the unit batteries constituting the first storage battery 21 and the second storage battery 22 have the same full charge capacity (specifically, for example, rated full charge capacity) [Ah]. The positive terminal of the first storage battery 21 is connected to an elongated high-potential side path 32H, and the negative terminal of the second storage battery 22 is connected to an elongated low-potential side path 32L. The high-potential side path 32H and the low-potential side path 32L are, for example, electrical paths such as bus bars. The terminal voltages (e.g., rated voltages) of the battery cells constituting the battery pack are set to be the same, for example. The battery cells are, for example, secondary batteries such as lithium-ion batteries. In this embodiment, the terminal voltage (e.g., rated voltage) of the first storage battery 21 is equal to the terminal voltage (e.g., rated voltage) of the second storage battery 22. In this embodiment, the first storage battery 21 and the second storage battery 22 correspond to the "power storage unit."

[0021] The first inverter 30 includes three phases of series-connected upper and lower arm switches. Specifically, the first inverter 30 includes a three-phase first upper arm switch SAH and a three-phase first lower arm switch SAL. A first upper arm diode DAH, which is a freewheeling diode, is connected in anti-parallel to the first upper arm switch SAH, and a first lower arm diode DAL, which is also a freewheeling diode, is connected in anti-parallel to the first lower arm switch SAL. In this embodiment, each of the switches SAH and SAL is an IGBT.

[0022] The first inverter 30 includes a first smoothing capacitor 31. A high-potential side path 32H is connected to a high-potential side terminal of the first smoothing capacitor 31. A low-potential side path 32L is connected to a low-potential side terminal of the first smoothing capacitor 31. The first smoothing capacitor 31 may be provided outside the first inverter 30.

[0023] A high potential side path 32H is connected to the collector, which is the high potential side terminal of the first upper arm switch SAH, and a low potential side path 32L is connected to the emitter, which is the low potential side terminal of the first lower arm switch SAL.

[0024] The first motor 40 is a three-phase synchronous machine and includes star-connected U-, V-, and W-phase first armature windings 41 and a first rotor 42. The first armature windings 41 of each phase are arranged at an electrical angle of 120°. The first motor 40 is, for example, a permanent magnet synchronous machine. The first rotor 42 is capable of transmitting power to the front wheels 12F of the vehicle 10.

[0025] First ends of the U-, V-, and W-phase first armature windings 41U, 41V, and 41W are connected to a connection point between the emitter of the first upper arm switch SAH and the collector of the first lower arm switch SAL via a first conductive member 33 such as a bus bar. Second ends of the U-, V-, and W-phase first armature windings 41U, 41V, and 41W are connected to each other at a first neutral point OA. In this embodiment, the U-, V-, and W-phase first armature windings 41U, 41V, and 41W are set to have the same number of turns. As a result, the U-, V-, and W-phase first armature windings 41U, 41V, and 41W are set to have the same inductance, for example.

[0026] The second inverter 50 includes three phases of series-connected upper and lower arm switches. Specifically, the second inverter 50 includes three-phase second upper arm switches SBH and three-phase second lower arm switches SBL. A second upper arm diode DBH, which is a freewheeling diode, is connected in antiparallel to the second upper arm switch SBH, and a second lower arm diode DBL, which is also a freewheeling diode, is connected in antiparallel to the second lower arm switch SBL. In this embodiment, each of the switches SBH and SBL is an IGBT.

[0027] The second inverter 50 includes a second smoothing capacitor 51. A high-potential side terminal of the second smoothing capacitor 51 is connected to the high-potential side path 32H. A low-potential side terminal of the second smoothing capacitor 51 is connected to the low-potential side path 32L. The second smoothing capacitor 51 may be provided outside the second inverter 50. Alternatively, instead of providing the second smoothing capacitor 51 individually for the second inverter 50 and the first smoothing capacitor 31 individually for the first inverter 30, a common capacitor may be provided for the first inverter 30 and the second inverter 50. In this case, for example, the second smoothing capacitor 51 may not be provided.

[0028] The second motor 60 is a three-phase synchronous machine and includes star-connected U-, V-, and W-phase second armature windings 61 and a second rotor 62. The second armature windings 61 for each phase are arranged with an electrical angle offset of 120°. The second motor 60 is, for example, a permanent magnet synchronous machine. The second rotor 62 is capable of transmitting power to the rear wheels 12R of the vehicle 10.

[0029] First ends of U-, V-, and W-phase second armature windings 61U, 61V, and 61W are connected to a connection point between the emitter of the second upper arm switch SBH and the collector of the second lower arm switch SBL via a second conductive member 53 such as a bus bar. Second ends of the U-, V-, and W-phase second armature windings 61U, 61V, and 61W are connected to each other at a second neutral point OB. In this embodiment, the U-, V-, and W-phase second armature windings 61U, 61V, and 61W are set to have the same number of turns. As a result, the U-, V-, and W-phase second armature windings 61U, 61V, and 61W are set to have the same inductance, for example.

[0030] The control system 20 includes a first switch 71, a second switch 72, and a connection path 73 as components for switching the connection state of the first storage battery 21 and the second storage battery 22. In this embodiment, each of the switches 71 and 72 is a mechanical relay. When turned off, each of the switches 71 and 72 blocks bidirectional current flow, and when turned on, each of the switches 71 and 72 allows bidirectional current flow. Each of the switches 71 and 72 is not limited to a mechanical relay, and may be, for example, a semiconductor switching element.

[0031] The connection path 73 is an electrical path connecting the intermediate terminal B and the first neutral point OA. The intermediate terminal B is on a path connecting the negative terminal of the first storage battery 21 and the positive terminal of the second storage battery 22. The connection path 73 is provided with a second switch 72 and a first switch 71 in this order from the first neutral point OA.

[0032] The control system 20 includes a neutral point capacitor 74 that connects the connection path 73 and the low potential side path 32L. A first end of the neutral point capacitor 74 is connected to a portion of the connection path 73 between the first switch 71 and the second switch 72. A second end of the neutral point capacitor 74 is connected to a portion of the low potential side path 32L between the second storage battery 22 and the first inverter 30.

[0033] When the first switch 71 is turned on, the first end of the neutral point capacitor 74 is electrically connected to the positive terminal of the second storage battery 22. On the other hand, when the first switch 71 is turned off, the first end of the neutral point capacitor 74 is electrically disconnected from the positive terminal of the second storage battery 22. When the second switch 72 is turned on, the first neutral point OA of the first armature winding 41 is electrically connected to the first end of the neutral point capacitor 74. On the other hand, when the second switch 72 is turned off, the first neutral point OA is electrically disconnected from the first end of the neutral point capacitor 74.

[0034] The collector of the second upper arm switch SBH is connected to the high potential side path 32H. The collector of the second upper arm switch SBH is connected to a portion of the high potential side path 32H between the first storage battery 21 and the first inverter 30. The emitter of the second lower arm switch SBL is connected to the low potential side path 32L. The emitter of the second lower arm switch SBL is connected to a portion of the low potential side path 32L between the second storage battery 22 and the first inverter 30.

[0035] The control system 20 includes current sensors for detecting currents flowing through various components thereof, including a first current sensor 81A, a second current sensor 81B, a first-phase current sensor 82, a second-phase current sensor 90, and a motor current sensor 83. The first current sensor 81A detects currents flowing through the first storage battery 21, and the second current sensor 81B detects currents flowing through the second storage battery 22. The first-phase current sensor 82 detects currents flowing through the U-, V-, and W-phase first armature windings 41U, 41V, and 41W. The second-phase current sensor 90 detects currents flowing through the U-, V-, and W-phase second armature windings 61U, 61V, and 61W. The motor current sensor 83 detects currents flowing through the connection path 73, and in this embodiment, detects currents flowing through a portion of the connection path 73 closer to the first neutral point OA than the connection point with the neutral point capacitor 74.

[0036] The control system 20 includes a capacitor voltage sensor 84 that detects the voltage across the neutral point capacitor 74, a first voltage sensor 85A that detects the voltage across the terminals of the first storage battery 21, and a second voltage sensor 85B that detects the voltage across the terminals of the second storage battery 22. The control system 20 also includes a power supply voltage sensor 86 that detects the voltage across the terminals of the first smoothing capacitor 31 (hereinafter referred to as the first smoothing capacitor voltage Vdc).

[0037] The control system 20 includes a first rotation angle sensor 87 that detects the rotation angle (electrical angle) of the first rotor 42, and a second rotation angle sensor 91 that detects the rotation angle (electrical angle) of the second rotor 62. The control system 20 also includes a first temperature sensor 88A that detects the temperature of the first storage battery 21, and a second temperature sensor 88B that detects the temperature of the second storage battery 22.

[0038] The control system 20 includes a battery ECU 100 that controls the first and second storage batteries 21, 22, a motor ECU 110 that controls the first and second inverters 30, 50, and an EVECU 120 that manages the system. The battery ECU 100 is an electronic control unit (ECU) that includes a processor 101 and a storage unit 102 as hardware components. The motor ECU 110 is an ECU that includes a processor 111 and a storage unit 112 as hardware components. The EVECU 120 is an ECU that includes a processor 121 and a storage unit 122 as hardware components. The EVECU 120 is a higher-level control unit than the battery ECU 100 and the motor ECU 110. The battery ECU 100 and the motor ECU 110 can exchange information via the EVECU 120.

[0039] The memory units 102, 112, and 122 include hardware memory and storage. The memory is a storage device for storing data used in the processing of the battery ECU 100, the motor ECU 110, or the EVECU 120. The memory provides the processors 101, 111, and 121 with a working area for temporary use when the processors 101, 111, and 121 perform processing, for example. The memory includes, for example, a ROM or a RAM. The storage is a storage device for storing various programs and data to be read and executed by the processors 101, 111, and 121, and is a non-transitory tangible storage medium. The storage includes, for example, a HDD or flash memory. The storage stores program information and the like for processing, such as those shown in FIGS. 9, 12, 14, 18, and 19, which will be described later.

[0040] For example, program information stored on a non-transient physical recording medium is installed in the storage units 102, 112, and 122. The recording medium is, for example, a USB memory, a CD-ROM, or a DVD. Also, for example, program information transmitted via a communication network, such as over the air (OTA), is installed in the storage units 102, 112, and 122.

[0041] The battery ECU 100 receives the detected values ​​of the first and second current sensors 81A and 81B, the first and second voltage sensors 85A and 85B, and the first and second temperature sensors 88A and 88B. The motor ECU 110 receives the detected value of the coolant temperature sensor. The motor ECU 110 also receives the detected values ​​of the first and second phase current sensors 82 and 90, the motor current sensor 83, the capacitor voltage sensor 84, the power supply voltage sensor 86, and the first and second rotation angle sensors 87 and 91.

[0042] The first and second switches 71, 72 may be controlled by any one of the battery ECU 100, the motor ECU 110, and the EVECU 120, or may be controlled by an ECU other than the ECUs 100, 110, and 120. In the present embodiment, the first and second switches 71, 72 are hereinafter assumed to be controlled by the motor ECU 110.

[0043] 2 may be controlled by any one of the battery ECU 100, the motor ECU 110, and the EVECU 120, or may be controlled by an ECU other than the ECUs 100, 110, and 120. In the present embodiment, the water pump 201 and the fan 203 are hereinafter assumed to be driven by the EVECU 120.

[0044] Next, the temperature-raising / driving control in which the temperature-raising control and the driving control are executed will be described. In this embodiment, the temperature-raising control raises the temperature of the first and second storage batteries 21, 22 (corresponding to the "temperature-raising target parts"). Furthermore, the driving control rotates at least one of the first rotor 42 and the second rotor 62.

[0045] FIG. 4 is a block diagram showing the control process of the control system 20 executed by the motor ECU 110. As shown in FIG.

[0046] The motor ECU 110 includes a temperature rise determination unit 130 , a drive determination unit 131 , and a switch control unit 132 .

[0047] The temperature rise determination unit 130 determines whether there is a temperature rise request for the first storage battery 21 and the second storage battery 22. For example, the temperature rise determination unit 130 determines that there is a temperature rise request when it determines that the temperature rise target temperature Tr is equal to or lower than the target temperature T*. Here, the temperature rise target temperature Tr is, for example, the lower of the temperatures of the first storage battery 21 and the second storage battery 22, or the average temperature of the first storage battery 21 and the second storage battery 22. The temperature of the first storage battery 21 used in the temperature rise determination unit 130 is, for example, the value detected by the first temperature sensor 88A. The temperature of the second storage battery 22 used in the temperature rise determination unit 130 is, for example, the value detected by the second temperature sensor 88B. The temperature rise determination unit 130 inputs the determination result to the switch control unit 132.

[0048] The drive determination unit 131 determines whether there is a drive request to run the vehicle 10 by rotationally driving at least one of the first rotor 42 and the second rotor 62. The drive determination unit 131 determines whether there is a drive request based on, for example, an upper command torque Trqt*. Here, the upper command torque Trqt* is, for example, a command torque input from the EVECU 120 to the motor ECU 110. The drive determination unit 131 inputs the determination result to the switch control unit 132.

[0049] The determination results of the temperature rise determination unit 130 and the drive determination unit 131, and the higher-level command torque Trqt* are input to the switch control unit 132. When the switch control unit 132 determines that a temperature rise request and a drive request have been made, it turns on the first and second switches 71, 72 and executes the temperature rise / drive control.

[0050] When executing the temperature increase / drive control, the switch control unit 132 calculates a first command torque Trq1* and a second command torque Trq2* based on the higher-level command torque Trqt*. The first command torque Trq1* is the command torque for the first motor 40, and the second command torque Trq2* is the command torque for the second motor 60.

[0051] The switch control unit 132 distributes the higher-level command torque Trqt* to a first command torque Trq1* and a second command torque Trq2*. Specifically, the switch control unit 132 distributes, for example, a portion of the higher-level command torque Trqt* to the first command torque Trq1*. The switch control unit 132 calculates the second command torque Trq2* by subtracting the first command torque Trq1* from the higher-level command torque Trqt*.

[0052] In this embodiment, the switch control unit 132 executes temperature rise control to raise the temperatures of the first and second storage batteries 21, 22 using the first power conversion unit 301. Fig. 5 shows an equivalent circuit of the first and second storage batteries 21, 22, the first inverter 30, and the first motor 40 used in the temperature rise control. In Fig. 5, the first armature windings 41U, 41V, 41W of each phase are shown as first armature windings 41.

[0053] The equivalent circuit of Figure 5 can be shown as the equivalent circuit of Figure 6. The circuit of Figure 6 is a buck-boost chopper circuit capable of bidirectional power transmission between the first storage battery 21 and the second storage battery 22. In Figure 6, IBH represents the current flowing through the first storage battery 21, VBH represents the terminal voltage of the first storage battery 21, IBL represents the current flowing through the second storage battery 22, and VBL represents the terminal voltage of the second storage battery 22. IBH and IBL are negative when charging currents flow through the first and second storage batteries 21 and 22, and positive when discharging currents flow through the first and second storage batteries 21 and 22. VR represents the terminal voltage of the first armature winding 41, and IMr represents the current flowing through the first neutral point OA. The neutral point current IMr is considered positive when it flows from the first armature winding 41 through the connection path 73 toward the intermediate terminal B, and negative when it flows from the intermediate terminal B toward the first armature winding 41 through the connection path 73.

[0054] 6, when the first upper-arm switch SAH is turned on, the voltage VR across the terminals of the first armature winding 41 becomes "VBH." On the other hand, when the first lower-arm switch SAL is turned on, the voltage VR across the terminals of the first armature winding 41 becomes "-VBL." In other words, when the first upper-arm switch SAH is turned on, an excitation current can be made to flow through the first armature winding 41 in the positive direction of the neutral point current IMr, and when the first lower-arm switch SAL is turned on, an excitation current can be made to flow through the first armature winding 41 in the negative direction of the neutral point current IMr.

[0055] Hereinafter, a method will be described in which the switch control unit 132 controls the torque of the first motor 40 to the first command torque Trq1* while raising the temperatures of the first and second storage batteries 21, 22 using the first power conversion unit 301.

[0056] 7 is a block diagram of the temperature increase / drive control process executed by the switch control unit 132. The switch control unit 132 includes a d, q-axis command current setting unit 140, d, q-axis deviation calculation units 141d, 141q, d, q-axis control units 142d, 142q, and a three-phase conversion unit 143.

[0057] The d- and q-axis command current setting unit 140 sets a d-axis command current Id* and a q-axis command current Iq* based on the first command torque Trq1* and inputs them to a d-axis deviation calculation unit 141d and a q-axis deviation calculation unit 141q. The d-axis deviation calculation unit 141d calculates a d-axis current deviation ΔId by subtracting the d-axis current Idr from the d-axis command current Id* and inputs it to a d-axis control unit 142d. The q-axis deviation calculation unit 141q calculates a q-axis current deviation ΔIq by subtracting the q-axis current Iqr from the q-axis command current Iq* and inputs it to a q-axis control unit 142q. The d-axis current Idr and the q-axis current Iqr are calculated based on the detection value of the first-phase current sensor 82 and the electrical angle of the first motor 40. The electrical angle may be a detection value of the first rotation angle sensor 87 or an estimated value estimated using position sensorless control.

[0058] The d-axis control unit 142d calculates a d-axis voltage Vd as an operation amount for feedback-controlling the d-axis current deviation ΔId calculated by the d-axis deviation calculation unit 141d to zero, and inputs the calculated voltage to the three-phase conversion unit 143. The q-axis control unit 142q calculates a q-axis voltage Vq as an operation amount for feedback-controlling the q-axis current deviation ΔIq calculated by the q-axis deviation calculation unit 141q to zero, and inputs the calculated voltage to the three-phase conversion unit 143. In this embodiment, proportional-integral control is used as the feedback control of each of the control units 142d, 142q. Note that the feedback control is not limited to proportional-integral control, and may be, for example, proportional-integral-derivative control.

[0059] The three-phase converter 143 calculates U-, V-, and W-phase command voltages Vu, Vv, and Vw in a three-phase fixed coordinate system based on the d-axis voltage Vd, the q-axis voltage Vq, and the electrical angle. When it is determined that a drive request exists, the U-, V-, and W-phase command voltages Vu, Vv, and Vw are sinusoidal signals with the same amplitude but shifted in phase by 120 electrical degrees.

[0060] The switch control unit 132 includes a temperature rise control unit 150. The temperature rise control unit 150 includes a command value setting unit 151, a neutral point deviation calculation unit 152, a neutral point control unit 153, and U, V, and W phase superimposition units 154U, 154V, and 154W.

[0061] The command value setting unit 151 sets the neutral point command current IM* and inputs it to the neutral point deviation calculation unit 152. In this embodiment, the waveform of the neutral point command current IM* is set as a sine wave, as shown in FIG. 8 . Specifically, the neutral point command current IM* has an amplitude Ia and a period Tc. The neutral point command current IM* is set so that the positive and negative neutral point command currents IM* are point-symmetric with respect to the timing at which the value of the neutral point command current IM* changes from a non-zero value to zero (hereinafter referred to as the zero-crossing timing). As a result, in FIG. 8 , the period from the first zero-crossing timing C1 to the second zero-crossing timing C2 of the neutral point command current IM* is equal to the period from the second zero-crossing timing C2 to the third zero-crossing timing C3.

[0062] In addition, in one cycle Tc of the neutral point command current IM*, the area S1 of the first region and the area S2 of the second region are equal. The area S1 of the first region is the region surrounded by the positive neutral point command current IM* and the time axis from the first zero-cross timing C1 to the second zero-cross timing C2 of the neutral point command current IM* in one cycle Tc of the neutral point command current IM*. The area S2 of the second region is the region surrounded by the negative neutral point command current IM* and the time axis from the second zero-cross timing C2 to the third zero-cross timing C3 of the neutral point command current IM* in one cycle Tc.

[0063] By setting the area S1 of the first region and the area S2 of the second region to be equal, it is possible to balance the charge / discharge currents of the first storage battery 21 and the second storage battery 22 in one cycle Tc. Therefore, it is possible to prevent the difference between the terminal voltage VBH of the first storage battery 21 and the terminal voltage VBL of the second storage battery 22 from increasing due to the temperature rise control.

[0064] Returning to the explanation of Figure 7, the neutral point deviation calculation unit 152 calculates the neutral point current deviation ΔIM by subtracting the neutral point current IMr, which is the current detected by the motor current sensor 83, from the neutral point command current IM*, and inputs it to the neutral point control unit 153.

[0065] The neutral point control unit 153 calculates an offset correction amount CF as a manipulated variable for feedback-controlling the calculated neutral point current deviation ΔIM to zero, and inputs the calculated offset correction amount CF to the U-, V-, and W-phase superimposing units 154U, 154V, and 154W. In this embodiment, proportional-integral control is used as this feedback control. Note that the feedback control is not limited to proportional-integral control, and may be, for example, proportional-integral-derivative control.

[0066] The U-phase superimposing unit 154U calculates a U-phase final command voltage "Vu+CF" by adding an offset correction amount CF to the U-phase command voltage Vu input from the three-phase conversion unit 143. The V-phase superimposing unit 154V calculates a V-phase final command voltage "Vv+CF" by adding an offset correction amount CF to the V-phase command voltage Vv input from the three-phase conversion unit 143. The W-phase superimposing unit 154W calculates a W-phase final command voltage "Vw+CF" by adding an offset correction amount CF to the W-phase command voltage Vw input from the three-phase conversion unit 143.

[0067] The switch control unit 132 includes U-, V-, and W-phase modulation units 155U, 155V, and 155W. The U-phase modulation unit 155U calculates a U-phase modulation factor Mu by dividing the U-phase final command voltage input from the U-phase superimposing unit 154U by the first smoothing capacitor voltage Vdc. The V-phase modulation unit 155V calculates a V-phase modulation factor Mv by dividing the V-phase final command voltage input from the V-phase superimposing unit 154V by the first smoothing capacitor voltage Vdc. The W-phase modulation unit 155W calculates a W-phase modulation factor Mw by dividing the W-phase final command voltage input from the W-phase superimposing unit 154W by the first smoothing capacitor voltage Vdc.

[0068] 4, the switch control unit 132 inputs switching signals to the first upper and lower arm switches SAH, SAL to control the switching of the switches SAH, SAL based on the calculated modulation factors Mu, Mv, Mw. Specifically, for example, the motor ECU 110 may perform switching control using PWM control based on a magnitude comparison between the modulation factors Mu, Mv, Mw and a carrier signal (e.g., a triangular wave signal).

[0069] Furthermore, the switch control unit 132 inputs switching signals to the second upper and lower arm switches SBH and SBL to control the torque of the second motor 60 to the second command torque Trq2*.

[0070] 9 is a flowchart showing the procedure of the temperature increase / drive control process, which is repeatedly executed by the motor ECU 110 at a predetermined control interval, for example.

[0071] In step S10, the temperature increase determination unit 130 determines whether there is a temperature increase request for the first and second storage batteries 21, 22. If it is determined in step S10 that there is a temperature increase request, the process proceeds to step S11. In step S11, the switch control unit 132 calculates, for example, a neutral point command current IM*, which is a command value for the neutral point current IMr required to set the temperature increase target temperature Tr to the target temperature T*.

[0072] In step S12, the higher-level command torque Trqt* is acquired. In step S13, the drive determination unit 131 determines whether or not there is a drive request.

[0073] If it is determined in step S13 that there is a drive request, the process proceeds to step S14, in which the switch control unit 132 calculates a first command torque Trq1*, and in step S15, the second command torque Trq2* is calculated.

[0074] In step S16, the switch control unit 132 controls the switching of the first upper and lower arm switches SAH and SAL to control the torque of the first motor 40 to the first command torque Trq1* while raising the temperatures of the first and second storage batteries 21 and 22 using the first power conversion unit 301. Also, it controls the switching of the second upper and lower arm switches SBH and SBL to control the torque of the second motor 60 to the second command torque Trq2*.

[0075] If it is determined that there is no temperature increase request, but there is a drive request, a drive control process different from that shown in FIG. 9 is executed to run the vehicle 10.

[0076] When the first and second switches 71 and 72 are turned off, the first neutral point OA is not connected to the intermediate terminal B via the connection path 73. In this case, when switching control is executed to cause the first motor 40 to generate torque, the maximum value of the inter-terminal voltage of the first armature windings 41U, 41V, and 41W of the U-, V-, and W-phases is two-thirds of the power supply voltage Vbat, which is the voltage between the high-potential side path 32H and the low-potential side path 32L. When executing the temperature-rise / drive control, the motor ECU 110 turns on the first and second switches 71 and 72 to execute the temperature-rise control, and connects the first neutral point OA to the intermediate terminal B via the connection path 73. In this case, when switching control is executed to cause the first motor 40 to generate torque, the maximum value of the inter-terminal voltage of the first armature windings 41U, 41V, and 41W of the U-, V-, and W-phases is one-half of the power supply voltage Vbat.

[0077] For this reason, when the temperature rise / drive control is executed, the range in which the operating point of the first motor 40 can be set is smaller than when the temperature rise control is not executed, raising the concern that the output torque of the first motor 40 may not be set to the first command torque Trq1*. Therefore, in the temperature rise / drive control of this embodiment, the higher-level command torque Trqt* is distributed to the first command torque Trq1* and the second command torque Trq2*. This prevents the output torque of the first motor 40 from being set to the first command torque Trq1* when the temperature rise control and the drive control are executed. This reduces the effect of executing the temperature rise control on the total output torque of the first and second motors 40, 60.

[0078] <Modification of First Embodiment> In the temperature increase / drive control, the switch control unit 132 does not have to rotate the first rotor 42. In this case, for example, the switch control unit 132 may set the first command torque Trq1* to 0 and the second command torque Trq2* to the higher-order command torque Trqt*.

[0079] Second Embodiment A second embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, the first motor 40 is a wound field motor as shown in Fig. 10. Note that in Fig. 10, the same components as those shown in Fig. 3 are denoted by the same reference numerals for convenience.

[0080] In this embodiment, the first rotor 42 includes a field winding 210. The first rotor 42 includes a rotor core and a plurality of field salient poles extending radially from the rotor core. The field winding 210 is wound around each of the field salient poles.

[0081] The control system 20 includes a field energization circuit 211. The field energization circuit 211 supplies current from the first and second storage batteries 21, 22 to the field winding 210. As shown in Fig. 11 , the field energization circuit 211 of this embodiment is a full-bridge circuit that includes a series connection of a third upper arm switch SAHf and a third lower arm switch SALf, and a series connection of a fourth upper arm switch SBHf and a fourth lower arm switch SBLf. In this embodiment, the switches SAHf, SALf, SBHf, and SBLf are IGBTs.

[0082] The third and fourth upper-arm switches SAHf and SBHf are connected in anti-parallel to third and fourth upper-arm diodes DAHf and DBHf, which are freewheel diodes, and the third and fourth lower-arm switches SALf and SBLf are connected in anti-parallel to third and fourth lower-arm diodes DALf and DBLf, which are freewheel diodes.

[0083] The collectors of the third and fourth upper arm switches SAHf, SBHf are connected to the positive terminal of the first storage battery 21 via a high potential side path 32H. The emitters of the third and fourth lower arm switches SALf, SBLf are connected to the negative terminal of the second storage battery 22 via a low potential side path 32L. A first end of the field winding 210 is connected to the connection point between the third upper arm switch SAHf and the third lower arm switch SALf via a brush (not shown). A second end of the field winding 210 is connected to the connection point between the fourth upper arm switch SBHf and the fourth lower arm switch SBLf via a brush (not shown).

[0084] The field energization circuit 211 includes a third smoothing capacitor 212, which is a smoothing capacitor. The third smoothing capacitor 212 may be provided outside the field energization circuit 211. Furthermore, instead of the configuration in which the third smoothing capacitor 212 is provided individually in the field energization circuit 211 and the first smoothing capacitor 31 is provided individually in the first inverter 30, a configuration in which a common capacitor is provided to the first inverter 30 and the field energization circuit 211 may be adopted. In this case, for example, the third smoothing capacitor 212 may not be provided.

[0085] 10 , the control system 20 includes a field current sensor 92. The field current sensor 92 detects the field current flowing through the field winding 210. The detected value of the field current sensor 92 is input to the motor ECU 110.

[0086] In drive control, the motor ECU 110 performs switching control of the upper and lower arm switches constituting the field energization circuit 211 to excite the field winding 210. More specifically, the motor ECU 110 performs switching control so that a first state and a second state alternate, in order to control the field current Ifr detected by the field current sensor 92 to the field target current If*. The first state is a state in which the third upper arm switch SAHf and the fourth lower arm switch SBLf are turned on, and the fourth upper arm switch SBHf and the third lower arm switch SALf are turned off. The second state is a state in which the third upper arm switch SAHf and the fourth lower arm switch SBLf are turned off, and the fourth upper arm switch SBHf and the third lower arm switch SALf are turned on.

[0087] 12 is a flowchart showing the procedure of the temperature increase / drive control process in this embodiment. This process is repeatedly executed by the motor ECU 110 at a predetermined control interval, for example.

[0088] After step S15 is executed, in step S20, the supply of current from the first and second storage batteries 21, 22 to the field winding 210 is stopped. Specifically, the motor ECU 110 sets the field target current If* to 0, for example, and turns off the third and fourth upper arm switches SAHf, SBHf and the third and fourth lower arm switches SALf, SBLf. After step S20 is executed, step S16 is executed.

[0089] If a permanent magnet motor is used as the first motor 40, when the temperature rise / drive control is executed, the neutral point current may decrease relative to the neutral point command current IM* due to the back electromotive force generated in the first motor 40. In this case, the efficiency of the temperature rise control may decrease. For this reason, in this embodiment, a field winding type motor is used as the first motor 40. When executing the temperature rise / drive control, the motor ECU 110 controls the field energization circuit 211 so that no current flows through the field winding 210. This prevents the back electromotive force from occurring, and the neutral point current can be controlled to the neutral point command current IM*. As a result, a decrease in the efficiency of the temperature rise control can be suppressed.

[0090] In this embodiment, the motor ECU 110 may set the first command torque Trq1* to 0 when no current flows through the field winding 210. In this case, after steps S10 to S13 are executed in Fig. 12, the first command torque Trq1* is set to 0 in step S14, and the second command torque Trq2* is set to the higher-order command torque Trqt* in step S15.

[0091] According to the present embodiment described above, it is possible to suppress a decrease in the efficiency of the temperature rise control while reducing the effect that the execution of the temperature rise control has on the total output torque of the first and second motors 40, 60.

[0092] Third Embodiment A third embodiment will now be described with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, as shown in Fig. 13, the vehicle 10 includes a power transmission mechanism 220. Note that in Fig. 13, the same components as those shown in Fig. 3 are denoted by the same reference numerals for convenience.

[0093] The rotary shaft of the first rotor 42 and the axle of the front wheel 12F are connected via a power transmission mechanism 220. Specifically, the power transmission mechanism 220 includes at least one of a clutch and a transmission. The clutch switches between connection and disconnection between the input shaft and the output shaft of the clutch, and adjusts the degree of torque transmitted from the first rotor 42 to the axle of the front wheel 12F. The clutch is, for example, a hydraulically driven wet clutch. The transmission adjusts the gear ratio, which is the ratio between the rotational speed of the input shaft of the transmission and the rotational speed of the output shaft of the transmission. The transmission is, for example, a continuously variable transmission (CVT) or a stepped transmission. In this embodiment, the power transmission mechanism 220 is controlled by the EVECU 120.

[0094] 14 is a flowchart showing the procedure of the temperature increase / drive control process in this embodiment. This process is repeatedly executed by the motor ECU 110 at a predetermined control interval, for example.

[0095] In step S30, a disconnection command is input to the EVECU 120 to disconnect the rotary shaft of the first rotor 42 from the axle of the front wheels 12F. When the disconnection command is input, the EVECU 120 controls, for example, a clutch to disconnect the rotary shaft of the first rotor 42 from the axle of the front wheels 12F. When the disconnection command is input, the EVECU 120 may control the transmission to place the gears constituting the transmission in neutral.

[0096] After step S30 is executed, step S16 is executed.

[0097] When executing the temperature increase / drive control, the motor ECU 110 disconnects the rotary shaft of the first rotor 42 from the axle of the front wheels 12F. This prevents the rotational force of the wheels from being transmitted to the first rotor 42, even when the wheels are rotating to propel the vehicle 10, thereby reducing the back electromotive force. As a result, the neutral point current can be controlled to the neutral point command current IM*, and a decrease in the efficiency of the temperature increase control can be suppressed.

[0098] In this embodiment, because the rotation shaft of the first rotor 42 is disconnected from the axle of the front wheels 12F, the first command torque Trq1* may be set to 0. In this case, after steps S10 to S13 are executed in Fig. 14, the first command torque Trq1* is set to 0 in step S14, and the second command torque Trq2* is set to the higher-order command torque Trqt* in step S15.

[0099] According to the present embodiment described above, it is possible to suppress a decrease in the efficiency of the temperature rise control while reducing the effect that the execution of the temperature rise control has on the total output torque of the first and second motors 40, 60.

[0100] Fourth Embodiment A fourth embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, the motor ECU 110 increases the temperatures of the first and second storage batteries 21, 22 by inefficiently driving either the first power conversion unit 301 or the second power conversion unit 302 during the temperature increase / drive control.

[0101] As shown in FIG. 15, in comparison with the first embodiment, the control system 20 in this embodiment does not include the connection path 73 and the first and second switches 71 and 72 .

[0102] FIG. 16 is a block diagram showing the control process of the control system 20 executed by the motor ECU 110.

[0103] The motor ECU 110 includes a temperature rise determination unit 130 , a drive determination unit 131 , a switch control unit 132 , and a selection unit 133 .

[0104] The selection unit 133 receives the determination result by the temperature increase determination unit 130 as to whether or not there is a temperature increase request, and the target temperature Tr for temperature increase of the first and second storage batteries 21, 22. When the determination result indicating that there is a temperature increase request is input, the selection unit 133 selects the power conversion unit to be increased in temperature from the first power conversion unit 301 or the second power conversion unit 302. The selection unit 133 inputs the selection result to the switch control unit 132.

[0105] When executing the temperature increase / drive control, the switch control unit 132 performs temperature increase control that drives the first inverter 30 or the second inverter 50 inefficiently in order to increase the temperature of the power conversion unit selected by the selection unit 133.

[0106] A first example of inefficient driving will be described. When executing temperature increase control to increase the temperature of the first power conversion unit 301, the switch control unit 132 reduces the gate-emitter voltage of the upper and lower arm switches constituting the first inverter 30 when turning on the switches. This increases the on-resistance, causing the temperature of the first power conversion unit 301 to increase.

[0107] A second example of inefficient driving will be described. The switch control unit 132 increases the magnitude of the current vector of the first armature winding 41 while controlling the torque of the first motor 40 to the first command torque Trq1*.

[0108] FIG. 17 shows current operating points of the first motor 40 determined from the d- and q-axis currents Idr and Iqr during drive control and temperature rise / drive control. The horizontal axis of FIG. 17 represents the d-axis current Idr, and the vertical axis represents the q-axis current Iqr. Ltc represents an equal torque line formed by a combination of the d- and q-axis currents Idr and Iqr when the torque is the same. The equal torque line is determined based on the first command torque Trq1*. Lmtpa represents a maximum efficiency line formed by a combination of the d- and q-axis currents Idr and Iqr corresponding to minimum current maximum torque control (MTPA).

[0109] The current operating point in the drive control is controlled to lie on, for example, the maximum efficiency line Lmtpa. Specifically, in the drive control, the current operating point is the first operating point OP1, and the current vector of the first armature winding 41 is the first current vector Vt1. On the other hand, in the temperature increase / drive control, the current operating point is controlled to lie on the constant torque line Ltc, and the magnitude of the current vector of the first armature winding 41 is controlled to be greater than the magnitude of the first current vector Vt1. For example, the current operating point in the temperature increase / drive control is the second operating point OP2. In this case, the current vector of the first armature winding 41 is the second current vector Vt2, and the magnitude of the second current vector Vt2 is greater than the magnitude of the first current vector Vt1. As a result, the switch control unit 132 can increase the temperature of the first power conversion unit 301 while suppressing fluctuations in the output torque of the first motor 40.

[0110] When performing temperature increase control to increase the temperature of the second power conversion unit 302, the switch control unit 132, for example, reduces the gate-to-emitter voltage of the upper and lower arm switches constituting the second inverter 50 when turning on the switches. This increases the on-resistance and increases the temperature of the second power conversion unit 302. Furthermore, for example, the switch control unit 132 increases the magnitude of the current vector of the second armature winding 61 while controlling the torque of the second motor 60 to the second command torque Trq2*, in the same manner as when increasing the temperature of the first power conversion unit 301. In this way, the switch control unit 132 can increase the temperature of the second power conversion unit 302 while suppressing fluctuations in the output torque of the second motor 60.

[0111] 18 is a flowchart showing the procedure of the temperature increase / drive control process in this embodiment. This process is repeatedly executed by the motor ECU 110 at a predetermined control interval, for example.

[0112] After execution of step S10, in step S40, the selector 133 selects the power conversion unit to be heated from the first power conversion unit 301 or the second power conversion unit 302. In the following, for convenience, it is assumed that the first power conversion unit 301 is selected.

[0113] After steps S12 to S15 are executed, step S16 is executed. In step S16, the switch control unit 132 controls the switching of the first upper and lower arm switches SAH and SAL to control the torque of the first motor 40 to the first command torque Trq1* while raising the temperature of the first power conversion unit 301. Also, it controls the switching of the second upper and lower arm switches SBH and SBL to control the torque of the second motor 60 to the second command torque Trq2*.

[0114] The heat of the first power conversion unit 301 is transferred to the first and second storage batteries 21, 22 via the coolant circulating through the circulation path 200 by driving the water pump 201 shown in FIG. 2. The temperature increase / drive control is continued, for example, until the target temperature Tr of the first and second storage batteries 21, 22 reaches the target temperature T*. The drive of the water pump 201 is continued at least while the temperature increase / drive control is being executed.

[0115] When repeatedly executing the process shown in FIG. 18, the motor ECU 110 may switch the power conversion unit selected in step S40 between the first power conversion unit 301 and the second power conversion unit 302 every specified period.

[0116] During the temperature-raising / driving control, the motor ECU 110 inefficiently drives the first power conversion unit 301 or the second power conversion unit 302 using the above-described method so as not to affect the output torque of the first and second motors 40 and 60. This raises the temperature of the first power conversion unit 301 or the second power conversion unit 302. Heat generated by the temperature-raising control is transferred to the first and second storage batteries 21 and 22 via the coolant circulating through the circulation path 200, raising the temperature of the first and second storage batteries 21 and 22. Here, there is a concern that components constituting the power conversion units may overheat due to inefficient driving. Therefore, when repeating the temperature-raising / driving control, the motor ECU 110 switches the power conversion unit to be heated by inefficient driving. Specifically, for example, the motor ECU 110 switches between the first inverter 30 and the second inverter 50 as the inverter to be inefficiently driven at regular intervals. This allows one of the first inverter 30 that drives the front wheels 12F and the second inverter 50 that drives the rear wheels 12R to be used to heat up the first and second storage batteries 21, 22, and the other to be used to drive the vehicle 10.

[0117] According to the present embodiment described above, it is possible to reduce the effect that executing temperature rise control has on the total output torque of the first and second motors 40, 60, while preventing the components constituting the power conversion unit whose temperature is raised by the temperature rise control from becoming overheated.

[0118] Fifth Embodiment A fifth embodiment will be described below with reference to the drawings, focusing on differences from the fourth embodiment. In this embodiment, the motor ECU 110 selects the number of power conversion units to be inefficiently driven based on the target heat amount Ptgt* [W] to be generated per unit time.

[0119] 19 is a flowchart showing the procedure of the temperature increase / drive control process in this embodiment. This process is repeatedly executed by the motor ECU 110 at a predetermined control interval, for example.

[0120] After execution of step S10, in step S50, the selection unit 133 calculates the target heat quantity Ptgt*. For example, the selection unit 133 calculates the target heat quantity Ptgt* as follows. The selection unit 133 calculates the temperature difference ΔT (= T* - Tr) by subtracting the target temperature Tr to be heated from the target temperature T*. The larger the temperature difference ΔT, the larger the target heat quantity Ptgt* that the selection unit 133 calculates.

[0121] In step S51, the selection unit 133 determines whether the target heat amount Ptgt* is greater than the high heat threshold PthH (corresponding to the "second threshold"). If it is determined that the target heat amount Ptgt* is greater than the high heat threshold PthH, the process proceeds to step S52, where the first power conversion unit 301 and the second power conversion unit 302 are selected as the power conversion units whose temperatures are to be increased.

[0122] If it is determined that the target heat quantity Ptgt* is equal to or less than the high heat threshold PthH, the process proceeds to step S53. In step S53, the selection unit 133 determines whether the target heat quantity Ptgt* is greater than the low heat threshold PthL (corresponding to the "first threshold") and equal to or less than the high heat threshold PthH. Here, the low heat threshold PthL is a value smaller than the high heat threshold PthH.

[0123] If a negative determination is made in step S53, the power conversion unit to be heated is not selected, and the process proceeds to step S12.

[0124] If the determination in step S53 is affirmative, the process proceeds to step S54, where the first power conversion unit 301 or the second power conversion unit 302 is selected as the power conversion unit whose temperature is to be increased.

[0125] After steps S12 to S15 are executed, step S16 is executed. The process executed in step S16 will be described for different cases. First, a case where the first power conversion unit 301 and the second power conversion unit 302 are selected in step S52 will be described. In this case, in step S16, the switch control unit 132 controls the switching of the first upper and lower arm switches SAH and SAL to control the torque of the first motor 40 to the first command torque Trq1* while raising the temperature of the first power conversion unit 301. Furthermore, the switch control unit 132 controls the switching of the second upper and lower arm switches SBH and SBL to control the torque of the second motor 60 to the second command torque Trq2* while raising the temperature of the second power conversion unit 302.

[0126] Next, a case where the first power conversion unit 301 is selected in step S54 will be described. In this case, in step S16, the switch control unit 132 controls the switching of the first upper and lower arm switches SAH, SAL to control the torque of the first motor 40 to the first command torque Trq1* while raising the temperature of the first power conversion unit 301. Also, the switch control unit 132 controls the switching of the second upper and lower arm switches SBH, SBL to control the torque of the second motor 60 to the second command torque Trq2* without performing temperature rise control.

[0127] The motor ECU 110 selects the number of power conversion units to be heated based on the target heat amount Ptgt* calculated based on the difference between the target temperature T* and the target temperature Tr, thereby generating an appropriate amount of heat according to the difference between the target temperature T* and the target temperature Tr.

[0128] <Modification of Fifth Embodiment> The control system 20 shown in Fig. 15 may include the connection path 73 and the first and second switches 71, 72 shown in Fig. 3. The connection state of the connection path 73 and the first and second switches 71, 72 is the same as in the first embodiment. Changes to the control method in this case will be described below. When the motor ECU 110 executes step S52 in Fig. 19 or selects the first power conversion unit 301 in step S54, the motor ECU 110 may execute the temperature rise control described in the first embodiment in step S16.

[0129] Other Embodiments The above-described embodiments may be modified as follows.

[0130] Instead of the systems of the first to third embodiments, a control system 20 as shown in FIG. 20 may be used. The control system 20 includes a third switch 75. The third switch 75 connects the second neutral point OB and the connection path 73. The third switch 75 is a mechanical relay. When the third switch 75 is turned off, it blocks the flow of current in both directions, and when the third switch 75 is turned on, it allows the flow of current in both directions. The third switch 75 is not limited to a mechanical relay, and may be, for example, a semiconductor switching element.

[0131] 20 , when executing temperature increase / drive control, the motor ECU 110 turns on and off the second and third switches 72 and 75 so as not to connect the first neutral point OA and the second neutral point OB. Specifically, for example, when executing temperature increase control in the first power conversion unit 301, the motor ECU 110 turns on the second switch 72 and turns off the third switch 75. On the other hand, when executing temperature increase control in the second power conversion unit 302, the motor ECU 110 turns off the second switch 72 and turns on the third switch 75.

[0132] As shown in FIG. 21 , the control system 20 may include an inter-battery switch 76 and a bypass switch 77 as components for switching the connection state between the first storage battery 21 and the second storage battery 22 .

[0133] The inter-battery switch 76 and the bypass switch 77 are mechanical relays. When turned off, the inter-battery switch 76 and the bypass switch 77 block bidirectional current flow, and when turned on, they allow bidirectional current flow. Note that the inter-battery switch 76 and the bypass switch 77 are not limited to mechanical relays and may be, for example, semiconductor switching elements.

[0134] The inter-battery switch 76 connects the negative terminal of the first storage battery 21 and the positive terminal of the second storage battery 22. When the inter-battery switch 76 is turned on, the negative terminal of the first storage battery 21 and the positive terminal of the second storage battery 22 are electrically connected. When the inter-battery switch 76 is turned off, the negative terminal of the first storage battery 21 and the positive terminal of the second storage battery 22 are electrically disconnected.

[0135] The bypass switch 77 connects the negative terminal of the first storage battery 21 and the low potential side path 32L. When the bypass switch 77 is turned on, the negative terminal of the first storage battery 21 and the negative terminal of the second storage battery 22 are electrically connected. When the bypass switch 77 is turned off, the negative terminal of the first storage battery 21 and the negative terminal of the second storage battery 22 are electrically disconnected.

[0136] In the control system 20 shown in Fig. 21, when the temperature increase / drive control is executed, the inter-battery switch 76 is turned on and the bypass switch 77 is turned off. The control system 20 shown in Fig. 21 can also execute the temperature increase / drive control shown in the first to third embodiments.

[0137] In the first to third embodiments, either the first or second switch 71, 72 does not have to be included in the control system 20. Furthermore, both the first and second switches 71, 72 do not have to be included in the control system 20.

[0138] The method for setting the neutral point command current IM* is not limited to the method shown in Fig. 8. For example, the positive neutral point command current IM* and the negative neutral point command current IM* may be set to a trapezoidal wave or a rectangular wave, while satisfying a point-symmetric relationship between the positive neutral point command current IM* and the negative neutral point command current IM* with respect to the zero-cross timing of the neutral point command current IM* in one cycle Tc.

[0139] Furthermore, the method for setting the neutral point command current IM* is not limited to the point-symmetric relationship. For example, the neutral point command current IM* may be set so that, in one cycle Tc, the period from the first zero-cross timing C1 to the second zero-cross timing C2 of the neutral point command current IM* is different from the period from the second zero-cross timing C2 to the third zero-cross timing C3 of the neutral point command current IM*, and so that the area S1 of the first region and the area S2 of the second region are equal. Even in this case, the balance of the charge and discharge currents of the first storage battery 21 and the second storage battery 22 in one cycle Tc can be balanced.

[0140] The target to be heated by the temperature rise control may be, for example, the coolant in the circulation path 200. If the vehicle is equipped with an air conditioning system that uses the coolant as a heat source for heating the passenger compartment, the temperature of the heating heat source can be quickly raised by the temperature rise control. In this case, the motor ECU 110 may determine that a temperature rise request exists when, for example, it determines that the detected value Thw of the coolant temperature sensor is lower than the target temperature.

[0141] The heat transfer unit is not limited to a unit that uses cooling water as a cooling fluid, and may be, for example, an air-cooled unit that uses gas (air) as a cooling fluid, or a metal heat sink. When a heat sink is used as the heat transfer unit, for example, the first and second inverters 30, 50 and the first and second storage batteries 21, 22 may be provided on the heat sink.

[0142] 19, the temperature difference ΔT may be used instead of the target heat amount Ptgt*. In this case, the motor ECU 110 determines in step S51 whether the temperature difference ΔT is higher than a high temperature threshold value TthH (corresponding to the "second threshold value").

[0143] If the motor ECU 110 determines that the temperature difference ΔT is equal to or less than the high temperature threshold TthH, the process proceeds to step S53. In step S53, the motor ECU 110 determines whether the temperature difference ΔT is higher than the low temperature threshold TthL (corresponding to the "first threshold") and equal to or less than the high temperature threshold TthH. Here, the low temperature threshold TthL is a value lower than the high temperature threshold TthH.

[0144] The switches constituting the first and second inverters 30, 50 and the field energization circuit 211 are not limited to IGBTs and may be, for example, N-channel MOSFETs with body diodes. In this case, the high-potential terminal of the N-channel MOSFET serves as the drain, and the low-potential terminal serves as the source.

[0145] The motor is not limited to star-connected motors, but may be delta-connected. The motor and inverter are not limited to three-phase motors, but may be two-phase motors or four or more-phase motors.

[0146] In the first and third to fifth embodiments, the motor is not limited to a permanent magnet synchronous machine having a permanent magnet as a field pole on the rotor, but may be a wound field synchronous machine having a field winding as a field pole on the rotor. In this case, the rotor may be provided with both a field winding and a permanent magnet.

[0147] In each of the above embodiments, the motor is not limited to a synchronous motor, and may be an induction motor.

[0148] The control device that performs the temperature increase / drive control is not limited to the motor ECU 110. For example, each control may be performed by a plurality of control devices, such as the battery ECU 100, the EVECU 120, and the motor ECU 110, working together.

[0149] The moving body on which the control system 20 is mounted is not limited to a vehicle, and may be, for example, an aircraft or a ship.

[0150] The control device and method described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control device and method described herein may be implemented by a special-purpose computer configured with a processor comprising one or more dedicated hardware logic circuits. Alternatively, the control device and method described herein may be implemented by one or more special-purpose computers configured with a combination of a processor and memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by a computer.

[0151] - The following describes characteristic configurations extracted from the above-described embodiments. [Configuration 1] A control device (110) applied to a system including: a first inverter (30) having first upper and lower arm switches (SAH, SAL) of multiple phases, a first motor (40) having first armature windings (41U to 41W) electrically connected to low potential side terminals of the first upper arm switches of each phase and high potential side terminals of the first lower arm switches of each phase, a second inverter (50) having second upper and lower arm switches (SBH, SBL) of multiple phases, and a second motor (60) having second armature windings (61U to 61W) electrically connected to low potential side terminals of the second upper arm switches of each phase and high potential side terminals of the second lower arm switches of each phase, wherein the system includes: a high potential side path (32H) electrically connecting a positive terminal of a power storage unit to the high potential side terminals of the first upper arm switches and the second upper arm switches; a low potential side path (32L) electrically connecting the negative terminal of the power storage unit and low potential side terminals of the first lower arm switch and the second lower arm switch; a temperature rise determination unit (130) that determines whether or not there is a temperature rise request for the temperature rise target parts (21, 22); a drive determination unit (131) that determines whether or not there is a drive request to generate torque by at least one of the first motor and the second motor; and a switch control unit (132) that, when it is determined that there is a temperature rise request and that there is a drive request, performs temperature rise control for the temperature rise target parts and performs switching control of the first and second inverters to generate torque by at least the second motor of the first and second motors.[Configuration 2] The control device according to Configuration 1, wherein the power storage unit is composed of a first power storage unit (21) and a second power storage unit (22) connected in series, the system includes a connection path (73) that electrically connects 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 (OA) of the first armature winding, and the switch control unit performs, as the temperature rise control, control to switch on and off the first upper and lower arm switches so as to flow a current between the first power storage unit and the second power storage unit via the first inverter, the first armature winding, and the connection path, and performs, as drive control to generate torque by the second motor, control to switch on and off the second upper and lower arm switches. [Configuration 3] The control device according to Configuration 2, wherein the system includes a field winding (210) constituting a rotor (42) of the first motor, and a field energization circuit (211) that supplies current to the field winding from the first and second power storage units, and the switch control unit controls the field energization circuit so that no current flows through the field winding during execution of the temperature rise control. [Configuration 4] The control device according to Configuration 2, wherein the system includes a power transmission unit (220) that controls a power transmission state between the rotor (42) of the first motor and a rotationally driven object (12F) of the first motor, and the switch control unit controls the power transmission unit to interrupt power transmission from the rotor to the rotationally driven object during execution of the temperature rise control. [Configuration 5] The control device according to Configuration 1, further comprising a selection unit (133) that selects at least one of the set (301) of the first inverter and the first motor and the set (302) of the second inverter and the second motor, wherein the switch control unit increases a d-axis current flowing through an armature winding that constitutes the selected set of the first armature winding and the second armature winding, or reduces a gate voltage of an inverter that constitutes the selected set of the first inverter and the second inverter, in the temperature rise control. [Configuration 6] The control device according to Configuration 5, wherein the selection unit alternately switches between the set of the first inverter and the first motor and the set of the second inverter and the second motor as the set for which temperature rise control is to be performed.[Configuration 7] The control device according to any one of configurations 1 to 6, wherein the switch control unit performs switching control of either the first inverter or the second inverter for the temperature increase control when it determines that a parameter (Ptgt*) indicating a temperature increase request degree of the temperature increase target part is greater than a first threshold (PthL) and is equal to or less than a second threshold (PthH) that is greater than the first threshold, and performs switching control of the first inverter and the second inverter for the temperature increase control when it determines that the parameter is greater than the second threshold. [Configuration 8] The control device according to any one of configurations 1 to 7, wherein the system includes a heat transfer unit (200, 201) that transfers heat generated in at least one of a set of the first inverter and the first motor and a set of the second inverter and the second motor to the temperature increase target part.

[0152] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A control device (110) applied to a system including: a first inverter (30) having first upper and lower arm switches (SAH, SAL) of multiple phases; a first motor (40) having first armature windings (41U to 41W) electrically connected to the low potential side terminals of the first upper arm switches of each phase and the high potential side terminals of the first lower arm switches of each phase; a second inverter (50) having second upper and lower arm switches (SBH, SBL) of multiple phases; and a second motor (60) having second armature windings (61U to 61W) electrically connected to the low potential side terminals of the second upper arm switches of each phase and the high potential side terminals of the second lower arm switches of each phase, wherein the system includes: a high potential side path (32H) electrically connecting a positive terminal of a power storage unit to the high potential side terminals of the first upper arm switches and the second upper arm switches; a low potential side path (32L) electrically connecting the negative terminal of the power storage unit and low potential side terminals of the first lower arm switch and the second lower arm switch; a temperature rise determination unit (130) that determines whether or not there is a temperature rise request for the temperature rise target parts (21, 22); a drive determination unit (131) that determines whether or not there is a drive request to generate torque by at least one of the first motor and the second motor; and a switch control unit (132) that, when it is determined that there is a temperature rise request and that there is a drive request, performs temperature rise control for the temperature rise target parts and performs switching control of the first and second inverters to generate torque by at least the second motor of the first and second motors.

2. The control device according to claim 1, wherein the storage unit is composed of a first storage unit (21) and a second storage unit (22) connected in series, the system includes a connection path (73) that electrically connects the negative side of the first storage unit and the positive side of the second storage unit with a neutral point (OA) of the first armature winding, and the switch control unit performs, as the temperature rise control, control to switch the first upper and lower arm switches so as to pass current between the first storage unit and the second storage unit via the first inverter, the first armature winding, and the connection path, and performs, as drive control to generate torque by the second motor, control to switch the second upper and lower arm switches.

3. The control device according to claim 2, wherein the system comprises a field winding (210) constituting the rotor (42) of the first motor, and a field energization circuit (211) that supplies current from the first and second power storage units to the field winding, and the switch control unit controls the field energization circuit so that no current flows through the field winding while the temperature rise control is being performed.

4. The control device described in claim 2, wherein the system includes a power transmission unit (220) that controls the power transmission state between the rotor (42) of the first motor and the rotationally driven object (12F) of the first motor, and the switch control unit controls the power transmission unit to cut off the power transmission from the rotor to the rotationally driven object while the temperature rise control is being performed.

5. A control device as described in claim 1, comprising a selection unit (133) that selects at least one of the set (301) of the first inverter and the first motor and the set (302) of the second inverter and the second motor, and wherein the switch control unit increases the d-axis current flowing through the armature winding that constitutes the selected set of the first armature winding and the second armature winding, or reduces the gate voltage of the inverter that constitutes the selected set of the first inverter and the second inverter, during the temperature rise control.

6. The control device according to claim 5, wherein the selection unit alternately switches between the pair of the first inverter and the first motor and the pair of the second inverter and the second motor as the pair for which temperature rise control is to be performed.

7. The control device according to any one of claims 1 to 6, wherein the switch control unit, when determining that a parameter (Ptgt*) indicating the degree of temperature increase required for the part to be heated is greater than a first threshold value (PthL) and is equal to or less than a second threshold value (PthH) greater than the first threshold value, performs switching control of either the first inverter or the second inverter for the temperature increase control, and when determining that the parameter is greater than the second threshold value, performs switching control of the first inverter and the second inverter for the temperature increase control.

8. A control device as described in claim 5 or 6, wherein the system is provided with a heat transfer unit (200, 201) that transfers heat generated in at least one of the set of the first inverter and the first motor and the set of the second inverter and the second motor to the temperature-raising target part.

9. A program applied to a system including: a first inverter (30) having first upper and lower arm switches (SAH, SAL) of multiple phases; a first motor (40) having first armature windings (41U to 41W) electrically connected to the low potential side terminals of the first upper arm switches of each phase and the high potential side terminals of the first lower arm switches of each phase; a second inverter (50) having second upper and lower arm switches (SBH, SBL) of multiple phases; and a second motor (60) having second armature windings (61U to 61W) electrically connected to the low potential side terminals of the second upper arm switches of each phase and the high potential side terminals of the second lower arm switches of each phase, wherein the system includes: a high potential side path (32H) electrically connecting a positive terminal of a power storage unit to the high potential side terminals of the first upper arm switches and the second upper arm switches; and a low potential side path (32L) electrically connecting the negative terminal of the power storage unit and the low potential side terminals of the first lower arm switch and the second lower arm switch, wherein the program causes a processor (111) to execute: a temperature rise processing determination process that determines whether or not there is a temperature rise request for the temperature rise target parts (21, 22); a drive determination process that determines whether or not there is a drive request to generate torque by at least one of the first motor and the second motor; and a control process that, when it is determined that there is a temperature rise request and that there is a drive request, performs temperature rise control for the temperature rise target parts and performs switching control of the first and second inverters to generate torque by at least the second motor of the first and second motors.

10. A control method applied to a system including: a first inverter (30) having first upper and lower arm switches (SAH, SAL) of multiple phases; a first motor (40) having first armature windings (41U to 41W) electrically connected to the low potential side terminals of the first upper arm switches of each phase and the high potential side terminals of the first lower arm switches of each phase; a second inverter (50) having second upper and lower arm switches (SBH, SBL) of multiple phases; and a second motor (60) having second armature windings (61U to 61W) electrically connected to the low potential side terminals of the second upper arm switches of each phase and the high potential side terminals of the second lower arm switches of each phase, wherein the system includes: a high potential side path (32H) electrically connecting a positive terminal of a power storage unit to the high potential side terminals of the first upper arm switches and the second upper arm switches; a low potential side path (32L) electrically connecting the negative terminal of the storage unit and the low potential side terminals of the first lower arm switch and the second lower arm switch; a temperature rise determination step of determining whether or not there is a temperature rise request for a temperature rise target part (21, 22); a drive determination step of determining whether or not there is a drive request to generate torque by at least one of the first motor and the second motor; and a control step of performing temperature rise control for the temperature rise target part and performing switching control of the first and second inverters to generate torque by at least the second motor of the first and second motors when it is determined that there is a temperature rise request and that there is a drive request.

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