Control device, program, and control method

Abstract

To provide a control device that can secure a sufficient amount of heat to raise the temperature of the object to be heated. [Solution] The control device 50 is applied to a power conversion system 100 comprising a rotating electric machine 10 and an inverter 20. The power conversion system comprises a high-potential side path 22H, a low-potential side path 22L, a connection path 73 that electrically connects the negative terminal of the first battery 31 and the positive terminal of the second battery 32 and the neutral point O of each phase armature winding 11U, 11V, and 11W. The control device 50 comprises a command generation unit that generates drive commands for the upper arm switch and the lower arm switch, and a switch control unit that performs switching control of each switch SUH to SWL based on the drive commands generated by the command generation unit. The command generation unit generates drive commands such that the current conditions are met, that an AC path current flows through the connection path 73 and an AC d-axis current flows through each phase armature winding 11U, 11V, and 11W.

Description

Technical Field

[0001] The present disclosure relates to a control device, a program, and a control method.

Background Art

[0002] Conventionally, a control device applied to a system including a rotating electric machine, an inverter, and a connection path has been known. The rotating electric machine has a plurality of phase armature windings. The inverter has switches for upper and lower arms corresponding to the number of phases. The switches of the upper and lower arms are electrically connected to the armature windings of each phase and a first power storage unit and a second power storage unit connected in series. The connection path connects the neutral point of the star-connected armature windings, the negative terminal of the first power storage unit, and the positive terminal of the second power storage unit.

[0003] The control device performs switching control of the switches of the upper and lower arms so that an alternating current path current flows through the connection path. As a result, power is transferred between the first power storage unit and the second power storage unit via the inverter, the armature windings, and the connection path, and each power storage unit generates heat as it is energized. The heat generated as each power storage unit is energized is used to raise the temperature of the temperature-rising target. Note that, as such a control device, for example, there is a device described in Patent Document 1.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, due to the small heat generation of each power storage unit during the implementation of the above-described switching control, there is a possibility that a sufficient amount of heat for raising the temperature of the temperature-rising target cannot be ensured. In this case, there is a concern that the temperature of the temperature-rising target cannot be appropriately raised.

[0006] The primary object of this disclosure is to provide a control device, program, and control method that can secure a sufficient amount of heat to raise the temperature of an object to be heated. [Means for solving the problem]

[0007] This disclosure relates to a rotating electric machine having multiple phase armature windings, An inverter having upper arm switches and lower arm switches for each phase, wherein in each phase, the low-potential terminal of the upper arm switch and the high-potential terminal of the lower arm switch are electrically connected to the armature winding, In a control device applied to a system comprising: The aforementioned system, A high-potential side path electrically connects the positive terminal of the first energy storage unit and the high-potential side terminal of the upper arm switch, A low-potential side path electrically connects the negative terminal of the second energy storage unit and the low-potential side terminal of the lower arm switch, A connection path electrically connects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit to the neutral point of the star-connected armature winding, Equipped with, A command generation unit that generates drive commands for the upper arm switch and the lower arm switch, A switch control unit performs switching control of the upper arm switch and the lower arm switch based on the drive command generated by the command generation unit, Equipped with, The command generation unit generates the drive command such that it satisfies the current conditions that an alternating current path current flows through the connection path and an alternating current d-axis current flows through the armature windings of each phase.

[0008] In the system described above, in order to secure sufficient heat to raise the temperature of the object to be heated, it is conceivable to utilize the heat generated by the armature winding, upper arm switch, and lower arm switch in addition to the heat generated by the energization of each energy storage unit. In this case, there is a concern that sufficient phase current may not be able to flow to generate heat in the armature winding, upper arm switch, and lower arm switch due to the AC path current being limited within a predetermined current limit range.

[0009] Therefore, in this disclosure, a drive command is generated to satisfy the current conditions that an AC path current flows through the connection path and an AC d-axis current flows through the armature winding of each phase. When switching control is performed based on the generated drive command, it is possible to increase the magnitude of the phase current corresponding to the d-axis compared to the case where no d-axis current flows through the armature winding of each phase. Here, the AC d-axis current is a current that flows to maintain the sum of the phase currents and has little effect on the path current. For this reason, when switching control is performed to satisfy the current conditions, it is possible to promote heat generation in the armature winding, upper arm switch and lower arm switch while allowing path current to flow within the current limit range. As a result, a sufficient amount of heat can be secured to raise the temperature of the object to be heated, and the temperature of the object to be heated can be raised appropriately. [Brief explanation of the drawing]

[0010] [Figure 1] Overall configuration diagram of the power conversion system according to the first embodiment. [Figure 2] A diagram illustrating the overview of the thermal management system. [Figure 3] A time chart showing the changes in path current and d-axis current. [Figure 4] A functional block diagram showing the processes performed by the control unit. [Figure 5] A diagram illustrating the d-axis command current and path command current. [Figure 6] A flowchart illustrating the processing procedure for temperature rise control. [Figure 7] A time chart showing an example of temperature rise control. [Figure 8] A time chart showing an example of temperature increase control according to the second embodiment. [Figure 9] A time chart showing an example of temperature increase control. [Figure 10] A time chart showing an example of temperature increase control according to the third embodiment. [Figure 11] A time chart showing an example of temperature increase control. [Figure 12] A time chart showing an example of temperature increase control. [Figure 13] A time chart showing an example of temperature increase control according to a modification of the third embodiment. [Figure 14] A time chart showing an example of temperature increase control. [Figure 15] A time chart showing an example of temperature increase control according to the fourth embodiment. [Figure 16] A flowchart showing the processing procedure of temperature increase control according to the fifth embodiment. [Figure 17] An overall configuration diagram of a power conversion system according to other embodiments.

Embodiments for Carrying Out the Invention

[0011] While referring to the drawings, a plurality of embodiments will be described. In the plurality of embodiments, parts that functionally and / or structurally correspond and / or are associated may be assigned the same reference numerals, or reference numerals that differ in the hundreds digit or more. For corresponding parts and / or associated parts, the description of other embodiments can be referred to.

[0012] <First Embodiment> Hereinafter, a first embodiment in which a control device according to the present invention is embodied will be described while referring to the drawings. The control device of this embodiment constitutes a power conversion system mounted on an electric vehicle such as an electric car or a hybrid car.

[0013] As shown in Figure 1, the power conversion system 100 comprises a rotating electric machine 10, an inverter 20, a high-potential path 22H, and a low-potential path 22L. The rotating electric machine 10 is a three-phase synchronous machine and comprises U, V, and W phase armature windings 11U, 11V, and 11W, and a rotor 12. The rotating electric machine 10 is, for example, a permanent magnet synchronous machine. In this case, the rotor 12 has permanent magnets as field poles. The U, V, and W phase armature windings 11U, 11V, and 11W are connected in a star configuration and are arranged with an electrical angle offset of 120° each. The rotor 12 is capable of transmitting power to the vehicle's drive wheels 13. Therefore, the rotating electric machine 10 becomes the source of torque that drives the vehicle.

[0014] The inverter 20 is equipped with three series connections of upper and lower arm switches. Specifically, the inverter 20 is equipped with U, V, W phase upper arm switches SUH, SVH, SWH and U, V, W phase lower arm switches SUL, SVL, SWL. Freewheeling diodes, U, V, W phase upper arm diodes DUH, DVH, DWH, which are U, V, W phase upper arm diodes, are connected in antiparallel to the U, V, W phase upper arm switches SUH, SVH, SWH. Freewheeling diodes, U, V, W phase lower arm diodes, DUL, DVL, DWL, which are U, V, W phase lower arm diodes, are connected in antiparallel to the U, V, W phase lower arm switches SUL, SVL, SWL. In this embodiment, each switch SUH, SVH, SWH, SUL, SVL, SWL is an IGBT. In this case, the high-potential side terminal is the collector and the low-potential side terminal is the emitter.

[0015] The collectors of the U, V, W phase upper arm switches SUH, SVH, and SWH are connected to the high-potential path 22H. The emitters of the U, V, W phase lower arm switches SUL, SVL, and SWL are connected to the low-potential path 22L. The high-potential path 22H and the low-potential path 22L are electrical paths such as busbars.

[0016] The inverter 20 is equipped with a smoothing capacitor 21. A high-potential path 22H is connected to the high-potential terminal of the smoothing capacitor 21. A low-potential path 22L is connected to the low-potential terminal of the smoothing capacitor 21. The smoothing capacitor 21 may be provided outside the inverter 20.

[0017] In each phase, the first ends of the armature windings 11U, 11V, and 11W are connected to the connection points between the emitters of the upper arm switches SUH, SVH, and SWH and the collectors of the lower arm switches SUL, SVL, and SWL via conductive members 23 such as busbars. The second ends of each phase armature winding 11U, 11V, and 11W are connected at the neutral point O. In this embodiment, the number of turns of each phase armature winding 11U, 11V, and 11W is set to be the same. As a result, the inductance of each phase armature winding 11U, 11V, and 11W is set to be the same.

[0018] The power conversion system 100 includes a first battery 31 (corresponding to the "first energy storage unit") and a second battery 32 (corresponding to the "second energy storage unit"). Each battery 31 and 32 serves as a power source for rotating the rotor 12 of the rotating electric machine 10. Each battery 31 and 32 is a battery pack comprising a series connection of multiple unit batteries. A unit battery is either a single battery cell or a series connection of multiple battery cells. The terminal voltages (e.g., rated voltages) of each battery cell constituting the battery pack are set to be the same, for example. The battery cells are secondary batteries such as lithium-ion batteries.

[0019] In this embodiment, the full charge capacity (specifically, for example, the rated full charge capacity) [Ah] of each unit cell constituting the first battery 31 and the second battery 32 is the same. Furthermore, the terminal voltage (e.g., rated voltage) of the first battery 31 is higher than the terminal voltage (e.g., rated voltage) of the second battery 32. This configuration can be achieved, for example, by increasing the number of unit cells constituting the first battery 31 compared to the number of unit cells constituting the second battery 32.

[0020] The positive terminal of the first battery 31 is connected to the high-potential path 22H. The negative terminal of the first battery 31 is connected to the positive terminal of the second battery 32. The negative terminal of the second battery 32 is connected to the low-potential path 22L.

[0021] The power conversion system 100 is equipped with power switches for electrically connecting or disconnecting the first and second storage batteries 31 and 32 and the inverter 20. Specifically, the power switches include a high-potential side main switch SMRH, a low-potential side main switch SMRL, and a pre-charge switch SMRP. In this embodiment, each of the main switches SMRH, SMRL and the pre-charge switch SMRP is a mechanical relay. Each of the main switches SMRH, SMRL and the pre-charge switch SMRP prevents the flow of current in both directions when turned off, and allows the flow of current in both directions when turned on. The high-potential side main switch SMRH is provided in the high-potential side path 22H. The low-potential side main switch SMRL is provided in the low-potential side path 22L. A series connection of the pre-charge switch SMRP and the pre-charge resistor 40 is connected in parallel to the low-potential side main switch SMRL. Note that each of the main switches SMRH, SMRL and the pre-charge switch SMRP is not limited to mechanical relays, but may also be, for example, semiconductor switching elements.

[0022] Each of the batteries 31 and 32 can be charged from an external charger located outside the vehicle via external charging control. The external charger is, for example, a stationary charger.

[0023] Each of the batteries 31 and 32 can supply power to external power supply targets outside the vehicle via external power supply control. External power supply control when the power supply target is a grid power source is also called V2G (Vehicle to Grid). External power supply control when the power supply target is electrical equipment in a building such as a residence is also called V2H (Vehicle to Home).

[0024] The power conversion system 100 includes a high-potential side connection switch DCRH and a low-potential side connection switch DCRL. Each connection switch DCRH and DCRL is a switch for electrically connecting or disconnecting the external charger or power supply unit from the first and second storage batteries 31 and 32. In this embodiment, each connection switch DCRH and DCRL is a mechanical relay. When each connection switch DCRH and DCRL is turned off, it prevents the flow of current in both directions, and when turned on, it allows the flow of current in both directions. The high-potential side connection switch DCRH is provided in the high-potential side path 22H in the portion closer to the inverter 20 than the high-potential side main switch SMRH. The low-potential side connection switch DCRL is provided in the low-potential side path 22L in the portion closer to the inverter 20 than the low-potential side main switch SMRL. Note that each connection switch DCRH and DCRL is not limited to a mechanical relay, but may also be, for example, a semiconductor switching element.

[0025] The power conversion system 100 includes a first motor-side switch 71, a second motor-side switch 72, and a connection path 73 for switching the connection state of the first battery 31 and the second battery 32. The connection path 73 is an electrical path that connects the negative terminal of the first battery 31 and the positive terminal of the second battery 32 to the neutral point O. The connection path 73 is provided with the first motor-side switch 71 and the second motor-side switch 72 in order from each battery 31 and 32.

[0026] Each motor-side switch 71, 72 is a mechanical relay. When each motor-side switch 71, 72 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 each motor-side switch 71, 72 is not limited to mechanical relays, but may also be, for example, a semiconductor switching element. In this embodiment, the first battery 31 and the second battery 32 constitute the battery unit 30.

[0027] The power conversion system 100 includes a neutral point capacitor 74, which is a capacitor connecting the connection path 73 and the low-potential side path 22L. The first end of the neutral point capacitor 74 is connected to the portion of the connection path 73 between the first motor-side switch 71 and the second motor-side switch 72. The second end of the neutral point capacitor 74 is connected to the portion of the low-potential side path 22L that is closer to the inverter 20 than the low-potential side main switch SMRL and the pre-charge switch SMRP.

[0028] When the first motor-side switch 71 is turned on, the first terminal of the neutral point capacitor 74 is electrically connected to the negative terminal of the first battery 31 and the positive terminal of the second battery 32. On the other hand, when the first motor-side switch 71 is turned off, the first terminal of the neutral point capacitor 74 is electrically disconnected to the negative terminal of the first battery 31 and the positive terminal of the second battery 32. When the second motor-side switch 72 is turned on, the neutral point O of each phase armature winding 11U, 11V, and 11W is electrically connected to the first terminal of the neutral point capacitor 74. On the other hand, when the second motor-side switch 72 is turned off, the neutral point O and the first terminal of the neutral point capacitor 74 are electrically disconnected.

[0029] As shown in Figure 2, the power conversion system 100 includes a thermal management system 110 and a heating device 115. The thermal management system 110 manages the heat generated in the rotating electric machine 10, the inverter 20, and the battery unit 30. The heating device 115 uses the heat transferred from the rotating electric machine 10, the inverter 20, and the battery unit 30 to heat the interior of the vehicle.

[0030] More specifically, the thermal management system 110 includes a circulation path 111 through which cooling water circulates, an electric water pump 112, a radiator 113, and an electric fan 114. The water pump 112 is powered and driven to circulate the cooling water. Downstream of the water pump 112 in the circulation path 111 are the inverter 20, the rotating electric machine 10, the battery unit 30, the radiator 113, and the heating device 115. The battery unit 30 is located downstream of the inverter 20 and the rotating electric machine 10 in the circulation path 111. In this case, the heat generated in each phase armature winding 11U, 11V, 11W and each phase upper and lower arm switch SUH~SWL is transferred to the respective storage batteries 31 and 32. In this embodiment, in the circulation path 111, the inverter 20, rotating electric machine 10, battery unit 30, radiator 113, and heating device 115 are arranged in order downstream of the water pump 112.

[0031] The radiator 113 cools the coolant that flows in through the circulation path 111 and supplies it to the water pump 112. The coolant flowing into the radiator 113 is cooled by the airflow blown onto the radiator 113 as the vehicle moves, and by the airflow blown onto the radiator 113 when the fan 114 is driven to rotate. In this embodiment, the circulation path 111 corresponds to the "heat transfer section".

[0032] Returning to the explanation of Figure 1, the power conversion system 100 is equipped with a current sensor, a voltage sensor, a rotation angle sensor 87, and a temperature sensor as sensors for detecting various physical quantities.

[0033] The current sensors are a first current sensor 81A, a second current sensor 81B, a phase current sensor 82, and a motor current sensor 83. The first current sensor 81A detects the current IH flowing through the first battery 31. The second current sensor 81B detects the current IL flowing through the second battery 32. The phase current sensor 82 detects the phase currents Iu, Iv, and Iw flowing through the U, V, and W phase armature windings 11U, 11V, and 11W. In this embodiment, for each phase, the sign of the phase currents Iu, Iv, and Iw is positive in the direction from the first end to the second end, and negative in the direction from the second end to the first end.

[0034] The motor current sensor 83 detects the path current Inr flowing through the connection path 73. In this embodiment, the motor current sensor 83 detects the current flowing in the portion of the connection path 73 closer to the neutral point O than the connection point with the neutral point capacitor 74. In this embodiment, the sign of the path current Inr flowing from the neutral point O to the negative terminal of the first battery 31 and the positive terminal of the second battery 32 is set to positive. The sign of the path current Inr flowing from the negative terminal of the first battery 31 and the positive terminal of the second battery 32 to the neutral point O is set to negative. The path current Inr is the current corresponding to the sum of the phase currents Iu, Iv, and Iw, and is also called the zero-sequence current.

[0035] The voltage sensors consist of a capacitor voltage sensor 84, a first voltage sensor 85A, a second voltage sensor 85B, and a power supply voltage sensor 86. The capacitor voltage sensor 84 detects the voltage VM of the neutral point capacitor 74. The first voltage sensor 85A detects the voltage VH of the first storage battery 31. The second voltage sensor 85B detects the voltage VL of the second storage battery 32. The power supply voltage sensor 86 detects the voltage Vdc of the smoothing capacitor 21.

[0036] The rotation angle sensor 87 detects the rotation angle of the rotor 12 (specifically, the electrical angle θe). The rotation angle sensor 87 detects the electrical angle θe based on the case where the magnetic pole center (d-axis) of the rotor 12 is facing the direction of the U-phase armature winding 11U.

[0037] The temperature sensors are a battery temperature sensor 88, a switch temperature sensor 89, and a motor temperature sensor 90. The battery temperature sensor 88 detects the temperature Tmb of the first battery 31 and the second battery 32. The switch temperature sensor 89 detects the temperature Tms of the upper and lower arm switches SUH~SWL for each phase. The motor temperature sensor 90 detects the temperature Tmw of the armature windings 11U, 11V, and 11W for each phase. The detected values ​​of each sensor 81A, 81B, 82, 83, 84, 85A, 85B, 86, 87, 88, 89, and 90 are input to the control device 50 of the power conversion system 100.

[0038] The control device 50 is an electronic control unit (ECU) that performs various controls on the power conversion system 100, and comprises a processor 51 and a memory unit 52 as hardware. In the control device 50, the processor 51 and the memory unit 52 are connected to each other via a communication bus. In the power conversion system 100, each in-vehicle device can be controlled by an ECU corresponding to each in-vehicle device. However, for convenience, Figure 1 shows multiple ECUs as a single control device 50.

[0039] The memory unit 52 includes memory and storage as hardware. The memory is a storage device for storing data used for processing by the control device 50. The memory provides the processor with a workspace for temporary use when the processor is performing processing. The memory includes, for example, ROM or RAM. The storage is a storage device that stores various programs and data for the processor to read and execute, and is a non-transitory tangible storage medium. The storage includes, for example, an HDD or flash memory. The storage stores program information for processing, such as that shown in Figures 6 and 16 described later.

[0040] For example, program information stored on a non-transitional physical recording medium is installed in the storage unit 52. The recording medium is, for example, a USB memory stick, CD-ROM, or DVD. Also, for example, program information transmitted via a communication network, such as OTA (Over The Air), is installed in the storage unit 52.

[0041] The control device 50 controls the on / off state of each main switch SMRH, SMRL, the precharge switch SMRP, each motor-side switch 71, 72, and each connection switch DCRH, DCRL. The control device 50 also controls the switching of each phase upper and lower arm switch SUH to SWL that constitute the inverter 20. Through the implementation of switching control, the upper arm switch and the lower arm switch are turned on alternately in each phase.

[0042] The control device 50 performs drive control to move the vehicle with the main switches SMRH and SMRL turned ON, and the precharge switch SMRP, the motor-side switches 71 and 72, and the connection switches DCRH and DCRL turned OFF. In drive control, the control device 50 performs switching control of the upper and lower arm switches SUH to SWL of each phase in order to feed back the control amount of the rotating electric machine 10 to a command value. The control amount is, for example, torque. The command value is notified to the control device 50 from a higher-level control device. When drive control is performed, the rotational power of the rotor 12 is transmitted to the drive wheels 13, and the vehicle moves.

[0043] The control device 50 performs temperature control to raise the temperature of the object to be heated. In this embodiment, the objects to be heated are the first battery 31 and the second battery 32. When the control device 50 performs temperature control, it turns on the main switches SMRH, SMRL and the motor-side switches 71, 72, and turns off the precharge switch SMRP and the connection switches DCRH, DCRL. In this case, the circuit including the upper and lower arm switches SUH~SWL for each phase, the armature windings 11U, 11V, 11W for each phase, the high-potential side path 22H, the low-potential side path 22L, and the connection path 73 is made capable of operating as a step-up / step-down chopper circuit that enables bidirectional power transmission between the first battery 31 and the second battery 32.

[0044] In temperature rise control, the control device 50 controls the switching of each phase upper and lower arm switch SUH to SWL so that an AC path current Inr flows through the connection path 73. As a result, current flows through each battery 31, 32, each phase upper and lower arm switch SUH to SWL, each phase armature winding 11U, 11V, 11W, the high-potential side path 22H, the low-potential side path 22L, and the connection path 73, and power is exchanged between the first battery 31 and the second battery 32. In this case, each battery 31, 32 generates heat when energized. The heat generated when each battery 31, 32 is energized is used to raise the temperature of each battery 31, 32.

[0045] Incidentally, due to the small amount of heat generated by each battery 31 and 32 during the temperature rise control process, it is possible that sufficient heat cannot be secured to raise the temperature of each battery 31 and 32. One possible reason for the small amount of heat generated by each battery 31 and 32 is the small equivalent series resistance of each battery 31 and 32.

[0046] If sufficient heat cannot be secured to raise the temperature of each battery 31, 32, there is a concern that the temperature increase request may not be properly met. For example, there is a concern that the time required to raise the battery temperature from the current value to the target value may be longer than the required temperature increase time. The temperature increase time may be a predetermined value (e.g., 1 minute) or a value notified by a higher-level control device.

[0047] In the power conversion system 100, in order to secure sufficient heat to raise the temperature of each battery 31, 32, it is conceivable to utilize the heat generated by the energization of each phase armature winding 11U, 11V, 11W and each phase upper and lower arm switch SUH~SWL, in addition to the heat generated by the energization of each battery 31, 32. In this case, there is a concern that sufficient phase current may not be able to flow to generate heat in each phase armature winding 11U, 11V, 11W and each phase upper and lower arm switch SUH~SWL due to the AC path current Inr being limited to a predetermined current limit range.

[0048] Therefore, in this embodiment, the control device 50 performs temperature rise control to satisfy the current conditions that an AC path current Inr flows and an AC d-axis current Idr flows through each phase armature winding 11U, 11V, and 11W. Below, the temperature rise control will be described assuming the vehicle is stationary.

[0049] Here, referring to Figure 3, we will explain how the amount of heat generated by the heating control can be increased while maintaining a path current Inr within the current limit range by performing heating control to satisfy the current conditions. In Figure 3, (a) shows the transition of the d-axis current Idr, (b) shows the transition of the path current Inr, (c) shows the transition of the U-phase current Iu, (d) shows the transition of the V-phase current Iv, and (e) shows the transition of the W-phase current Iw. In Figure 3, the transitions of each current Idr, Inr, Iu, Iv, and Iw when the current conditions are satisfied are shown by solid lines, and the transitions of each current Idr, Inr, Iu, Iv, and Iw in the comparative example where the current conditions are not satisfied are shown by dashed lines. In the comparative example, the d-axis current Idr is set to 0. The path current Inr is the same in this embodiment and the comparative example.

[0050] In the comparative example, the path current Inr is restricted within a current limit range (-INL < Inr < INL) defined by a predetermined limit value INL. In this case, increasing the magnitudes of the phase currents Iu, Iv, and Iw is restricted within the range where the amplitude of the path current Inr reaches the limit value INL. The limit value INL of the path current Inr is, for example, a value determined by the charging current acceptance performance of the first storage battery 31 and the second storage battery 32.

[0051] When the magnitude of the path current Inr is restricted, as indicated by the dashed lines in FIGS. 3(c) to (e), there may be room for increasing the amplitude with respect to the predetermined limit values IuL, IvL, and IwL of the phase currents Iu, Iv, and Iw. The limit values IuL, IvL, and IwL of the phase currents Iu, Iv, and Iw are, for example, values determined by the performance (specifically, the rated current) of the phase armature windings 11U, 11V, and 11W and the upper and lower arm switches SUH to SWL of each phase.

[0052] Here, the AC d-axis current Idr is a current that flows so as to maintain the sum of the phase currents Iu, Iv, and Iw, and is a current that has little influence on the path current Inr. As indicated by the solid lines in FIGS. 3(c) to (e), when the AC d-axis current flows, while the magnitude of the path current Inr is maintained, the magnitudes of the phase currents Iu, Iv, and Iw are increased compared to the case where the d-axis current Idr does not flow.

[0053] In view of the above points, in the present embodiment, temperature increase control is performed so as to satisfy the current conditions. In this case, while making the amplitude of the path current Inr less than the limit value INL, it becomes possible to promote heat generation in the phase armature windings 11U, 11V, and 11W and the upper and lower arm switches SUH to SWL of each phase. As a result, sufficient heat quantity can be ensured to increase the temperature of each storage battery 31 and 32, and the temperature increase requirement of the power conversion system 100 can be appropriately met.

[0054] Hereinafter, the temperature increase control will be described in detail.

[0055] FIG. 4 shows a functional block diagram of the temperature increase control executed in the control device 50.

[0056] The control device 50 includes a setting unit 60. The setting unit 60 determines whether or not there is a request for a temperature increase. A temperature increase request is a request to raise the temperature of the object to be heated.

[0057] For example, the setting unit 60 determines that there is a request for a temperature increase if it determines that the battery temperature is below a target value. Here, the battery temperature is, for example, the lower of the temperature of the first storage battery 31 and the second storage battery 32, or the average temperature of the first storage battery 31 and the second storage battery 32. The setting unit 60 can use the detected value Tmb of the battery temperature sensor 88 as the battery temperature. The target value of the battery temperature is notified, for example, from a higher-level control device. Note that a request for a temperature increase may be determined when the battery temperature is lower than the target value when the vehicle is stopped or running. Situations in which a request for a temperature increase is determined when the vehicle is stopped include, for example, when the battery temperature is lower than the target value immediately after the vehicle starts up, when the storage batteries 31 and 32 are externally charged, or when external power is supplied to the power supply target unit.

[0058] When the setting unit 60 determines that there is a request for temperature increase, it sets the d-axis command current Id* and the path command current In* to satisfy the current conditions. In this embodiment, as shown in Figure 5(a), the setting unit 60 sets the d-axis command current Id* to an AC waveform with amplitude Ida and period Td. In this case, the frequency of the d-axis command current Id* is fd = 1 / Td. As shown in Figure 5(b), the setting unit 60 sets the path command current In* to an AC waveform with amplitude Ina and period Tn. In this case, the frequency of the path command current In* is fn = 1 / Tn. The setting unit 60 also sets the q-axis command current Iq* to 0.

[0059] Specifically, the setting unit 60 sets the amplitudes Ina, Ida and angular frequencies ωn, ωd of each command current In*, Id*, which are represented as sine waves. In this case, the path command current In* is represented as a sine wave as shown in equation (eq1) below, and the d-axis command current Id* is represented as a sine wave as shown in equation (eq2) below.

[0060] In* = Ina·sin(ωn·t) (eq1) Id*=Ida·sin(ωd·t+θd) (eq2) In the right-hand side of equation (eq2) above, θd is the d-axis current phase of the d-axis command current Id* with respect to the path command current In*. The d-axis current phase θd corresponds to the phase difference between the path command current In* and the d-axis command current Id*. In this embodiment, the sign of the d-axis current phase θd is positive when the d-axis command current Id* lags behind the path command current In*, and negative when the d-axis command current Id* leads the path command current In*. In Figure 5, the path command current In* when the electrical angle θe = 0 is taken as the reference value (here, 0), and the advance of the electrical angle θe from electrical angle θe = 0 until the d-axis command current Id* reaches the reference value is shown as the d-axis current phase θd (<0). In this embodiment, the setting unit 60 sets the d-axis current phase θd of the d-axis command current Id* to a predetermined fixed value.

[0061] The control device 50 is configured to perform current feedback control of the d and q axis currents Idr and Iqr and includes d and q axis deviation calculation units 61d and 61q, d and q axis current control units 62d and 62q, and a three-phase conversion unit 63.

[0062] The d-axis deviation calculation unit 61d receives the d-axis command current Id* and the d-axis current Idr set by the setting unit 60. The d-axis deviation calculation unit 61d can use a value calculated based on each phase current Iu, Iv, Iw and the electrical angle θe as the d-axis current Idr. The q-axis deviation calculation unit 61q receives the q-axis command current Iq* and the q-axis current Iqr set by the setting unit 60. The q-axis deviation calculation unit 61q can use a value calculated based on each phase current Iu, Iv, Iw and the electrical angle θe as the q-axis current Iqr. The detected values ​​from the phase current sensor 82 can be used as each phase current Iu, Iv, Iw. The detected value from the rotation angle sensor 87 can be used as the electrical angle θe.

[0063] The d-axis deviation calculation unit 61d calculates the d-axis current deviation ΔId by subtracting the d-axis current Idr from the d-axis command current Id*. The q-axis deviation calculation unit 61q calculates the q-axis current deviation ΔIq by subtracting the q-axis current Iqr from the q-axis command current Iq*.

[0064] The d-axis current control unit 62d receives the d-axis current deviation ΔId calculated by the d-axis deviation calculation unit 61d as input. The d-axis current control unit 62d calculates the d-axis command voltage Vd* as an manipulated variable for feedback control to set the d-axis current deviation ΔId to 0.

[0065] The q-axis current control unit 62q receives the q-axis current deviation ΔId calculated by the q-axis deviation calculation unit 61q as input. The q-axis current control unit 62q calculates the q-axis command voltage Vq* as an manipulated variable for feedback control to set the q-axis current deviation ΔIq to 0.

[0066] The 3-phase conversion unit 63 receives the d and q axis command voltages Vd* and Vq* and the electrical angle θe as input. Based on the input d and q axis command voltages Vd* and Vq* and the electrical angle θe, the 3-phase conversion unit 63 calculates the U, V, and W phase command voltages Vu*, Vv*, and Vw* in the 3-phase fixed coordinate system. Each phase command voltage Vu*, Vv*, and Vw* is a sinusoidal signal with a phase shift of 120 degrees by the electrical angle θe.

[0067] The control device 50 includes a zero-sequence deviation calculation unit 64 and a zero-sequence control unit 65 as a configuration for performing current feedback control of the path current Inr. The zero-sequence deviation calculation unit 64 receives the path command current In* set by the setting unit 60 and the path current Inr as input. For example, the detected value of the motor current sensor 83 can be used as the path current Inr. The zero-sequence deviation calculation unit 64 calculates the path current deviation ΔIn by subtracting the path current Inr from the path command current In*.

[0068] The zero-sequence control unit 65 receives the path current deviation ΔIn calculated by the zero-sequence deviation calculation unit 64 as input. The zero-sequence control unit 65 calculates the zero-sequence command voltage Vn* as an manipulated variable for feedback control to set the path current deviation ΔIn to zero.

[0069] The control device 50 is configured to generate drive commands for each phase upper and lower arm switch SUH to SWL and includes U, V, and W phase superposition units 66U, 66V, and 66W, U, V, and W phase division units 67U, 67V, and 67W, and a command generation unit 68. The U phase superposition unit 66U receives the U phase command voltage Vu* calculated by the three-phase conversion unit 63. The V phase superposition unit 66V receives the V phase command voltage Vv* calculated by the three-phase conversion unit 63. The W phase superposition unit 66W receives the W phase command voltage Vw* calculated by the three-phase conversion unit 63. Each phase superposition unit 66U, 66V, and 66W receives the zero-phase command voltage Vn* calculated by the zero-phase control unit 65.

[0070] The U-phase superposition unit 66U calculates the superimposed U-phase command voltage "Vu* + Vn*" by adding the zero-sequence command voltage Vn* to the input U-phase command voltage Vu*. The superimposed U-phase command voltage is input to the U-phase division unit 67U. The V-phase superposition unit 66V calculates the superimposed V-phase command voltage "Vv* + Vn*" by adding the zero-sequence command voltage Vn* to the input V-phase command voltage Vv*. The superimposed V-phase command voltage is input to the V-phase division unit 67V. The W-phase superposition unit 66W calculates the superimposed W-phase command voltage "Vw* + Vn*" by adding the zero-sequence command voltage Vn* to the input W-phase command voltage Vw*. The superimposed W-phase command voltage is input to the W-phase division unit 67W.

[0071] The U-phase division unit 67U calculates the U-phase modulation ratio Mu by dividing the input superimposed U-phase command voltage by the power supply voltage Vdc. The V-phase division unit 67V calculates the V-phase modulation ratio Mv by dividing the input superimposed V-phase command voltage by the power supply voltage Vdc. The W-phase division unit 67W calculates the W-phase modulation ratio Mw by dividing the input superimposed W-phase command voltage by the power supply voltage Vdc. For example, the detected value of the power supply voltage sensor 86 can be used as the power supply voltage Vdc.

[0072] The command generation unit 68 receives the phase modulation rates Mu, Mv, and Mw calculated by the phase division units 67U, 67V, and 67W. Based on the input phase modulation rates Mu, Mv, and Mw, the command generation unit 68 generates drive signals for the upper and lower arm switches SUH to SWL for each phase. The drive signals are either ON commands or OFF commands. Specifically, the command generation unit 68 generates drive signals for the upper and lower arm switches SUH to SWL for each phase based on a comparison of the magnitudes of the phase modulation rates Mu, Mv, and Mw with the carrier signal. For example, the carrier signal is a triangular wave signal with equal increasing and decreasing speeds.

[0073] The control device 50 includes a switch control unit 69. The switch control unit 69 receives drive signals for each phase upper and lower arm switch SUH to SWL, which are generated by the command generation unit 68. Based on the input drive signals, the switch control unit 69 controls the charge and discharge current of the gates of each phase upper and lower arm switch SUH to SWL. As a result, each phase upper and lower arm switch SUH to SWL is controlled to be on or off according to the drive signals.

[0074] Figure 6 shows the processing procedure for temperature rise control performed by the control device 50. This control is performed repeatedly, for example, at a predetermined control cycle.

[0075] In step S10, the setting unit 60 determines whether or not there is a request for temperature increase. If it is determined that there is no request for temperature increase, this control is terminated. On the other hand, if it is determined that there is a request for temperature increase, the setting unit 60 sets the q-axis command current Iq* to 0 and proceeds to step S11. By executing the processes in steps S11 to S15, the AC d-axis command current Id* and the AC path command current In* are set.

[0076] In step S11, the setting unit 60 sets the angular frequency ωn of the path command current In*. In this embodiment, the angular frequency ωn of the path command current In* is set based on the frequency dependence of the internal resistance value (i.e., impedance value) of each battery 31, 32. For example, the angular frequency ωn of the path command current In* is set to the value among the settable angular frequency ωn values ​​that maximizes the internal resistance value of each battery 31, 32. This makes it possible to realize a configuration suitable for increasing the heat generated when each battery 31, 32 is energized.

[0077] In step S12, the setting unit 60 sets the amplitude Ina of the path command current In*. In this embodiment, the amplitude Ina of the path command current In* is set based on the temperature rise amount, which is the difference between the current battery temperature and the target temperature. For example, when the temperature rise amount is large, the amplitude Ina of the path command current In* is set to a larger value compared to when the temperature rise amount is small. This suppresses the increase in the time required to raise the battery temperature to the target value as the temperature rise amount increases.

[0078] In step S12, the setting unit 60 may set the amplitude Ina of the path command current In* based on at least one of the following: the amount of temperature rise, the internal resistance value of each battery 31, 32, and the temperature rise time. The internal resistance value of each battery 31, 32 may be a value calculated based on at least one of the following: the currents IH, IL flowing through each battery 31, 32, the voltages VH, VL of each battery 31, 32, and the battery temperature. The currents IH, IL flowing through each battery 31, 32 can be the detected values ​​of the corresponding current sensors 81A, 81B. The voltages VH, VL of each battery 31, 32 can be the detected values ​​of the corresponding voltage sensors 85A, 85B. The battery temperature can be the detected value Tmb of the battery temperature sensor 88.

[0079] In step S13, the setting unit 60 sets the angular frequency ωd of the d-axis command current Id*. In this embodiment, the angular frequency ωd of the d-axis command current Id* is set to the same value as the angular frequency ωn of the path command current In*. In this case, in addition to the current condition, the temperature rise control is performed so as to satisfy the frequency condition that a d-axis current Idr with the same frequency as the path current Inr's frequency fn flows.

[0080] In step S14, the setting unit 60 sets the amplitude Ida of the d-axis command current Id*. In this embodiment, the amplitude Ida of the d-axis command current Id* is set based on the amount of temperature increase of the battery.

[0081] For example, the amplitudes Ina and Ida of each command current In* and Id* are set so that the sum of the temperature rises associated with the energization of each current Inr and Idr equals the total temperature increase. In this case, in step S12, the amplitude Ina of the path command current In* is set so that a portion of the temperature increase of the battery is covered by the temperature rise associated with the energization of the path current Inr. In step S14, the amplitude Ida of the d-axis command current Id* is set so that the remaining portion of the temperature increase, excluding the temperature rise associated with the energization of the path current Inr, is covered by the temperature rise associated with the energization of the d-axis current Idr.

[0082] In step S15, the setting unit 60 sets the d-axis current phase θd. In this embodiment, the d-axis current phase θd is set to a fixed value (for example, 0).

[0083] In step S16, the d,q axis deviation calculation units 61d,61q, the d,q axis current control units 62d,62q, and the three-phase conversion unit 63 perform current feedback control of the d,q axis currents Idr,Iqr to calculate the respective phase command voltages Vu*, Vv*, and Vw*. In this case, the d axis command current Id* set by the processing in steps S13 to S15 is used. The zero-sequence deviation calculation unit 64 and the zero-sequence control unit 65 perform current feedback control of the path current Inr to calculate the zero-sequence command voltage Vn*. In this case, the path command current In* set by the processing in steps S11 and S12 is used. The phase superposition units 66U,66V,66W and the phase division units 67U,67V,67W calculate the respective phase modulation rates Mu, Mv, and Mw based on the calculated respective command voltages Vu*, Vv*, Vw*, and Vn*. In the command generation unit 68, drive signals for the upper and lower arm switches SUH to SWL are generated based on the calculated phase modulation rates Mu, Mv, and Mw.

[0084] In step S17, the switch control unit 69 performs switching control of the upper and lower arm switches SUH to SWL for each phase based on the generated drive signal. This enables temperature rise control to be performed to satisfy the current conditions.

[0085] Figure 7 shows an example of the current transitions when temperature rise control is performed while the rotor 12 is stopped at an electrical angle θe = θa. In Figure 7, (a) shows the transition of the path current Inr, (b) shows the transition of the d-axis current Idr, (c) shows the transition of the U-phase current Iu, (d) shows the transition of the V-phase current Iv, (e) shows the transition of the W-phase current Iw, and (f) shows the transition of the d-axis current phase θd. Figure 7 shows a comparison of the waveforms of currents, etc., between this embodiment which satisfies the current conditions and a comparative example which does not satisfy the current conditions.

[0086] In the control example shown in Figure 7, the amplitude Ina of the path current Inr is maintained at 500[A] while a d-axis current Idr with amplitude Ida=400[A] is supplied. In this case, the magnitude (specifically, amplitude) of the U and V phase currents Iu and Iv is increased compared to the comparative example. In particular, the magnitude of the U phase current Iu is significantly increased. Therefore, compared to the comparative example, heat generation in the U and V phase armature windings 11U and 11V and the U and V phase upper and lower arm switches SUH, SUL, SVH, and SVL can be promoted, and the amount of heat generated by implementing temperature rise control can be increased.

[0087] In this embodiment, the d-axis current Idr supplied during temperature rise control is an alternating current. In this case, it becomes possible to set the angular frequency ωd (i.e., frequency fd) of the d-axis current Idr. This increases the degree of freedom in controlling each phase current Iu, Iv, and Iw that flows during the temperature rise control.

[0088] Specifically, in addition to the current condition, the temperature rise control is performed so as to satisfy the frequency condition that a d-axis current Idr flows with the same frequency as the path current Inr's frequency fn. In this case, compared to the case where the frequencies fn and fd of each current Inr and Idr are different values, the control design of the temperature rise control can be simplified while controlling each phase current Iu, Iv, and Iw that flows during the temperature rise control.

[0089] The power conversion system 100 is equipped with a circulation path 111. Heat generated in the upper and lower arm switches SUH~SWL and the armature windings 11U, 11V, and 11W of each phase is transferred to the batteries 31 and 32 via the circulation path 111. This allows the heat generated in the upper and lower arm switches SUH~SWL and the armature windings 11U, 11V, and 11W of each phase to be suitably used to raise the temperature of the batteries 31 and 32, enabling rapid heating of the batteries 31 and 32. Therefore, a configuration suitable for warming the batteries 31 and 32 can be realized by implementing temperature control.

[0090] <Second Embodiment> The second embodiment will be described below, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the d-axis current phase θd is a variable value that changes over time, instead of being a fixed value. By making the d-axis current phase θd a variable value, it becomes possible to control the amplitude of each phase current Iu, Iv, and Iw that flows during the temperature rise control.

[0091] The following explains the relationship between the d-axis current phase θd and the phase currents Iu, Iv, and Iw. When the currents Inr and Idr shown on the right-hand side of equations (eq1) and (eq2) flow, the phase currents Iu, Iv, and Iw are expressed as shown in equations (eq3), (eq4), and (eq5) below.

[0092]

number

[0093] Therefore, in this embodiment, the control device 50 performs temperature rise control in such a way that, in addition to the current and frequency conditions described in the first embodiment, it satisfies the phase difference condition that the d-axis current phase θd changes over time. In this case, it is possible to change the maximum phase among each phase in which the magnitude of the phase currents Iu, Iv, and Iw is maximum during the implementation of temperature rise control. As a result, it is possible to suppress uneven heat generation in the armature windings and upper and lower arm switches in any particular phase among each phase. As a result, it is possible to increase the amount of heat generated by implementing temperature rise control while suppressing excessive thermal stress on each phase armature winding 11U, 11V, 11W and each phase upper and lower arm switch SUH~SWL.

[0094] Specifically, in step S15 of Figure 6, the setting unit 60 sets the d-axis current phase θd of the d-axis command current Id* to a variable value that changes over time, instead of a predetermined value. For example, the setting unit 60 sets the d-axis current phase θd of the d-axis command current Id* to a variable value that changes periodically over time within the range of -π ≤ θd < π. Alternatively, for example, the setting unit 60 sets the d-axis current phase θd of the d-axis command current Id* to a variable value that changes discretely over time within the range of -π ≤ θd < π.

[0095] Figures 8 and 9 show an example of temperature rise control in which the d-axis current phase θd is varied over time. Note that in Figures 8 and 9, (a) to (f) correspond to Figures 7(a) to (f) above.

[0096] In Figure 8, the d-axis current phase θd of the d-axis command current Id* is set to a variable value that changes in a sawtooth wave pattern. The phase change period Tθ of the d-axis current phase θd is set to be longer than the periods Tn and Td of each command current In* and Id*. The d-axis current phase θd gradually increases within the phase change period Tθ. As shown in Figures 8(c) to (e), the amplitude of each phase current Iu, Iv, and Iw changes with the passage of time since the start of temperature rise control. Here, the change in amplitude of the U and W phase currents Iu and Iw is significant, and the maximum phase within the phase change period Tθ is the U phase or the W phase. In the maximum phase, the heat generation in the armature winding and the upper and lower arm switches is the greatest among all phases. Therefore, by changing the maximum phase within the phase change period Tθ, it is possible to suppress the amount of heat generated in one period of the phase change period Tθ from being biased towards a specific phase.

[0097] In Fig. 9, the d-axis current phase θd of the d-axis command current Id* is set to a variable value that changes in a stepwise manner. Letting the elapsed time since the start of the temperature rise control be t, when 0 ≦ t ≦ 0.3, the d-axis current phase θd = 0 [rad.]. In this case, the maximum phase is the U phase. When 0.3 < t ≦ 0.6, the d-axis current phase θd = -π [rad.]. In this case, the maximum phase is the W phase. When 0.6 ≦ t ≦ 0.8, the d-axis current phase θd = π / 4 [rad.]. In this case, the maximum phase is the U phase. Thus, each time a predetermined time elapses, the d-axis current phase θd is changed in a stepwise manner, whereby the maximum phase is changed. Thereby, it is possible to suppress the heat generation in the armature winding and the upper and lower arm switches from being biased to a specific phase.

[0098] <Modification Example of the Second Embodiment> · The setting unit 60 may set the d-axis current phase θd of the d-axis command current Id* to a variable value in a sawtooth wave shape, which is a variable value that gradually decreases within the phase change period Tθ. Further, the setting unit 60 may set the d-axis current phase θd of the d-axis command current Id* to a variable value in a waveform other than a sawtooth wave (for example, a triangular wave).

[0099] <Third Embodiment> Hereinafter, the third embodiment will be described with reference to the drawings, focusing on the differences from the second embodiment. In this embodiment, the phase difference condition is changed. Specifically, in addition to the current condition and the frequency condition described in the first embodiment, the control device 50 performs temperature rise control so as to satisfy the phase difference condition that the d-axis current phase θd is a specific value. Here, the specific value is a value at which the magnitudes of the phase currents in any two of the phases are equal.

[0100] Specifically, as the specific values, there are a first specific value θd1 at which the magnitudes of the U-phase current Iu and the V-phase current Iv are equal, a second specific value θd2 at which the magnitudes of the V-phase current Iv and the W-phase current Iw are equal, and a third specific value θd3 at which the magnitudes of the W-phase current Iw and the U-phase current Iu are equal. For example, the first specific value θd1 is a value that satisfies the following formulas (eq6) and (eq7).

[0101]

number

[0102]

number

[0103]

number

[0104]

number

[0105]

number

[0106]

number

[0107] Figures 10, 11, and 12 show examples of temperature rise control where the d-axis current phase θd is set to a specific value. In Figures 10, 11, and 12, (a) to (f) correspond to Figures 7(a) to (f) above. In Figure 10, the d-axis current phase θd is set to the first specific value θd1. In this case, the amplitudes |Iu| and |Iv| of the U and V phase currents Iu and Iv are aligned to 137[A]. In Figure 11, the d-axis current phase θd is set to the second specific value θd2. In this case, the amplitudes |Iv| and |Iw| of the V and W phase currents Iv and Iw are aligned to 195[A]. In Figure 12, the d-axis current phase θd is set to the third specific value θd3. In this case, the amplitudes |Iu| and |Iw| of the U and W phase currents Iu and Iw are aligned between 326[A] and 327[A].

[0108] In temperature rise control, when the phase difference condition—that the d-axis current phase θd is a specific value—is met in addition to the current and frequency conditions, the armature windings and upper and lower arm switches can be heated evenly in two of the phases. This prevents the amount of heat generated by temperature rise control from being limited due to heat concentration in one of the specific phases. As a result, the amount of heat generated by temperature rise control can be accurately increased.

[0109] In this embodiment, the setting unit 60 selects from the specified values ​​θd1, θd2, θd3 the value in which the magnitudes of each phase current Iu, Iv, and Iw flowing during temperature rise control are closest to each other, and sets the d-axis current phase θd to the selected specified value. In this case, the setting unit 60 calculates the amplitudes |Iu|, |Iv|, and |Iw| of each phase current Iu, Iv, and Iw that flow when the d-axis current phase θd = θd1, θd2, and θd3. For example, the setting unit 60 calculates the amplitudes |Iu|, |Iv|, and |Iw| of each phase current Iu, Iv, and Iw based on the amplitudes Ina, Ina of each command current In* and Id* set in the processing of steps S12 and S14 in Figure 6 above, and the above equations (eq8), (eq9), (eq12), (eq13), (eq16), and (eq17). Based on the calculated amplitudes |Iu|, |Iv|, and |Iw|, the setting unit 60 selects the value from each specific value θd1, θd2, and θd3 that is closest to the magnitudes of each phase current Iu, Iv, and Iw.

[0110] For example, assuming a situation where temperature rise control is performed under the control conditions shown in Figures 10-12, when the d-axis current phase θd = θd1, the difference between the amplitude |Iw| of the W-phase current Iw and the amplitudes |Iu|, |Iv| of the U,V-phase currents Iu, Iv is 317 [A] (see Figure 10). When the d-axis current phase θd = θd2, the difference between the amplitude |Iu| of the U-phase current Iu and the amplitudes |Iv|, |Iw| of the V,W-phase currents Iv, Iw is 214 [A] (see Figure 11). When the d-axis current phase θd = θd3, the difference between the amplitude |Iv| of the V-phase current Iv and the amplitudes |Iu|, |Iw| of the U,W-phase currents Iu, Iw is 153 [A] (see Figure 12). In this case, the setting unit 60 selects the third specific value θd3 from among the specific values ​​θd1, θd2, and θd3, as the value in which the magnitudes of the phase currents Iu, Iv, and Iw that flow during the temperature rise control are closest to each other.

[0111] In this embodiment, among the specific values ​​θd1, θd2, and θd3, the value in which the magnitudes of the phase currents Iu, Iv, and Iw flowing during temperature rise control are closest to each other is set as the d-axis current phase θd. This allows the armature windings and upper and lower arm switches to generate heat as evenly as possible in each phase. Therefore, the amount of heat generated in each phase armature winding 11U, 11V, and 11W and each phase upper and lower arm switch SUH to SWL can be accurately equalized.

[0112] <Modified form of the third embodiment> The setting unit 60 may change the d-axis current phase θd over time when setting the d-axis current phase θd to one of the specific values ​​θd1, θd2, and θd3. For example, as shown in Figure 13, the setting unit 60 may change the d-axis current phase θd in the order of the first specific value θd1, the second specific value θd2, and the third specific value θd3. This helps to equalize the amount of heat generated in each phase armature winding 11U, 11V, 11W and each phase upper and lower arm switch SUH~SWL, while suppressing the uneven distribution of heat generation in the armature winding and upper and lower arm switches to a specific phase, thereby preventing excessive thermal stress.

[0113] According to equations (eq7), (eq11), and (eq15) above, the maximum value of the amplitude Ida of the d-axis command current Id* changes depending on the electrical angle θe. Figure 14 shows the relationship between the maximum value of the current ratio Ida / Ina and the electrical angle θe for each of the d-axis current phases θd = θd1, θd2, and θd3. As shown in Figure 14, for the same electrical angle θe, the maximum value of the current ratio Ida / Ina is different for each of the d-axis current phases θd = θd1, θd2, and θd3. For example, in the region 0 ≤ θe ≤ π / 3, the maximum value of the current ratio Ida / Ina is larger when the d-axis current phase is θd = θd3 than when the d-axis current phase is θd = θd1 or θd2. In order to set the amplitude Ida of the d-axis command current Id* to the largest possible value, it is desirable to select the specific value θd1, θd2, and θd3 that has the largest maximum value of the current ratio Ida / Ina as the d-axis current phase θd.

[0114] Therefore, the setting unit 60 may set the d-axis current phase θd to one of the specific values ​​θd1, θd2, or θd3 based on the current electrical angle θe. In other words, the setting unit 60 may select two phases from among the phases that have the same phase current magnitude based on the current electrical angle θe. The setting unit 60 can use the value detected by the rotation angle sensor 87 as the current electrical angle θe.

[0115] In this embodiment, the setting unit 60 sets the d-axis current phase θd = θd3 in the regions 0 ≤ θe ≤ π / 3 and π < θe ≤ 4π / 3. The setting unit 60 sets the d-axis current phase θd = θd2 in the regions π / 3 < θe ≤ 2π / 3 and 4π / 3 < θe ≤ 5π / 3. The setting unit 60 sets the d-axis current phase θd = θd1 in the regions 2π / 3 < θe ≤ π and 5π / 3 < θe < 2π.

[0116] By using a value selected from the specific values ​​θd1, θd2, and θd3 based on the electrical angle θe as the d-axis current phase θd, it becomes possible to set a large value for the amplitude Ida of the d-axis command current Id*. As a result, a configuration suitable for increasing the amount of heat generated by temperature rise control can be realized.

[0117] The setting unit 60 does not need to perform the process of selecting the value among the specific values ​​θd1, θd2, and θd3 that brings the magnitudes of the phase currents Iu, Iv, and Iw flowing during temperature rise control closest to each other. For example, the setting unit 60 may set a predetermined value among the specific values ​​θd1, θd2, and θd3 as the d-axis current phase θd.

[0118] <Fourth Embodiment> The fourth embodiment will be described below, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the frequency conditions have been changed.

[0119] The control device 50 performs temperature rise control to satisfy the frequency condition that, in addition to the current conditions described in the first embodiment, a d-axis current Idr with a frequency different from the frequency fn of the path current Inr flows. In this case, in steps S11 and S13 of Figure 6, the setting unit 60 sets the angular frequency ωn of the path command current In* and the angular frequency ωd of the d-axis command current Id* to different values. When the angular frequencies ωn and ωd of the respective command currents In* and Id* are set to different values, the respective phase currents Iu, Iv, and Iw that flow during the temperature rise control are expressed as shown in the following equations (eq18), (eq19), and (eq20).

[0120]

number

[0121]

number

[0122]

number

[0123] For example, by allowing the frequency fd of the d-axis current Idr to be set to a different value from the frequency fn of the path current Inr, it becomes possible to improve the NV characteristics (i.e., noise and vibration characteristics) during temperature rise control without reducing the amplitudes Ina and Ida. Therefore, it is possible to improve the NV characteristics while maintaining the amount of heat generated during temperature rise control.

[0124] Furthermore, for example, by allowing the frequency fd of the d-axis current Idr to be set to a different value from the frequency fn of the path current Inr, it becomes possible to control the peak values ​​of each phase current Iu, Iv, and Iw. In the example shown in Figure 15, the angular frequency ωn of the path command current In* is set to 100 [Hz], and the angular frequency ωd of the d-axis command current Id* is set to 300 [Hz]. In this case, the peak value of the V-phase current Iv is reduced compared to the peak values ​​of the U and W-phase currents Iu and Iw. Note that in Figure 15, (a) to (f) correspond to Figures 7(a) to (f) above.

[0125] <Modified form of the fourth embodiment> The angular frequency ωd of the d-axis command current Id* is not limited to being set to 3 times or 1 / 3 times the angular frequency ωn of the path command current In*. For example, in step S13 of Figure 6, the setting unit 60 may set the angular frequency ωd of the d-axis command current Id* to 5 times, 7 times, 1 / 5 times, or 1 / 7 times the angular frequency ωn of the path command current In*.

[0126] In step S15 of Figure 6, the setting unit 60 may set the d-axis current phase θd of the d-axis command current Id* to a value other than 0 within the range of 0 ≤ θe < 2π.

[0127] <Fifth Embodiment> The fifth embodiment will be described below, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the temperature rise control procedure has been modified.

[0128] Figure 16 shows the processing procedure for temperature rise control performed by the control device 50. This control is performed repeatedly, for example, at a predetermined control cycle.

[0129] After the processing in step S12, the process proceeds to step S20. In step S20, the setting unit 60 calculates the amount of heat generated Qn that would occur if switching control were performed during the heating time according to the control conditions set in steps S11 and S12. In other words, it calculates the amount of heat generated Qn that would occur if switching control were performed during the heating time so that only the AC path current Inr flows among the currents Inr and Idr. For example, the amount of heat generated in each battery 31 and 32 is calculated using correspondence information that associates the amount of heat generated Qn with the internal resistance values ​​of each battery 31 and 32, the resistance values ​​of each phase armature winding 11U, 11V, and 11W, the resistance values ​​of each switch SUH to SWL (e.g., on-resistance values), the amplitude Ina of the path command current In*, and the angular frequency ωn of the path command current In*. The correspondence information is map information or mathematical formula information. The internal resistance values ​​of each battery 31 and 32 may be predetermined values ​​or values ​​calculated based on the battery temperature. Furthermore, when calculating the amount of heat generated Qn, the heat transfer efficiency from each winding 11U, 11V, 11W and each switch SUH~SWL to each storage battery 31, 32 via the circulation path 111 may also be considered.

[0130] In step S21, the setting unit 60 determines whether the calculated heat generation amount Qn is insufficient compared to the required value. For example, the required value is the amount of heat required to raise the battery temperature from the current value to the target value. The required value is notified by the higher-level control device.

[0131] If a positive determination is made in step S21, the process proceeds to step S13. In this case, temperature control is performed to satisfy the first current condition, which is that the AC path current Inr flows and the AC d-axis current Idr flows. On the other hand, if a negative determination is made in step S21, the process proceeds to step S22. In step S22, the setting unit 60 sets the d-axis command current Id* to 0. After the processing in step S22, the process proceeds to step S16. In this case, temperature control is performed to satisfy the second current condition, which is that of the currents Inr and Idr, only the AC path current Inr flows. Note that the processing in steps S20 and S21 corresponds to the "determination unit".

[0132] In this embodiment, it is determined whether the amount of heat generated Qn, which is generated when the temperature rise control is performed to satisfy the second current condition, is insufficient compared to the required value. If it is determined that the amount of heat generated Qn is insufficient compared to the required value, the temperature rise control is performed to satisfy the first current condition. On the other hand, if it is determined that the amount of heat generated Qn is sufficient compared to the required value, the temperature rise control is performed to satisfy the second current condition. In other words, when it is possible to satisfy the temperature rise requirement of each battery 31, 32 by having only the AC path current Inr flow among the currents Inr and Idr, the d-axis current Idr, which promotes heat generation in each winding 11U, 11V, 11W and each switch SUH~SWL, is not flowed. This suppresses the deterioration of the efficiency of the temperature rise control caused by the heat generated when the windings 11U, 11V, 11W and each switch SUH~SWL are energized being transmitted to each battery 31, 32 via the circulation path 111. Here, the efficiency of the temperature rise control is the ratio of the temperature rise of each battery 31, 32 to the power consumption of each battery 31, 32. According to the embodiment described above, a configuration suitable for improving the efficiency of temperature rise control can be realized.

[0133] <Other Embodiments> Furthermore, each of the above embodiments may be implemented with the following modifications.

[0134] In step S15 of Figure 6, 16, the setting unit 60 may set the d-axis current phase θd of the d-axis command current Id* based on at least one of the temperatures of each phase armature winding 11U, 11V, 11W and each switch SUH to SWL. The detected value Tmw from the motor temperature sensor 90 can be used as the temperature of each phase armature winding 11U, 11V, 11W. The detected value Tms from the switch temperature sensor 89 can be used as the temperature of each switch SUH to SWL.

[0135] According to this embodiment, it is possible to set the d-axis current phase θd so as to avoid the temperatures of each phase armature winding 11U, 11V, 11W and each phase upper and lower arm switches SUH to SWL from becoming excessively high. Therefore, while suppressing excessive thermal stress from being applied to each phase armature winding 11U, 11V, 11W and each phase upper and lower arm switches SUH to SWL, the amount of heat generated by implementing the temperature rise control can be increased.

[0136] · In the first embodiment, in addition to the current condition, the temperature rise control may be performed so as to satisfy the frequency condition that the frequency fd of the d-axis current Idr is a value obtained by multiplying the frequency fn of the path current Inr by a predetermined constant K. For example, the constant K is a value in the range of 0.95 ≦ K < 1.00 or 1.00 < K ≦ 1.05. That is, the frequency condition may be a condition that a d-axis current Idr having the same frequency as the frequency fn of the path current Inr flows. Even in this case, simplification of the control design of the temperature rise control can be achieved.

[0137] · The setting unit 60 is not limited to setting the q-axis command current Iq* to 0. The setting unit 60 may set the q-axis command current Iq* to a value other than 0 within a range where the stopped state of the vehicle can be maintained. Even in this case, it is possible to perform the temperature rise control so as to satisfy the current condition.

[0138] · The control device 50 may perform the temperature rise control so as to satisfy the current condition while performing the drive control in a state where each main switch SMRH, SMRL and each motor side switch 71, 72 are turned on and the precharge switch SMRP and each connection switch DCRH, DCRL are turned off. That is, during the running of the vehicle, the temperature rise control that satisfies the current condition may be performed.

[0139] In this embodiment, the setting unit 60 shown in Figure 4 receives a torque command value from a higher-level control device. Based on the input torque command value, the setting unit 60 sets the DC q-axis command current Iq*. If the setting unit 60 determines that there is a temperature increase request, it sets the AC path command current In*, as described in the first embodiment. Based on the input torque command value and the temperature increase request, the setting unit 60 sets the d-axis command current Id*. In this case, the waveform of the d-axis command current Id* is, for example, a waveform in which a sine wave is offset to the positive or negative side.

[0140] The setting unit 60 may, instead of setting the d-axis current phase θd, set the phase difference between the path command current In* and the d-axis command current Id*. In this case as well, it is possible to perform temperature rise control similar to the control described in each of the above embodiments.

[0141] The target of the temperature increase control may be, for example, the cooling water in the circulation path 111. In this case, the temperature of the heat source of the heating device 115 can be rapidly increased by implementing the temperature increase control. In this embodiment, the control device 50 determines that there is a request for a temperature increase when, for example, it determines that the detected value of the cooling water temperature sensor (not shown) is below the target value.

[0142] The neutral point capacitor may connect the high-potential side path 22H and the connection path 73. For example, as shown in Figure 17, the first end of the neutral point capacitor 75 may be connected to the portion of the high-potential side path 22H that is closer to the inverter 20 than the high-potential side main switch SMRH. The second end of the neutral point capacitor 75 may be connected to the portion of the connection path 73 that is between the first motor side switch 71 and the second motor side switch 72.

[0143] The switch for inverter 20 is not limited to IGBTs; for example, an N-channel MOSFET equipped with a body diode may also be used. In this case, the high-potential terminal of the N-channel MOSFET becomes the drain, and the low-potential terminal becomes the source.

[0144] • A high-potential side main switch SMRH does not necessarily need to be provided.

[0145] Instead of the low-potential main switch SMRL, the high-potential main switch SMRH may be connected in parallel to the pre-charge switch SMRP and the pre-charge resistor 40 in series. In this case, the low-potential main switch SMRL may not be provided.

[0146] The rotating electric machine and inverter are not limited to 3-phase machines, but may also be 2-phase or 4-phase or more. Furthermore, the rotating electric machine is not limited to a permanent magnet type synchronous machine having permanent magnets as field poles in the rotor, but may also be a wound-field type synchronous machine having field windings as field poles in the rotor. In this case, the rotor may be equipped with both field windings and permanent magnets. Furthermore, the rotating electric machine is not limited to a synchronous machine, but may also be an induction machine.

[0147] The energy storage unit is not limited to a battery; for example, it may include a large-capacity electric double-layer capacitor, or both a battery and an electric double-layer capacitor.

[0148] The mobile body on which the power conversion system is installed is not limited to a vehicle; for example, it could be an aircraft or a ship. Furthermore, the location on which the power conversion device is installed is not limited to a mobile body; it could be a stationary device.

[0149] The control devices and methods described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control devices and methods described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control devices and methods described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium. [Explanation of Symbols]

[0150] 10... Rotating electric machine, 20... Inverter, 22H... High potential side path, 22L... Low potential side path, 31, 32... First and second storage batteries, 50... Control device, 68... Command generation unit, 69... Switch control unit, 73... Connection path.

Claims

1. A rotating electric machine (10) having multiple phase armature windings (11U, 11V, 11W), An inverter (20) having upper arm switches (SUH, SVH, SWH) and lower arm switches (SUL, SVL, SWL) for each phase, wherein in each phase, the low-potential terminal of the upper arm switch and the high-potential terminal of the lower arm switch are electrically connected to the armature winding, In a control device (50) applied to a system (100) comprising, The aforementioned system, A high-potential side path (22H) electrically connects the positive terminal of the first energy storage unit (31) and the high-potential side terminal of the upper arm switch, A low-potential side path (22L) electrically connects the negative terminal of the second energy storage unit (32) and the low-potential side terminal of the lower arm switch, A connection path (73) electrically connects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit to the neutral point (O) of the star-connected armature winding, Equipped with, A command generation unit (68) that generates drive commands for the upper arm switch and the lower arm switch, A switch control unit (69) performs switching control of the upper arm switch and the lower arm switch based on the drive command generated by the command generation unit, Equipped with, The command generation unit is a control device that generates the drive command such that it satisfies the current conditions that an alternating current path current flows through the connection path and an alternating current d-axis current flows through the armature windings of each phase.

2. The control device according to claim 1, wherein the command generation unit generates the drive command such that, in addition to the current condition, the d-axis current flows at a frequency equivalent to the frequency of the path current.

3. The control device according to claim 2, wherein the command generation unit generates the drive command such that, in addition to the current condition and the frequency condition, it satisfies the phase difference condition that the phase difference between the path current and the d-axis current changes over time.

4. The command generation unit generates the drive command such that, in addition to the current condition and the frequency condition, it satisfies the phase difference condition that the phase difference between the path current and the d-axis current is a specific value. The control device according to claim 2, wherein the specified value is a value that equalizes the magnitude of the phase currents in any two of the phases.

5. The aforementioned rotating electric machine is a three-phase machine. The control device according to claim 4, wherein the specified value is the value among a first specified value in which the magnitudes of the U-phase current and the V-phase current are the same, a second specified value in which the magnitudes of the V-phase current and the W-phase current are the same, and a third specified value in which the magnitudes of the W-phase current and the U-phase current are the same, the value in which the magnitudes of each phase current flowing during the execution of the switching control are closest to each other.

6. The aforementioned rotating electric machine is a three-phase machine. The specified values ​​are a first specified value in which the magnitudes of the U-phase current and the V-phase current are the same, a second specified value in which the magnitudes of the V-phase current and the W-phase current are the same, and a third specified value in which the magnitudes of the W-phase current and the U-phase current are the same. The control device according to claim 4, wherein the phase difference condition is that the phase difference is one of the first specific value, the second specific value, and the third specific value, and that the phase difference changes over time.

7. The aforementioned rotating electric machine is a three-phase machine. The control device according to claim 4, wherein the command generation unit selects one of the following as the specified value based on the electrical angle of the rotor of the rotating electric machine: a first specified value in which the magnitudes of the U-phase current and the V-phase current are the same; a second specified value in which the magnitudes of the V-phase current and the W-phase current are the same; and a third specified value in which the magnitudes of the W-phase current and the U-phase current are the same; and generates the drive command such that the phase difference condition is satisfied, where the phase difference is the selected specified value.

8. The control device according to claim 1, wherein the command generation unit generates the drive command such that the d-axis current flows at a frequency different from the frequency of the path current, satisfying the frequency condition.

9. The control device according to any one of claims 1 to 8, wherein the system comprises a heat transfer unit (111) that transfers heat generated in the armature winding, the upper arm switch, and the lower arm switch to the first energy storage unit and the second energy storage unit.

10. The aforementioned current condition is the first current condition, The condition that only the path current flows among the path current and the d-axis current is defined as the second current condition. The system includes a determination unit that determines whether the amount of heat generated when the switching control is performed to satisfy the second current condition is insufficient to meet the required value for the temperature rise of the first and second energy storage units. The command generation unit, If the determination unit determines that the heat quantity is insufficient to meet the required value, the drive command is generated to satisfy the first current condition. The control device according to claim 9, wherein the determination unit determines that the amount of heat is not insufficient to the required value, and generates the drive command to satisfy the second current condition.

11. A rotating electric machine (10) having multiple phase armature windings (11U, 11V, 11W), An inverter (20) having upper arm switches (SUH, SVH, SWH) and lower arm switches (SUL, SVL, SWL) for each phase, wherein in each phase, the low-potential terminal of the upper arm switch and the high-potential terminal of the lower arm switch are electrically connected to the armature winding, In a program applied to a system (100) comprising the following: The aforementioned system, A high-potential side path (22H) electrically connects the positive terminal of the first energy storage unit (31) and the high-potential side terminal of the upper arm switch, A low-potential side path (22L) electrically connects the negative terminal of the second energy storage unit (32) and the low-potential side terminal of the lower arm switch, A connection path (73) electrically connects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit to the neutral point (O) of the star-connected armature winding, Equipped with, The processor (51) A command generation process that generates drive commands for the upper arm switch and the lower arm switch, A switch control process that controls the switching of the upper arm switch and the lower arm switch based on the drive command generated by the command generation process, Make it run, The command generation process includes a program that generates the drive command such that it satisfies the current conditions that an alternating current path current flows through the connection path and an alternating current d-axis current flows through the armature windings of each phase.

12. A rotating electric machine (10) having multiple phase armature windings (11U, 11V, 11W), An inverter (20) having upper arm switches (SUH, SVH, SWH) and lower arm switches (SUL, SVL, SWL) for each phase, wherein in each phase, the low-potential terminal of the upper arm switch and the high-potential terminal of the lower arm switch are electrically connected to the armature winding, In a control method applied to a system (100) comprising the following: The aforementioned system, A high-potential side path (22H) electrically connects the positive terminal of the first energy storage unit (31) and the high-potential side terminal of the upper arm switch, A low-potential side path (22L) electrically connects the negative terminal of the second energy storage unit (32) and the low-potential side terminal of the lower arm switch, A connection path (73) electrically connects the negative terminal of the first energy storage unit and the positive terminal of the second energy storage unit to the neutral point (O) of the star-connected armature winding, Equipped with, A command generation step for generating drive commands for the upper arm switch and the lower arm switch, A switch control step that performs switching control of the upper arm switch and the lower arm switch based on the drive command generated in the command generation step, Includes, A control method comprising the command generation step, which generates the drive command such that the current conditions are satisfied, namely that an alternating current path current flows through the connection path and an alternating current d-axis current flows through the armature windings of each phase.

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