Vehicle drive control device and control method for vehicle drive control device

Abstract

To suppress overcurrent of switching elements that configure a motor driver.SOLUTION: A vehicle drive control device 100 comprises a motor driver 14, a contactor 12, a capacitor 13, and a control device 3. The control device 3 comprises: a voltage acquisition unit 311 that acquires a capacitor voltage VC; a current acquisition unit 312 that acquires a current value IU, a current value IV, and a current value IW flowing in respective coils of a motor 15; an angle acquisition unit 313 that acquires a rotation angle θ of the motor 15; an axis current calculation unit 314 that calculates a q-axis current value IQ and a d-axis current value ID from the current value IU, the current value IV, the current value IW, and the rotation angle θ; and a voltage control unit 315 that, when the contactor 12 is in an OFF state, controls a q-axis current JQ to hold the capacitor voltage VC at a value equal to or less than a predetermined voltage.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vehicle drive control device and a control method for a vehicle drive control device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a technique relating to a vehicle drive control device that is mounted on a vehicle and driven by a motor. For example, Patent Document 1 describes a motor driver that short-circuits the AC output terminals of the motor driver (inverter) when an abnormality occurs. It also discloses that when the contactor is turned off while the motor is being driven, if the motor induced voltage rises, various components such as the control circuit are activated to perform control so that the withstand voltage is not exceeded. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-183702 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when an abnormality occurs in the vehicle and the AC output terminal of the motor driver is shorted, a large motor current may be generated depending on the type of motor, so it is necessary to suppress the overcurrent in order to prevent damage to the switching elements that make up the motor driver. An object of the present invention is to suppress overcurrent in a switching element that constitutes a motor driver. [Means for solving the problem]

[0005] One aspect of the present invention includes a motor driver configured with switching elements and controlling a motor that drives a vehicle, a switch arranged between a power source and the motor driver, a capacitor arranged between a positive terminal and a negative terminal of the motor driver, and a control device that controls the motor driver, wherein the control device includes an acquisition unit that acquires the capacitor voltage, a current acquisition unit that acquires a current value flowing through each coil of the motor, an angle acquisition unit that acquires a rotation angle of the motor, an axis current calculation unit that calculates a q-axis current value and a d-axis current value from the current value and the rotation angle, and a voltage control unit that controls the q-axis current to maintain the capacitor voltage at or below a predetermined voltage when the switch is off. The predetermined voltage is set to a value smaller than the withstand voltage of the switching element. A vehicle drive control device. [Effects of the Invention]

[0006] According to the present invention, it is possible to suppress overcurrent in a switching element that constitutes a motor driver. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a vehicle drive control device. [Figure 2] FIG. 2 is a diagram showing an example of the configuration of a control device. [Figure 3] FIG. 2 is a diagram showing an example of the configuration of a voltage control circuit. [Figure 4] 10 is a graph showing an example of a capacitor voltage. [Figure 5] 10 is a flowchart showing an example of processing by a control device. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] [1. Configuration of vehicle drive control device] First, the configuration of the vehicle drive control device 100 will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of the vehicle drive control device 100. As shown in FIG. 1, the vehicle drive control device 100 includes a motor drive circuit 1, a driver drive circuit 2, and a control device 3. The motor drive circuit 1 is a circuit for driving a motor 15, and includes a battery 11, a contactor 12, a capacitor 13, and a motor driver .

[0010] The battery 11 supplies power to the motor 15 via the motor driver 14 . The battery 11 corresponds to an example of a "power source." The contactor 12 is disposed between the battery 11 and the motor driver 14. The contactor 12 is turned off when an abnormality occurs in the vehicle. When the contactor 12 is turned off, the supply of power from the battery 11 to the motor driver 14 is cut off. The contactor 12 corresponds to an example of a "switch."

[0011] Capacitor 13 is disposed between positive terminal 14P and negative terminal 14M of motor driver 14. Capacitor 13 applies a capacitor voltage VC between positive terminal 14P and negative terminal 14M of motor driver 14, and capacitor voltage VC is detected by voltage sensor SV.

[0012] When the contactor 12 is turned off, in order to power the motor 15, that is, to drive the motor 15, power is supplied from the capacitor 13 to the motor 15 via the motor driver 14. In this case, the capacitor voltage VC drops. Furthermore, when the contactor 12 is turned off and the motor 15 is in a regenerative operation, power is regenerated from the motor 15 to the capacitor 13 via the motor driver 14. In this case, the capacitor voltage VC increases.

[0013] The motor driver 14 is configured with MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors) 14U1, 14U2, 14V1, 14V2, 14W1, and 14W2. Each of these six MOSFETs is turned on and off based on an instruction from the driver driving circuit 2. The MOSFET corresponds to an example of a "switching element."

[0014] The motor 15 is, for example, a three-phase synchronous motor using a permanent magnet. As shown in Fig. 1, the motor 15 includes a motor coil 15U, a motor coil 15V, and a motor coil 15W. The motor 15 drives the vehicle with power supplied from the battery 11 via the motor driver 14. The vehicle is, for example, a motorbike (motorcycle).

[0015] In this embodiment, the vehicle is described as a motorbike (two-wheeled motor vehicle), but is not limited to this. The vehicle may be, for example, a four-wheeled passenger car or a four-wheeled large vehicle. The vehicle may also be, for example, a work vehicle such as a tractor.

[0016] A voltage sensor SV is disposed on the capacitor 13. The voltage sensor SV detects a capacitor voltage VC, which is the voltage across the capacitor 13. The voltage sensor SV outputs the detected capacitor voltage VC to the control device 3.

[0017] A current sensor SC is disposed between the motor driver 14 and the motor 15. The current sensor SC detects the value of a current flowing through each coil of the motor 15. That is, the current sensor SC detects the current value IU flowing through the motor coil 15U, the current value IV flowing through the motor coil 15V, and the current value IW flowing through the motor coil 15W. The current sensor SC outputs the detected current values ​​IU, IV, and IW to the control device 3. The location of the current sensor SC is not limited to this. The current sensor SC may also be disposed in the lower MOSFET.

[0018] An angle sensor SA is provided on the motor 15. The angle sensor SA is configured with a so-called resolver, a Hall element, or the like, and detects the rotation angle θ and rotation angular velocity ω of the motor 15. The angle sensor SA outputs the detected rotation angle θ and rotation angular velocity ω to the control device 3.

[0019] The driver drive circuit 2 controls the motor driver 14 in accordance with instructions from the control device 3. That is, the driver drive circuit 2 controls the on / off of each of the six MOSFETs that make up the motor driver 14 in accordance with instructions from the control device 3.

[0020] The control device 3 controls the driver circuit 2 based on the capacitor voltage VC, the current values ​​IU, IV, and IW, the rotation angle θ, and the rotation angular velocity ω. When the contactor 12 is off, the control device 3, for example, performs field-weakening control on the motor 15. This field-weakening control may be started when the contactor 12 is on and may continue even after the contactor 12 changes to the off state. The control device 3 also controls the motor 15, for example, to maintain the capacitor voltage VC at or below a predetermined voltage. The predetermined voltage is set to a value smaller than the withstand voltage VCM of the MOSFET that constitutes the motor driver 14. The control device 3 will be further described with reference to FIGS.

[0021] [2. Control device configuration] Next, the configuration of the control device 3 will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the configuration of the control device 3. The control device 3 controls the motor 15 via the driver driving circuit 2 and the motor driver 14 based on the detection results of the voltage sensor SV, the current sensor SC, and the angle sensor SA. The control device 3 is configured by, for example, an ECU (Electronic Control Unit). The control device 3 includes a processor 31, a memory 32, and a voltage control circuit 33. When the contactor 12 is off, the voltage control circuit 33 controls the q-axis current value IQ so that the capacitor voltage VC becomes the target voltage VCA. The voltage control circuit 33 constitutes a part of the "voltage control section." Voltage control circuit 33 is further described with reference to FIG.

[0022] The memory 32 is a storage device that non-volatilely stores programs and data executed by the processor 31. The memory 32 is configured by a semiconductor storage element such as a magnetic storage device or a flash ROM (Read Only Memory), or other types of non-volatile storage device. The memory 32 may also include a RAM (Random Access Memory) that configures the work area of ​​the processor 31. The memory 32 stores data processed by the control device 3 and a control program 321 executed by the processor 31.

[0023] The processor 31 may be configured as a single processor, or multiple processors may function as the processor 31. The processor 31 executes a control program 321 to control the motor 15 via the driver driving circuit 2 and the motor driver 14. The control device 3 includes a voltage acquisition unit 311, a current acquisition unit 312, an angle acquisition unit 313, an axial current calculation unit 314, and a voltage control unit 315. Specifically, the processor 31 of the control device 3 executes a control program 321 to function as the voltage acquisition unit 311, the current acquisition unit 312, the angle acquisition unit 313, the axial current calculation unit 314, and the voltage control unit 315.

[0024] The voltage acquisition unit 311 acquires the capacitor voltage VC from the voltage sensor SV. The capacitor voltage VC is the voltage across the capacitor 13.

[0025] The current acquisition unit 312 acquires the current values ​​IU, IV, and IW from the current sensor SC. The current value IU is the value of the current flowing through the motor coil 15U. The current value IV is the value of the current flowing through the motor coil 15V. The current value IW is the value of the current flowing through the motor coil 15W.

[0026] The angle acquisition unit 313 acquires the rotation angle θ and the rotation angular velocity ω from the angle sensor SA. The rotation angle θ is the rotation angle of the motor 15, and the rotation angular velocity ω is the rotation angular velocity of the motor 15. In this embodiment, a case will be described in which the angle acquisition unit 313 acquires the rotation angle θ and the rotation angular velocity ω from the angle sensor SA, but this is not limiting. For example, the angle acquisition unit 313 may acquire the rotation angle θ from the angle sensor SA and calculate the rotation angular velocity ω from the rotation angle θ.

[0027] The axis current calculation unit 314 calculates the q-axis current value IQ and the d-axis current value ID from the current values ​​IU, IV, IW and the rotation angle θ. The axis current calculation unit 314 calculates the q-axis current value IQ by, for example, the following equation (1). IQ=[cos(θD)×IU+cos(θD-2π / 3)×IV +cos(θD+2π / 3)×IW]×(2 / 3) 1 / 2 (1) The rotation angle θD is calculated using the following equation (2). θD=θ×NP / 2 (2) Here, the pole number NP is the number of poles of the rotor. Further, the d-axis current calculation unit 314 calculates the d-axis current value ID by, for example, the following equation (3). ID=[-sin(θD)×IU-sin(θD-2π / 3)×IV -sin(θD+2π / 3)×IW]×(2 / 3) 1 / 2 (3)

[0028] When the contactor 12 is off, the voltage control unit 315 controls the q-axis current JQ to maintain the capacitor voltage VC at or below a predetermined voltage. In this embodiment, the voltage control unit 315 uses the voltage control circuit 33 to control the q-axis current JQ to maintain the capacitor voltage VC at or below the predetermined voltage.

[0029] For example, when the capacitor voltage VC is greater than the target voltage VCA, the voltage control unit 315 controls the q-axis current JQ in a direction that increases the running power using the voltage control circuit 33. Also, for example, when the capacitor voltage VC is smaller than the target voltage VCA, the voltage control unit 315 controls the q-axis current JQ in a direction that increases the regenerative power using the voltage control circuit 33. By controlling the q-axis current JQ in a direction that increases the running power, power is consumed by the motor 15, and the capacitor voltage VC decreases. By controlling the q-axis current JQ in a direction that increases the regenerative power, the power generated by the motor 15 is regenerated in the capacitor 13, and the capacitor voltage VC increases. In this way, the capacitor voltage VC can be maintained at a predetermined voltage or less.

[0030] The target voltage VCA is set to a value less than the withstand voltage VCM of the MOSFET that constitutes the motor driver 14 and equal to or greater than a voltage value at which field-weakening control of the motor 15 can be performed. Since the target voltage VCA is set to a voltage value that is equal to or greater than the voltage value that allows field-weakening control of the motor 15, it is possible to perform field-weakening control of the motor 15. Therefore, it is possible to prevent the capacitor voltage VC from becoming excessive, and therefore possible to suppress overcurrent in the MOSFET.

[0031] Furthermore, the voltage control unit 315 sets the d-axis current JD and the q-axis current JQ to zero when the rotation speed of the motor 15 becomes equal to or less than a threshold value. For example, when the rotation speed of the motor 15 becomes equal to or less than a threshold value, the voltage control unit 315 causes the driver drive circuit 2 to control the motor driver 14 so that the d-axis current JD and the q-axis current JQ become zero. The rotation speed of the motor 15 is calculated, for example, from the rotation angular velocity ω. When the rotation speed of the motor 15 falls below a threshold, the d-axis current JD and the q-axis current JQ are set to zero, so the torque generated by the motor 15 can be set to approximately zero (for example, below a predetermined value), allowing the user to easily stop the vehicle.

[0032] [3. Configuration of voltage control circuit] Next, the configuration of the voltage control circuit 33 will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of the voltage control circuit. 3, the voltage control circuit 33 constitutes a part of a feedback control system. The voltage control circuit 33 includes a differentiator 331 and a PID controller 332.

[0033] A differentiator 331 calculates a difference ΔVC between the target voltage VCA and the capacitor voltage VC. The target voltage VCA is set by the voltage control unit 315. The capacitor voltage VC is input from the voltage sensor SV. The PID controller 332 receives the difference ΔVC and outputs a target value IQA of the q-axis current JQ to the driver drive circuit 2. The PID controller 332 includes a P controller, an I controller, and a D controller. A P gain GP is set in the P controller, an I gain GI is set in the I controller, and a D gain GD is set in the D controller. The P controller outputs a value obtained by multiplying the P gain GP and the difference ΔVC. The I controller outputs a value obtained by multiplying the I gain GI and the time integral value of the difference ΔVC. The D controller outputs a value obtained by multiplying the D gain GD and the time derivative value of the difference ΔVC. The PID controller 332 outputs the sum of the outputs from the P controller, I controller, and D controller as the target value IQA.

[0034] The driver drive circuit 2 controls the motor driver 14 so that the q-axis current JQ becomes the target value IQA. The motor 15 operates according to the control of the motor driver 14. The amount of charge stored in the capacitor 13 changes in accordance with the operation of the motor 15, and the capacitor voltage VC changes. The voltage sensor SV detects the capacitor voltage VC, and the detected voltage is input to a differentiator 331.

[0035] In this way, by setting appropriate values ​​for the P gain GP, ​​the I gain GI, and the D gain GD in the PID controller 332, the feedback control system shown in FIG. 3 operates so that the capacitor voltage VC converges to the target voltage VCA.

[0036] In this embodiment, a case will be described in which the PID controller 332 performs PID control, but the present invention is not limited to this. The PID controller 332 may perform at least I control. For example, the PID controller 332 may perform PI control, or the PID controller 332 may perform ID control.

[0037] [4. Capacitor voltage] Next, an example of the change in the capacitor voltage VC controlled by the voltage control section 315 will be described with reference to Fig. 4. Fig. 4 is a graph showing an example of the capacitor voltage VC. 4, the horizontal axis represents time T, and the vertical axis represents the capacitor voltage V C. Graph G1 shows the change in the capacitor voltage V C over time. As shown in graph G1, the capacitor voltage V C is controlled to converge to the target voltage V C A. The target voltage VCA is set to a value equal to or lower than the withstand voltage VCM of the MOSFET.

[0038] Between time T0 and time T2, capacitor voltage VC is higher than target voltage VCA, so voltage control unit 315 uses voltage control circuit 33 to control q-axis current JQ in a direction that increases running power. As a result, between time T0 and time T1, the increase rate per unit time of capacitor voltage VC decreases, and between time T1 and time T2, capacitor voltage VC decreases. As such, because the feedback control system (particularly the motor coil) has inertia, it takes the time from time T0 to time T1 for capacitor voltage VC to decrease. Furthermore, in the range from time T2 to time T4, capacitor voltage VC is smaller than target voltage VCA, so voltage control unit 315 uses voltage control circuit 33 to control q-axis current JQ in a direction that increases regenerative power. As a result, the amount of decrease per unit time of capacitor voltage VC decreases from time T2 to time T3, and capacitor voltage VC increases from time T3 to time T4. As such, because the feedback control system (particularly the motor coil) has inertia, it takes the time from time T2 to time T3 for capacitor voltage VC to increase.

[0039] Furthermore, in the range from time T4 to time T6, the capacitor voltage VC is higher than the target voltage VCA, so the voltage control unit 315 controls the q-axis current JQ in a direction in which the running power increases, using the voltage control circuit 33. As a result, the increase rate per unit time of the capacitor voltage VC decreases from time T4 to time T5, and the capacitor voltage VC decreases from time T5 to time T6. Furthermore, in the range from time T6 to time T8, capacitor voltage VC is smaller than target voltage VCA, so voltage control unit 315 controls q-axis current JQ in a direction that increases regenerative power using voltage control circuit 33. As a result, the amount of decrease per unit time of capacitor voltage VC decreases from time T6 to time T7, and capacitor voltage VC increases from time T7 to time T8. In this way, the voltage control unit 315 controls the motor 15 to repeatedly control the direction in which the running power increases and the direction in which the regenerative power increases, thereby controlling the capacitor voltage VC to converge to the target voltage VCA.

[0040] For example, at time TS, the rotation speed of motor 15 falls below the threshold, so voltage control unit 315 sets d-axis current JD and q-axis current JQ to zero. When current control is then terminated (all MOSFETs are turned off), torque falls to approximately zero, causing the rotation speed to decrease. As the rotation speed decreases, the induced voltage also decreases. As a result, capacitor voltage VC also decreases.

[0041] [5. Processing of control device] Next, the processing of the control device 3 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing an example of the processing of the control device 3. First, in step S101, the voltage control unit 315 determines whether the contactor 12 is off. If the voltage control unit 315 determines that the contactor 12 is not off (step S101; NO), the process goes to a standby state. If the voltage control unit 315 determines that the contactor 12 is off (step S101; YES), the process proceeds to step S103. Then, in step S103, the voltage acquisition unit 311 acquires the capacitor voltage VC from the voltage sensor SV. The capacitor voltage VC is the voltage across the capacitor 13. Next, in step S105, the current acquisition unit 312 acquires the current values ​​IU, IV, and IW from the current sensor SC. The current value IU is the value of the current flowing through the motor coil 15U. The current value IV is the value of the current flowing through the motor coil 15V. The current value IW is the value of the current flowing through the motor coil 15W. Next, in step S107, the angle acquisition unit 313 acquires the rotation angle θ and the rotation angular velocity ω from the angle sensor SA. The rotation angle θ is the rotation angle of the motor 15, and the rotation angular velocity ω is the rotation angular velocity of the motor 15.

[0042] Next, in step S109, the axis current calculation unit 314 calculates the q-axis current value IQ and the d-axis current value ID from the current values ​​IU, IV, IW, and the rotation angle θ. The axis current calculation unit 314 calculates the q-axis current value IQ using the above-mentioned equation (1), and calculates the d-axis current value ID using equation (3), for example. Next, in step S111, the voltage control unit 315 determines whether the capacitor voltage VC is greater than the target voltage VCA. If the voltage control unit 315 determines that the capacitor voltage VC is greater than the target voltage VCA (step S111; YES), the process proceeds to step S117. If the voltage control unit 315 determines that the capacitor voltage VC is not greater than the target voltage VCA (step S111; NO), the process proceeds to step S113. Then, in step S113, the voltage control unit 315 determines whether the capacitor voltage VC is smaller than the target voltage VCA. If the voltage control unit 315 determines that the capacitor voltage VC is not smaller than the target voltage VCA (step S113; NO), the process proceeds to step S119. If the voltage control unit 315 determines that the capacitor voltage VC is smaller than the target voltage VCA (step S113; YES), the process proceeds to step S115. Then, in step S115, voltage control unit 315 controls q-axis current JQ in a direction that increases the regenerative power, after which the process proceeds to step S119.

[0043] If the answer is YES in step S111, in step S117, the voltage control unit 315 controls the q-axis current JQ in a direction in which the running power increases, after which the process proceeds to step S119. Then, in step S119, the voltage control unit 315 determines whether the rotation speed of the motor 15 is equal to or less than a threshold value. If the voltage control unit 315 determines that the rotation speed of the motor 15 is not equal to or less than the threshold value (step S119; NO), the process returns to step S101. If the voltage control unit 315 determines that the rotation speed of the motor 15 is equal to or less than the threshold value (step S119; YES), the process proceeds to step S121. Then, in step S121, the voltage control section 315 causes the motor driver circuit 2 to control the motor driver 14 so that the d-axis current JD and the q-axis current JQ become zero. After that, the process ends.

[0044] Step S103 corresponds to an example of a "voltage acquisition step". Step S105 corresponds to an example of a "current acquisition step". Step S107 corresponds to an example of an "angle acquisition step". Step S109 corresponds to an example of an "axial current calculation step". Steps S111 to S117 correspond to an example of a "voltage control step".

[0045] [6. Composition and Effects] As described above, the vehicle drive control device 100 according to this embodiment includes a motor driver 14 configured with MOSFETs and controlling the motor 15 that drives the vehicle; a contactor 12 arranged between the battery 11 and the motor driver 14; a capacitor 13 arranged between the positive terminal 14P and the negative terminal 14M of the motor driver 14; and a control device 3 that controls the motor driver 14. The control device 3 includes a voltage acquisition unit 311 that acquires a capacitor voltage VC; a current acquisition unit 312 that acquires current values ​​IU, IV, and IW flowing through each coil of the motor 15; an angle acquisition unit 313 that acquires a rotation angle θ of the motor 15; an axis current calculation unit 314 that calculates a q-axis current value IQ and a d-axis current value ID from the current values ​​IU, IV, IW, and the rotation angle θ; and a voltage control unit 315 that controls the q-axis current JQ when the contactor 12 is off to maintain the capacitor voltage VC at or below a predetermined voltage. According to this configuration, when the contactor 12 is off, the capacitor voltage VC can be maintained at or below a predetermined voltage by controlling the q-axis current JQ. Therefore, by setting the predetermined voltage to an appropriate value, it is possible to suppress overcurrent in the MOSFET constituting the motor driver 14.

[0046] Furthermore, in the vehicle drive control device 100, when the capacitor voltage VC is greater than the target voltage VCA, the voltage control unit 315 controls the q-axis current JQ in a direction that increases the running power, and when the capacitor voltage VC is smaller than the target voltage VCA, the voltage control unit 315 controls the q-axis current JQ in a direction that increases the regenerative power. According to this configuration, when the capacitor voltage VC is greater than the target voltage VCA, the q-axis current JQ is controlled in a direction that increases the running power. Therefore, power is consumed by the motor 15, and the capacitor voltage VC decreases. On the other hand, when the capacitor voltage VC is smaller than the target voltage VCA, the q-axis current JQ is controlled in a direction that increases the regenerative power. Therefore, the power generated by the motor 15 is regenerated in the capacitor 13, and the capacitor voltage VC increases. Therefore, the capacitor voltage VC can be controlled to converge to the target voltage VCA.

[0047] Furthermore, in the vehicle drive control device 100, the target voltage VCA is set to a voltage value that is less than the withstand voltage VCM of the MOSFE and is equal to or greater than a voltage value that allows field-weakening control of the motor 15. According to this configuration, by controlling the q-axis current JQ, the capacitor voltage VC can be maintained at a predetermined voltage or less, and field-weakening control becomes possible in the high rotation speed range, making it possible to drive and control the motor 15.

[0048] Furthermore, in the vehicle drive control device 100, the voltage control unit 315 sets the d-axis current JD and the q-axis current JQ to zero when the rotation speed of the motor 15 becomes equal to or less than a threshold value. According to this configuration, when the rotation speed of the motor 15 falls below a threshold value, the d-axis current JD and the q-axis current JQ are set to zero, so the torque generated by the motor 15 can be set to zero, allowing the user to easily stop the vehicle.

[0049] The control method for a vehicle drive control device 100 according to this embodiment includes a motor driver 14 configured with MOSFETs and controlling a motor 15 that drives the vehicle, a contactor 12 arranged between a battery 11 and the motor driver 14, a capacitor 13 arranged between a positive terminal 14P and a negative terminal 14M of the motor driver 14, and a control device 3 that controls the motor driver 14. The control device 3 executes the following steps: a voltage acquisition step of acquiring a capacitor voltage VC; a current acquisition step of acquiring current values ​​IU, IV, and IW flowing through each coil of the motor 15; an angle acquisition step of acquiring a rotation angle θ of the motor 15; an axis current calculation step of calculating a q-axis current value IQ and a d-axis current value ID from the current values ​​IU, IV, IW, and the rotation angle θ; and a voltage control step S of controlling the q-axis current JQ when the contactor 12 is off to maintain the capacitor voltage VC at or below a predetermined voltage. According to this configuration, when the contactor 12 is off, the capacitor voltage VC can be maintained at or below a predetermined voltage by controlling the q-axis current JQ. Therefore, by setting the predetermined voltage to an appropriate value, it is possible to suppress overcurrent in the MOSFET constituting the motor driver 14.

[0050] 7. Other Embodiments The present invention is not limited to the configurations of the above-described embodiments, and can be implemented in various forms without departing from the spirit of the invention.

[0051] For example, in the above embodiment, the "switching element" is a MOSFET, but is not limited to this. The "switching element" may be, for example, a power transistor or an IGBT (Insulated Gate Bipolar Transistor).

[0052] In the above embodiment, the "voltage control unit" is described as being configured from the voltage control unit 315 and the voltage control circuit 33, but this is not limiting. The voltage control circuit 33 may be configured as a part of the voltage control unit 315. In other words, the function of the voltage control circuit 33 may be realized as a functional unit by the processor 31.

[0053] At least some of the functional blocks shown in Figure 2 may be realized by hardware, or may be realized by a combination of hardware and software, and are not limited to a configuration in which independent hardware resources are arranged as shown in the figure. The control program 321 executed by the processor 31 of the control device 3 of the vehicle drive control device 100 is stored in the memory 32, but the control program 321 may also be stored in an external HDD or the like.

[0054] The processing units in the flowchart shown in FIG. 5 are divided according to the main processing content to facilitate understanding of the processing of the control device 3 of the vehicle drive control device 100. The embodiment is not limited by the way in which the processing units are divided or the names of the processing units shown in the flowchart in FIG. 5. The processing of the control device 3 can be divided into more processing units depending on the processing content, or one processing unit can be divided so that it includes more processes. The processing order of the above flowchart is not limited to the example shown in the figure.

[0055] The control method of the control device 3 can be realized by having the processor 31 of the control device 3 execute a control program 321 corresponding to the control method of the control device 3. The control program 321 can be recorded on a computer-readable recording medium. The recording medium can be a magnetic or optical recording medium or a semiconductor memory device. Specifically, examples include portable or fixed recording media such as flexible disks, CD-ROMs (Compact Disk Read Only Memory), DVDs (Digital Versatile Discs), Blu-ray (registered trademark) Discs, magneto-optical disks, flash memories, and card-type recording media. The recording medium may be a non-volatile storage device such as a RAM, a ROM, or a HDD, which is an internal storage device provided in the control device 3. A control program 321 corresponding to the control method of the control device 3 is stored in a server device or the like, and the control method of the control device 3 can be realized by downloading the control program 321 from the server device to the control device 3.

[0056] 8. Configurations Supported by the Above Embodiments The above embodiment supports the following configurations.

[0057] (Configuration 1) A vehicle drive control device comprising: a motor driver composed of switching elements and controlling a motor that drives a vehicle; a switch arranged between a power source and the motor driver; a capacitor arranged between a positive terminal and a negative terminal of the motor driver; and a control device that controls the motor driver, wherein the control device comprises: a voltage acquisition unit that acquires the capacitor voltage; a current acquisition unit that acquires the value of a current flowing through each coil of the motor; an angle acquisition unit that acquires the rotation angle and rotation angular velocity of the motor; an axis current calculation unit that calculates a q-axis current value and a d-axis current value from the current value, the rotation angle, and the rotation angular velocity; and a voltage control unit that controls the q-axis current to maintain the capacitor voltage at or below a predetermined voltage when the switch is off. According to the vehicle drive control device of configuration 1, when the switch is off, the q-axis current is controlled to keep the capacitor voltage below a predetermined voltage. Therefore, by setting the predetermined voltage to an appropriate value, it is possible to suppress overcurrent in the switching elements that make up the motor driver.

[0058] (Configuration 2) The vehicle drive control device according to configuration 1, wherein the voltage control unit controls the q-axis current in a direction that increases running power when the capacitor voltage is greater than a target voltage, and controls the q-axis current in a direction that increases regenerative power when the capacitor voltage is less than the target voltage. According to the vehicle drive control device of configuration 2, the capacitor voltage can be controlled so as to converge to the target voltage.

[0059] (Configuration 3) The vehicle drive control device according to configuration 2, wherein the target voltage is set to a voltage value that is less than the withstand voltage of the switching element and is equal to or greater than a voltage value that allows field-weakening control of the motor. According to the vehicle drive control device of configuration 3, by controlling the q-axis current, the capacitor voltage can be maintained at a predetermined voltage or less, and field-weakening control becomes possible in the high rotation speed range, making it possible to drive and control the motor.

[0060] (Configuration 4) The vehicle drive control device according to any one of configurations 1 to 3, wherein the voltage control unit reduces the d-axis current and the q-axis current to zero when the rotation speed of the motor becomes equal to or less than the threshold value. According to the vehicle drive control device of configuration 4, the user can easily stop the vehicle.

[0061] (Configuration 5) A control method for a vehicle drive control device comprising: a motor driver composed of a switching element and controlling a motor that drives a vehicle; a switch arranged between a power source and the motor driver; a capacitor arranged between the positive terminal and the negative terminal of the motor driver; and a control device that controls the motor driver, wherein the control device executes a voltage acquisition step that acquires the capacitor voltage; a current acquisition step that acquires the current value flowing through each coil of the motor; an angle acquisition step that acquires the rotation angle of the motor; an axis current calculation step that calculates a q-axis current value and a d-axis current value from the current value and the rotation angle; and a voltage control step that, when the switch is off, controls the q-axis current to maintain the capacitor voltage at or below a predetermined voltage. According to the control method for a vehicle drive control device of configuration 5, when the switch is off, the q-axis current is controlled to keep the capacitor voltage below a predetermined voltage. Therefore, by setting the predetermined voltage to an appropriate value, it is possible to suppress overcurrent in the switching elements that make up the motor driver. [Explanation of symbols]

[0062] 100 Vehicle drive control device 1 Motor drive circuit 11 Battery 12 Contactor (switch) 13 Capacitor 14 Motor driver 14P positive terminal 14M negative terminal 14U1, 14U2, 14V1, 14V2, 14W1, 14W2 MOSFET (switching element) 15 motors, 15U, 15V, 15W motor coil 2 Driver drive circuit 3. Control device 31 processors 311 Voltage acquisition unit 312 Current acquisition section 313 Angle acquisition part 314 Axial current calculation section 315 Voltage control section 32 Memory 321 Control Program 33 Voltage control circuit (part of voltage control section) 331 Differentiator 332 PID Controller IQ q-axis current value IQA target value JD d-axis current JQ q-axis current SA angle sensor SC Current Sensor SV voltage sensor VC Capacitor Voltage VCA target voltage VCM withstand voltage ΔVC difference θ rotation angle

Claims

1. a motor driver configured with switching elements and controlling a motor that drives a vehicle; a switch disposed between a power source and the motor driver; a capacitor disposed between a positive terminal and a negative terminal of the motor driver; a control device that controls the motor driver, The control device a voltage acquisition unit that acquires a capacitor voltage; a current acquisition unit that acquires a current value flowing through each coil of the motor; an angle acquisition unit that acquires a rotation angle of the motor; an axis current calculation unit that calculates a q-axis current value and a d-axis current value from the current value and the rotation angle; a voltage control unit that controls a q-axis current when the switch is off to maintain the capacitor voltage at or below a predetermined voltage; Equipped with The predetermined voltage is set to a value smaller than a withstand voltage of the switching element.

2. the voltage control unit controls the q-axis current in a direction to increase running power when the capacitor voltage is greater than a target voltage, and controls the q-axis current in a direction to increase regenerative power when the capacitor voltage is smaller than the target voltage. The vehicle drive control device according to claim 1.

3. the target voltage is set to a voltage value that is less than the withstand voltage of the switching element and that is equal to or greater than a voltage value that allows field-weakening control of the motor. The vehicle drive control device according to claim 2.

4. the voltage control unit sets the d-axis current and the q-axis current to zero when the rotation speed of the motor becomes equal to or less than a threshold value. The vehicle drive control device according to any one of claims 1 to 3.

5. a motor driver configured with switching elements and controlling a motor that drives a vehicle; a switch disposed between a power source and the motor driver; a capacitor disposed between a positive terminal and a negative terminal of the motor driver; a control device that controls the motor driver, The control device a voltage acquisition step of acquiring a capacitor voltage; a current acquisition step of acquiring a current value flowing through each coil of the motor; an angle acquisition step of acquiring a rotation angle of the motor; an axis current calculation step of calculating a q-axis current value and a d-axis current value from the current value and the rotation angle; a voltage control step of controlling a q-axis current when the switch is off to maintain the capacitor voltage at or below a predetermined voltage; Run The control method for a vehicle drive control device, wherein the predetermined voltage is set to a value smaller than a withstand voltage of the switching element.

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