Vehicle drive control device and control method of vehicle drive control device

Abstract

A vehicle drive control device and a control method thereof are provided, which suppress overcurrent of a switching element constituting a motor driver. The vehicle drive control device (100) is provided with a motor driver (14), a contactor (12), a capacitor (13), and a control device (3). The control device (3) is provided with: a voltage acquisition unit (311) that acquires a capacitor voltage (VC); a current acquisition unit (312) that acquires current values (IU, IV, IW) of currents 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) based on the current values (IU, IV, IW) and the rotation angle (θ); and a voltage control unit (315) that controls the q-axis current (JQ) to keep the capacitor voltage (VC) below a prescribed voltage when the contactor (12) is turned off.

Description

Technical Field

[0001] This invention relates to a vehicle drive control device and a control method for the vehicle drive control device. Background Technology

[0002] Previously, there were known technologies related to vehicle drive control devices that were mounted on vehicles and driven by motors.

[0003] For example, Patent Document 1 describes a motor driver that short-circuits the AC output terminal of the motor driver (inverter) in the event of an abnormality. Furthermore, it discloses that if the contactor is disconnected during motor operation and the motor induced voltage rises, the control circuit and other components are activated to perform control that does not exceed the withstand voltage.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2014-183702 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, if a vehicle malfunction causes a short circuit at the AC output terminal of the motor driver, a large motor current will be generated depending on the type of motor. Therefore, in order to prevent damage to the switching elements that make up the motor driver, it is necessary to suppress the overcurrent.

[0009] Methods for solving problems

[0010] One aspect of the present invention is a vehicle drive control device comprising: a motor driver consisting of a switching element for controlling a motor driving 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; and a control device for controlling the motor driver, the control device comprising: a voltage acquisition unit for acquiring the voltage of the capacitor; a current acquisition unit for acquiring the current value of the current flowing in each coil of the motor; an angle acquisition unit for acquiring the rotation angle of the motor; an axis current calculation unit for calculating a q-axis current value and a d-axis current value based on the current value and the rotation angle; and a voltage control unit for maintaining the capacitor voltage below a predetermined voltage by controlling the q-axis current when the switch is open.

[0011] The effects of the invention

[0012] According to the present invention, overcurrent in the switching elements constituting the motor driver can be suppressed. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating an example of the structure of a vehicle drive control device.

[0014] Figure 2 This is a diagram illustrating an example of the structure of a control device.

[0015] Figure 3 This is a diagram illustrating an example of the structure of a voltage control circuit.

[0016] Figure 4 This is a graph showing an example of capacitor voltage.

[0017] Figure 5 This is a flowchart illustrating an example of the processing of the control device.

[0018] Label Explanation

[0019] 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: MOSFETs (switching elements); 15: Motor; 15U, 15V, 15W: Motor coil; 2: Driver drive circuit; 3: Control device; 31: Processor; 311: Voltage acquisition unit; 312: Current acquisition unit; 31 3: Angle acquisition unit; 314: Axis current calculation unit; 315: Voltage control unit; 32: Memory; 321: Control program; 33: Voltage control circuit (part of the voltage control unit); 331: Differential converter; 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: Differential; θ: Rotation angle. Detailed Implementation

[0020] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0021] [1. Structure of Vehicle Drive Control Device]

[0022] First, refer to Figure 1 The structure of the vehicle drive control device 100 will be described. Figure 1 This is a diagram showing an example of the structure of a vehicle drive control device 100.

[0023] like Figure 1 As shown, the vehicle drive control device 100 includes a motor drive circuit 1, a driver drive circuit 2, and a control device 3.

[0024] Motor drive circuit 1 is a circuit that drives motor 15 and includes battery 11, contactor 12, capacitor 13 and motor driver 14.

[0025] Battery 11 supplies power to motor 15 via motor driver 14.

[0026] Battery 11 corresponds to an example of "power supply".

[0027] Contactor 12 is positioned between battery 11 and motor driver 14. Contactor 12 disconnects in the event of a vehicle malfunction. When contactor 12 disconnects, the power supply from battery 11 to motor driver 14 is cut off.

[0028] Contactor 12 corresponds to an example of a "switch".

[0029] Capacitor 13 is disposed between the positive terminal 14P and the negative terminal 14M of motor driver 14. Capacitor 13 applies a capacitor voltage VC between the positive terminal 14P and the negative terminal 14M of motor driver 14, and the capacitor voltage VC is detected by voltage sensor SV.

[0030] When contactor 12 is disconnected, power is supplied from capacitor 13 to motor 15 via motor driver 14 to power motor 15, i.e., to drive motor 15. In this case, capacitor voltage VC decreases.

[0031] Additionally, when contactor 12 is disconnected, during the regenerative operation of motor 15, power is regenerated from motor 15 to capacitor 13 via motor driver 14. In this case, capacitor voltage VC increases.

[0032] The motor driver 14 consists of MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors) 14U1, MOSFET 14U2, MOSFET 14V1, MOSFET 14V2, MOSFET 14W1, and MOSFET 14W2. These six MOSFETs are turned on and off according to the instructions from the driver drive circuit 2.

[0033] MOSFET is an example of a "switching element".

[0034] Motor 15 is, for example, a three-phase synchronous motor using permanent magnets. Additionally, such as... Figure 1 As shown, the motor 15 includes a motor coil 15U, a motor coil 15V, and a motor coil 15W.

[0035] The motor 15 drives the vehicle by electricity supplied from the battery 11 via the motor driver 14. The vehicle is, for example, a motorcycle (automobile two-wheeler).

[0036] In this embodiment, the case where the vehicle is a motorcycle (autonomous two-wheeled vehicle) is described, but it is not limited to this. The vehicle may be, for example, a four-wheeled passenger car or a four-wheeled large vehicle. In addition, the vehicle may also be, for example, a tractor or other work vehicle.

[0037] A voltage sensor SV is configured for capacitor 13. The voltage sensor SV detects the voltage between the two ends of capacitor 13, i.e., capacitor voltage VC. The voltage sensor SV outputs the detected capacitor voltage VC to the control device 3.

[0038] A current sensor SC is disposed between the motor driver 14 and the motor 15. The current sensor SC detects the current values ​​flowing through each coil of the motor 15. Specifically, the current sensor SC detects the current value IU flowing through motor coil 15U, the current value IV flowing through motor coil 15V, and the current value IW flowing through motor coil 15W. The current sensor SC outputs the detected current values ​​IU, IV, and IW to the control device 3. The configuration of the current sensor SC is not limited to this. The current sensor SC can also be disposed on the lower MOSFET.

[0039] An angle sensor SA is provided for the motor 15. The angle sensor SA consists of a rotary transformer, a Hall element, etc., and detects the rotation angle θ and rotational angular velocity ω of the motor 15. The angle sensor SA outputs the detected rotation angle θ and rotational angular velocity ω to the control device 3.

[0040] The driver drive circuit 2 controls the motor driver 14 according to the instructions from the control device 3. That is, the driver drive circuit 2 controls the turn-on and turn-off of the six MOSFETs constituting the motor driver 14 according to the instructions from the control device 3.

[0041] The control device 3 controls the driver drive circuit 2 based on the capacitor voltage VC, current values ​​IU, IV, and IW, rotation angle θ, and rotational angular velocity ω. When contactor 12 is open, the control device 3 performs field weakening control on the motor 15, for example. This field weakening control can also begin when contactor 12 is in the closed state and continue even when contactor 12 changes to the open state. Additionally, the control device 3 controls the motor 15, for example, to maintain the capacitor voltage VC below a specified voltage. The specified voltage is set to a value smaller than the withstand voltage VCM of the MOSFET constituting the motor driver 14.

[0042] Reference Figures 2-5The control device 3 will be further explained.

[0043] [2. Structure of the control device]

[0044] Next, refer to Figure 2 The structure of control device 3 will be described. Figure 2 This is a diagram showing an example of the structure of control device 3.

[0045] The control device 3 controls the motor 15 via the driver drive 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.

[0046] The control device 3 is, for example, composed of an ECU (Electronic Control Unit). The control device 3 includes a processor 31, a memory 32, and a voltage control circuit 33.

[0047] When contactor 12 is open, voltage control circuit 33 controls the q-axis current value IQ, so that capacitor voltage VC becomes target voltage VCA.

[0048] The voltage control circuit 33 constitutes part of the "voltage control unit".

[0049] Reference Figure 3 The voltage control circuit 33 will be further explained.

[0050] Memory 32 is a storage device that non-volatilely stores programs and data executed by processor 31. Memory 32 is composed of semiconductor storage elements such as magnetic storage devices, flash memory (ROM), or other types of non-volatile storage devices. Furthermore, memory 32 may also include RAM (Random Access Memory) that constitutes the working area of ​​processor 31. Memory 32 stores data processed by control device 3 and control program 321 executed by processor 31.

[0051] The processor 31 can be a single processor or multiple processors that function as processor 31. The processor 31 executes the control program 321, thereby controlling the motor 15 via the driver drive circuit 2 and the motor driver 14.

[0052] The control device 3 includes a voltage acquisition unit 311, a current acquisition unit 312, an angle acquisition unit 313, an shaft current calculation unit 314, and a voltage control unit 315. Specifically, the processor 31 of the control device 3 functions as the voltage acquisition unit 311, the current acquisition unit 312, the angle acquisition unit 313, the shaft current calculation unit 314, and the voltage control unit 315 by executing a control program 321.

[0053] The voltage acquisition unit 311 acquires the capacitor voltage VC from the voltage sensor SV. The capacitor voltage VC is the voltage between the two terminals of capacitor 13.

[0054] The current acquisition unit 312 acquires current values ​​IU, IV, and IW from the current sensor SC. Current value IU is the value of the current flowing through the motor coil 15U. Current value IV is the value of the current flowing through the motor coil 15V. Current value IW is the value of the current flowing through the motor coil 15W.

[0055] The angle acquisition unit 313 acquires the rotation angle θ and rotational angular velocity ω from the angle sensor SA. The rotation angle θ is the rotation angle of the motor 15, and the rotational angular velocity ω is the rotational angular velocity of the motor 15.

[0056] In this embodiment, the case where the angle acquisition unit 313 acquires the rotation angle θ and rotational angular velocity ω from the angle sensor SA will be described, but it is not limited to this. For example, the angle acquisition unit 313 may also acquire the rotation angle θ from the angle sensor SA and calculate the rotational angular velocity ω based on the rotation angle θ.

[0057] The axis current calculation unit 314 calculates the q-axis current value IQ and the d-axis current value ID based on the current value IU, the current value IV, the current value IW, and the rotation angle θ.

[0058] The q-axis current calculation unit 314 calculates the q-axis current value IQ, for example, using the following formula (1).

[0059] IQ=[cos(θD)×IU+cos(θD-2π / 3)×IV+cos(θD+2π / 3)×IW]×(2 / 3) 1 / 2 (1)

[0060] Furthermore, the rotation angle θD is obtained by the following equation (2).

[0061] θD=θ×NP / 2 (2)

[0062] Here, the number of poles NP is the number of poles of the rotor.

[0063] In addition, the shaft current calculation unit 314 calculates the d-axis current value ID, for example, by the following formula (3).

[0064] ID=[-sin(θD)×IU-sin(θD-2π / 3)×IV-sin(θD+2π / 3)×IW]×(2 / 3) 1 / 2 (3)

[0065] When contactor 12 is open, voltage control unit 315 maintains capacitor voltage VC below a specified voltage by controlling q-axis current JQ. In this embodiment, voltage control unit 315 maintains capacitor voltage VC below a specified voltage by controlling q-axis current JQ using voltage control circuit 33.

[0066] For example, when the capacitor voltage VC is greater than the target voltage VCA, the voltage control unit 315 uses the voltage control circuit 33 to control the q-axis current JQ in the direction of increasing the power supply. Conversely, when the capacitor voltage VC is less than the target voltage VCA, the voltage control unit 315 uses the voltage control circuit 33 to control the q-axis current JQ in the direction of increasing the regenerative power.

[0067] By controlling the q-axis current JQ in the direction of increasing power supply, the power is consumed by the motor 15, thus reducing the capacitor voltage VC. By controlling the q-axis current JQ in the direction of increasing regenerated power, the power generated by the motor 15 is regenerated to the capacitor 13, increasing the capacitor voltage VC. In this way, the capacitor voltage VC can be maintained below a specified voltage.

[0068] The target voltage VCA is set to be less than the withstand voltage VCM of the MOSFET constituting the motor driver 14 and above the voltage value that enables field weakening control of the motor 15.

[0069] Since the target voltage VCA is set above a value sufficient for field weakening control of motor 15, field weakening control of motor 15 can be performed. Therefore, it is possible to prevent the capacitor voltage VC from becoming too large and to suppress overcurrent in the MOSFET.

[0070] Furthermore, when the rotational speed of the motor 15 falls below a threshold, the voltage control unit 315 sets the d-axis current JD and the q-axis current JQ to zero. For example, when the rotational speed of the motor 15 falls below a threshold, the voltage control unit 315 causes the driver drive circuit 2 to control the motor driver 14 to make the d-axis current JD and the q-axis current JQ zero. Moreover, the rotational speed of the motor 15 is calculated, for example, based on the rotational angular velocity ω.

[0071] Since the d-axis current JD and q-axis current JQ are zero when the speed of motor 15 is below a threshold, the torque generated by motor 15 can be made approximately zero (e.g., below a specified value). Therefore, the user can easily stop the vehicle.

[0072] [3. Structure of the voltage control circuit]

[0073] Next, refer to Figure 3 The structure of voltage control circuit 33 will be explained. Figure 3 This is a diagram illustrating an example of the structure of a voltage control circuit.

[0074] like Figure 3 As shown, the voltage control circuit 33 forms part of the feedback control system. The voltage control circuit 33 includes a differential circuit 331 and a PID controller 332.

[0075] Differential converter 331 calculates the 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.

[0076] The differential ΔVC is input to the PID controller 332, which outputs the target value IQA of the q-axis current JQ to the driver circuit 2. The PID controller 332 includes a P controller, an I controller, and a D controller. The P gain GP is set in the P controller, the I gain GI is set in the I controller, and the D gain GD is set in the D controller. The P controller outputs the value obtained by multiplying the P gain GP by the differential ΔVC. The I controller outputs the value obtained by multiplying the I gain GI by the time integral of the differential ΔVC. The D controller outputs the value obtained by multiplying the D gain GD by the time derivative of the differential 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.

[0077] The driver circuit 2 controls the motor driver 14, causing the q-axis current JQ to reach the target value IQA. Under the control of the motor driver 14, the motor 15 operates. Corresponding to the operation of the motor 15, the amount of charge stored in the capacitor 13 changes, and the capacitor voltage VC changes. The voltage sensor SV detects the capacitor voltage VC and inputs it to the differential circuit 331.

[0078] Thus, by setting appropriate values ​​in the PID controller 332 as P gain GP, ​​I gain GI, and D gain GD, Figure 3 The feedback control system shown operates to make the capacitor voltage VC converge to the target voltage VCA.

[0079] In this embodiment, the PID controller 332 is described as performing PID control, but it is not limited to this. The PID controller 332 may at least perform I control. For example, the PID controller 332 may perform PI control or ID control.

[0080] [4. Capacitor Voltage]

[0081] Next, refer to Figure 4 An example of the change in capacitor voltage VC controlled by voltage control unit 315 will be explained. Figure 4 This is a graph showing an example of capacitor voltage VC.

[0082] Figure 4 The graph shown has time T on the horizontal axis and capacitor voltage VC on the vertical axis. Curve G1 represents the time-dependent change of capacitor voltage VC. As shown by curve G1, capacitor voltage VC is controlled to converge to the target voltage VCA.

[0083] The target voltage VCA is set below the MOSFET's withstand voltage VCM.

[0084] During the time interval from T0 to T2, the capacitor voltage VC is greater than the target voltage VCA. Therefore, the voltage control unit 315 uses the voltage control circuit 33 to control the q-axis current JQ in the direction of increasing the power supply. As a result, the increase in capacitor voltage VC per unit time decreases during the period from T0 to T1, and decreases during the period from T1 to T2. Thus, due to the inertia of the feedback control system (especially the motor coil), the time from T0 to T1 is required until the capacitor voltage VC decreases.

[0085] Furthermore, during the period from time T2 to time T4, the capacitor voltage VC is lower than the target voltage VCA. Therefore, the voltage control unit 315 uses the voltage control circuit 33 to control the q-axis current JQ in the direction of increasing regenerative power. As a result, during the period from time T2 to time T3, the decrease in capacitor voltage VC per unit time decreases, and during the period from time T3 to time T4, capacitor voltage VC increases. Thus, due to the inertia of the feedback control system (especially the motor coil), the time from time T2 to time T3 is required until the capacitor voltage VC increases.

[0086] Furthermore, during the period from time T4 to time T6, the capacitor voltage VC is greater than the target voltage VCA. Therefore, the voltage control unit 315 uses the voltage control circuit 33 to control the q-axis current JQ in the direction of increasing the power supply. As a result, during the period from time T4 to time T5, the increase in capacitor voltage VC per unit time decreases, and during the period from time T5 to time T6, capacitor voltage VC decreases.

[0087] Furthermore, during the period from time T6 to time T8, the capacitor voltage VC is lower than the target voltage VCA. Therefore, the voltage control unit 315 uses the voltage control circuit 33 to control the q-axis current JQ in the direction of increasing regenerative power. As a result, during the period from time T6 to time T7, the decrease in capacitor voltage VC per unit time decreases, and during the period from time T7 to time T8, capacitor voltage VC increases.

[0088] In this way, the voltage control unit 315 controls the direction of power increase and regenerative power increase of the motor 15 repeatedly, so that the capacitor voltage VC converges to the target voltage VCA.

[0089] Furthermore, for example, at time TS, the rotational speed of motor 15 falls below a threshold, so the voltage control unit 315 makes the d-axis current JD and q-axis current JQ zero. Afterwards, if current control ends (turning off all MOSFETs), the torque is approximately zero, thus reducing the rotational speed. As the rotational speed decreases, the induced voltage decreases. Therefore, the capacitor voltage VC also decreases.

[0090] [5. Control device processing]

[0091] Next, refer to Figure 5 The processing of control device 3 will be explained. Figure 5 This is a flowchart illustrating an example of the processing of control device 3.

[0092] First, in step S101, the voltage control unit 315 determines whether the contactor 12 is disconnected.

[0093] If the voltage control unit 315 determines that the contactor 12 is not disconnected (step S101; No), the process changes to standby mode. If the voltage control unit 315 determines that the contactor 12 is disconnected (step S101; Yes), the process proceeds to step S103.

[0094] 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 between the two terminals of the capacitor 13.

[0095] 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.

[0096] Next, in step S107, the angle acquisition unit 313 acquires the rotation angle θ and rotational angular velocity ω from the angle sensor SA. The rotation angle θ is the rotation angle of the motor 15, and the rotational angular velocity ω is the rotational angular velocity of the motor 15.

[0097] Next, in step S109, the axis current calculation unit 314 calculates the q-axis current value IQ and the d-axis current value ID based on the current value IU, the current value IV, the current value IW, and the rotation angle θ. For example, the axis current calculation unit 314 calculates the q-axis current value IQ using the above-described equation (1) and calculates the d-axis current value ID using equation (3).

[0098] Next, in step S111, the voltage control unit 315 determines whether the capacitor voltage VC is greater than the target voltage VCA.

[0099] 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.

[0100] Then, in step S113, the voltage control unit 315 determines whether the capacitor voltage VC is less than the target voltage VCA.

[0101] If the voltage control unit 315 determines that the capacitor voltage VC is not less 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 less than the target voltage VCA (step S113; Yes), the process proceeds to step S115.

[0102] Then, in step S115, the voltage control unit 315 controls the q-axis current JQ to increase the regenerative power. Then, the process proceeds to step S119.

[0103] If "Yes" is selected in step S111, in step S117, the voltage control unit 315 controls the q-axis current JQ to increase the power supply. Then, the process proceeds to step S119.

[0104] Then, in step S119, the voltage control unit 315 determines whether the speed of the motor 15 is below a threshold.

[0105] If the voltage control unit 315 determines that the speed of the motor 15 is not below the threshold (step S119; No), the process returns to step S101. If the voltage control unit 315 determines that the speed of the motor 15 is below the threshold (step S119; Yes), the process proceeds to step S121.

[0106] Then, in step S121, 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. After that, the process ends.

[0107] Step S103 corresponds to an example of the "voltage acquisition step". Step S105 corresponds to an example of the "current acquisition step". Step S107 corresponds to an example of the "angle acquisition step". Step S109 corresponds to an example of the "axis current calculation step". Steps S111 to S117 correspond to an example of the "voltage control step".

[0108] [6. Structure and Effects]

[0109] As described above, the vehicle drive control device 100 of this embodiment includes: a motor driver 14, which is composed of MOSFETs, and controls a motor 15 that drives a vehicle; a contactor 12, which is disposed between a battery 11 and a motor driver 14; a capacitor 13, which is disposed between a positive terminal 14P and a negative terminal 14M of the motor driver 14; and a control device 3, which controls the motor driver 14. The control device 3 includes: a voltage acquisition unit 311, which acquires the capacitor voltage VC; a current acquisition unit 312, which acquires the current values ​​IU, IV, and IW of the current flowing in each coil of the motor 15; an angle acquisition unit 313, which acquires the rotation angle θ of the motor 15; an axis current calculation unit 314, which calculates the q-axis current value IQ and the d-axis current value ID based on the current values ​​IU, IV, IW, and the rotation angle θ; and a voltage control unit 315, which maintains the capacitor voltage VC below a predetermined voltage by controlling the q-axis current JQ when the contactor 12 is open.

[0110] According to this structure, when contactor 12 is open, the capacitor voltage VC can be maintained below a specified voltage by controlling the q-axis current JQ. Therefore, by setting the specified voltage to an appropriate value, overcurrent in the MOSFET constituting the motor driver 14 can be suppressed.

[0111] In addition, in the vehicle drive control device 100, the voltage control unit 315 controls the q-axis current JQ to increase the power of the power operation when the capacitor voltage VC is greater than the target voltage VCA, and controls the q-axis current JQ to increase the power of the regenerative operation when the capacitor voltage VC is less than the target voltage VCA.

[0112] According to this structure, when the capacitor voltage VC is greater than the target voltage VCA, the q-axis current JQ is controlled in the direction of increasing the power supply. Therefore, power is consumed by the motor 15, and the capacitor voltage VC decreases. Conversely, when the capacitor voltage VC is less than the target voltage VCA, the q-axis current JQ is controlled in the direction of increasing the regenerated power. Therefore, power generated by the motor 15 is regenerated to the capacitor 13, and the capacitor voltage VC increases. Thus, it is possible to control the capacitor voltage VC to converge to the target voltage VCA.

[0113] In addition, in the vehicle drive control device 100, the target voltage VCA is set to be less than the withstand voltage VCM of MOSFE and above the voltage value that enables field weakening control of the motor 15.

[0114] According to this structure, by controlling the q-axis current JQ, the capacitor voltage VC can be kept below a specified voltage, and field weakening control can be performed in the high rotation region, enabling drive control of the motor 15.

[0115] In addition, in the vehicle drive control device 100, the voltage control unit 315 makes the d-axis current JD and the q-axis current JQ zero when the speed of the motor 15 is below a threshold.

[0116] According to this structure, when the speed of motor 15 falls below a threshold, the d-axis current JD and the q-axis current JQ are made zero, thus enabling the torque generated by motor 15 to be zero. Therefore, the user can easily stop the vehicle.

[0117] The control method of the vehicle drive control device 100 in this embodiment includes: a motor driver 14 composed of MOSFETs, which controls a motor 15 that drives a vehicle; a contactor 12 disposed between a battery 11 and the motor driver 14; a capacitor 13 disposed 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. In the control method of the vehicle drive control device 100, the control device 3 performs the following steps: a voltage acquisition step, acquiring the capacitor voltage VC; a current acquisition step, acquiring the current values ​​IU, IV, and IW of the current flowing in each coil of the motor 15; an angle acquisition step, acquiring the rotation angle θ of the motor 15; an axis current calculation step, calculating the q-axis current value IQ and the d-axis current value ID based on the current values ​​IU, IV, IW, and the rotation angle θ; and a voltage control step, maintaining the capacitor voltage VC below a specified voltage by controlling the q-axis current JQ when the contactor 12 is open.

[0118] According to this structure, when contactor 12 is open, the capacitor voltage VC can be maintained below a specified voltage by controlling the q-axis current JQ. Therefore, by setting the specified voltage to an appropriate value, overcurrent in the MOSFET constituting the motor driver 14 can be suppressed.

[0119] [7. Other Implementation Methods]

[0120] Furthermore, the present invention is not limited to the structure of the above-described embodiments, and can be implemented in various ways without departing from its spirit.

[0121] For example, in the above embodiment, the case where the "switching element" is a MOSFET has been described, but it is not limited to this. The "switching element" may be a power transistor or an IGBT (Insulated Gate Bipolar Transistor).

[0122] Furthermore, in the above embodiment, the "voltage control unit" was described as consisting of a voltage control unit 315 and a voltage control circuit 33, but it is not limited to this. The voltage control circuit 33 may also be configured as part of the voltage control unit 315. That is, the function of the voltage control circuit 33 may also be implemented by the processor 31 as a functional unit.

[0123] Figure 2 At least some of the functional blocks shown can be implemented in hardware, or in a combination of hardware and software, and are not limited to configuring independent hardware resources as shown in the figure.

[0124] 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.

[0125] Figure 5 The processing units in the flowchart shown are divided according to the main processing content for easy understanding of the processing of the control device 3 of the vehicle drive control device 100. The implementation method is not subject to change. Figure 5 The flowchart illustrates the method of dividing processing units and the naming restrictions. The control device 3 can divide its processing into more processing units based on the processing content, or it can divide the processing into units containing more processes. The processing order in the flowchart is not limited to the example shown.

[0126] The control method of the control device 3 can be implemented 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 pre-recorded in a recording medium that can be recorded in a computer-readable manner. The recording medium can be a magnetic recording medium, an optical recording medium, or a semiconductor storage device.

[0127] Specifically, examples include portable or stationary recording media such as floppy disks, CD-ROMs (Compact Disk Read Only Memory), DVDs (Digital Versatile Discs), Blu-ray discs, optical disks, flash memory, and card-type recording media.

[0128] The recording medium can also be a non-volatile storage device such as RAM, ROM, or HDD, which is an internal storage device of the control device 3. The control program 321 corresponding to the control method of the control device 3 can be stored in a server device or the like. By downloading the control program 321 from the server device to the control device 3, the control method of the control device 3 can be implemented.

[0129] [8. Structure supported by the above embodiments]

[0130] The above implementation supports the following structures.

[0131] (Structure 1) A vehicle drive control device comprising: a motor driver consisting of a switching element for controlling a motor driving 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; and a control device for controlling the motor driver, the control device comprising: a voltage acquisition unit for acquiring the voltage of the capacitor; a current acquisition unit for acquiring the current value of the current flowing in each coil of the motor; an angle acquisition unit for acquiring the rotation angle and rotational angular velocity of the motor; an axis current calculation unit for calculating a q-axis current value and a d-axis current value based on the current value, the rotation angle, and the rotational angular velocity; and a voltage control unit for maintaining the capacitor voltage below a predetermined voltage by controlling the q-axis current when the switch is open.

[0132] According to the vehicle drive control device of Structure 1, when the switch is open, the capacitor voltage can be maintained below a specified voltage by controlling the q-axis current. Therefore, by setting the specified voltage to an appropriate value, overcurrent in the switching elements constituting the motor driver can be suppressed.

[0133] (Structure 2) The vehicle drive control device of Structure 1, wherein when the capacitor voltage is greater than the target voltage, the voltage control unit controls the q-axis current to increase the power of the power operation, and when the capacitor voltage is less than the target voltage, the voltage control unit controls the q-axis current to increase the power of the regenerative operation.

[0134] According to the vehicle drive control device of structure 2, it is possible to control the capacitor voltage to converge to the target voltage.

[0135] (Structure 3) The vehicle drive control device of Structure 2, wherein the target voltage is set to be less than the withstand voltage of the switching element and above a voltage value that enables field weakening control of the motor.

[0136] According to the vehicle drive control device of structure 3, by controlling the q-axis current, the capacitor voltage can be kept below a specified voltage, and field weakening control can be performed in the high rotation region, thereby enabling drive control of the motor.

[0137] (Structure 4) A vehicle drive control device of any of Structures 1 to 3, wherein when the speed of the motor is below a threshold, the voltage control unit makes the d-axis current and the q-axis current zero.

[0138] According to the vehicle drive control device of structure 4, the user can easily stop the vehicle.

[0139] (Structure 5) A control method for a vehicle drive control device, the vehicle drive control device comprising: a motor driver consisting of a switching element for controlling a motor driving 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; and a control device for controlling the motor driver. In the control method of the vehicle drive control device, the control device performs the following steps: a voltage acquisition step for acquiring the voltage of the capacitor; a current acquisition step for acquiring the current value of the current flowing in each coil of the motor; an angle acquisition step for acquiring the rotation angle of the motor; an axis current calculation step for calculating the q-axis current value and the d-axis current value based on the current value and the rotation angle; and a voltage control step for maintaining the capacitor voltage below a predetermined voltage by controlling the q-axis current when the switch is open.

[0140] According to the control method of the vehicle drive control device in structure 5, when the switch is open, the capacitor voltage can be maintained below a specified voltage by controlling the q-axis current. Therefore, by setting the specified voltage to an appropriate value, overcurrent in the switching elements constituting the motor driver can be suppressed.

Claims

1. A vehicle drive control device, comprising: A motor driver, which consists of switching elements, controls the motor that drives the vehicle; A contactor, which is configured between the power source and the motor driver, is disconnected when the vehicle malfunctions, and when the contactor is disconnected, the power supply from the power source to the motor driver is cut off. A capacitor is disposed between the positive and negative terminals of the motor driver; as well as Control device, which controls the motor driver, The control device includes: The voltage acquisition unit acquires the capacitor voltage; The current acquisition unit acquires the current value of the current flowing through each coil of the motor; An angle acquisition unit acquires the rotation angle of the motor; The axis current calculation unit calculates the q-axis current value and the d-axis current value based on the current value and the rotation angle; as well as Voltage control unit, Even when the contactor has changed to the open state, the control device continues to perform the field weakening control of the motor that began when the contactor was in the closed state. When the contactor is disconnected, the voltage control unit controls the q-axis current so that the capacitor voltage becomes a target voltage, which is less than the withstand voltage of the switching element and above the voltage value that enables the field weakening control of the motor.

2. The vehicle drive control device according to claim 1, wherein, The voltage control unit generates a target value for the q-axis current based on the difference between the capacitor voltage and the target voltage of the capacitor. By controlling the motor driver so that the q-axis current becomes the target value, the capacitor voltage converges to the target voltage. When the capacitor voltage is greater than the target voltage, the voltage control unit controls the q-axis current to increase the power supply for power operation; when the capacitor voltage is less than the target voltage, the voltage control unit controls the q-axis current to increase the power supply for regeneration.

3. The vehicle drive control device according to claim 1 or 2, wherein, When the motor speed falls below a threshold, the voltage control unit sets the d-axis current and the q-axis current to zero.

4. A control method for a vehicle drive control device, the vehicle drive control device comprising: a motor driver, which is composed of a switching element and controls a motor that drives a vehicle; a contactor disposed between a power source and the motor driver, which is disconnected when the vehicle malfunctions, and in the case of the contactor being disconnected, the power supply from the power source to the motor driver is cut off. A capacitor disposed between the positive and negative terminals of the motor driver; and a control device for controlling the motor driver. In the control method of the vehicle drive control device, the control device performs the following steps: The voltage acquisition step involves obtaining the capacitor voltage. The current acquisition step involves acquiring the current values ​​of the current flowing through each coil of the motor. The angle acquisition step obtains the rotation angle of the motor; The axis current calculation steps involve calculating the q-axis current value and the d-axis current value based on the current value and the rotation angle. as well as Voltage control steps, Furthermore, even when the contactor has changed to the open state, the control device continues the field weakening control of the motor that began when the contactor was in the closed state. In the voltage control step, when the contactor is open, the q-axis current is controlled such that the capacitor voltage becomes a target voltage, which is less than the withstand voltage of the switching element and above the voltage value that enables the field weakening control of the motor.

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