JP2023081727A - vehicle controller - Google Patents

Abstract

An object of the present invention is to ensure control stability while reducing heat generation in switching elements in a state where wheels are mechanically restrained. A rotary electric machine that drives drive wheels via a power transmission mechanism, a power conversion device that converts DC power into AC power using a switching element, and a power conversion device that is controlled to respond to the amount of depression of an accelerator pedal. a control unit for outputting a torque corresponding to the torque command value determined by the above from the rotating electric machine; When a locked state is detected by the lock detection unit, the control unit suppresses non-interference control of the current feedback system compared to a case where the locked state is not detected, while increasing the torque. The command value is changed at a predetermined frequency by the amount of change that is absorbed by the torsion of the power transmission mechanism. [Selection drawing] Fig. 5

Description

The present invention relates to a vehicle control device.

2. Description of the Related Art It is known that in a vehicle equipped with a driving motor, switching elements of the inverter generate heat and the temperature rises when torque is output from the motor while the wheels are mechanically restrained. When the wheels are mechanically constrained, the rotor is also mechanically constrained. Therefore, even if the current for driving the motor is applied to the motor in this state, the rotor cannot rotate, and only one phase out of the multiple phases can be generated. current concentrates in As a result, the heat generated in the switching elements of the concentrated phases increases. Therefore, techniques have been developed to reduce the heat generated by the switching elements when the wheels are mechanically restrained.

For example, Patent Literature 1 discloses that, in order to protect switching elements from heat generation, control is executed to vary the motor torque at the torsional resonance frequency of the drive shaft while the wheels are mechanically restrained. . In this control, the motor torque is alternately oscillated in positive and negative directions to generate torsion in the drive shaft. As a result, the rotor slightly rotates alternately in the positive and negative directions even when the wheels are mechanically restrained. Therefore, since the current can be evenly distributed to the three phases, it is possible to prevent the current from concentrating on one phase.

Japanese Patent No. 4655667

However, when the inventors of the present invention conducted an actual machine verification, it became clear that an overcurrent occurs in the phase current in the control described in Patent Document 1. If an overcurrent occurs in the phase current, there is a problem that control stability and thermal performance deteriorate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a control device for a vehicle that can ensure control stability while reducing heat generation in switching elements in a state where wheels are mechanically restrained. intended to provide

The present invention provides a rotating electrical machine that drives drive wheels via a power transmission mechanism, a power conversion device that converts DC power into AC power using a switching element and supplies the power to the rotating electrical machine, and a power conversion device that controls the power conversion device. a control unit for executing drive control for causing the rotating electric machine to output a torque corresponding to a torque command value determined according to the amount of depression of an accelerator pedal; and a lock detection unit for detecting that the lock state is a locked state, wherein the control unit detects that the lock state is detected by the lock detection unit. The torque command value is changed at a predetermined frequency by the amount of change absorbed by the torsion of the power transmission mechanism while suppressing the non-interference control of the current feedback system compared to the case of no detection.

According to this configuration, it is possible to suppress the occurrence of overcurrent by suppressing the non-interfering control of the current feedback system when executing the control that oscillates the torque and causes the torsion of the power transmission mechanism. Thereby, heat generation of the switching element can be suppressed.

Further, the predetermined frequency may be a torsional resonance frequency of the power transmission mechanism.

According to this configuration, a large torsional displacement amount can be obtained with a small torque fluctuation by setting the torque vibration to the torsional resonance frequency of the power transmission mechanism.

Further, the control unit may disable the non-interference control when suppressing the non-interference control.

According to this configuration, generation of overcurrent can be eliminated by invalidating the non-interference control.

In addition, the control unit may perform the non-interference control by reducing the non-interference control by a predetermined ratio compared to when the lock state is not detected when suppressing the non-interference control.

According to this configuration, it is possible to secure the controllability of the motor torque while suppressing the overcurrent by reducing the non-interference control at a constant rate.

Further, the control unit may restrict an upper limit value and a lower limit value of the non-interference control when suppressing the non-interference control.

According to this configuration, by setting the upper limit value and the lower limit value of the non-interference control so that overcurrent does not occur, the controllability when the state in which the wheels are mechanically restrained ends and the normal motor control is performed. can be stabilized.

In the present invention, it is possible to suppress the occurrence of overcurrent by suppressing the non-interfering control of the current feedback system when executing the control that oscillates the torque and causes the torsion of the power transmission mechanism. Thereby, heat generation of the switching element can be suppressed.

FIG. 1 is a diagram schematically showing the configuration of a vehicle according to an embodiment. FIG. 2 is a block diagram showing the configuration of the control device. FIG. 3 is a block diagram showing the configuration of the controller in more detail. FIG. 4 is a flow chart showing processing when suppressing non-interference control. FIG. 5 is a diagram showing waveforms when non-interference control is suppressed. FIG. 6 is a diagram showing waveforms in a comparative example.

Hereinafter, a vehicle control device according to an embodiment of the present invention will be specifically described with reference to the drawings. In addition, this invention is not limited to embodiment described below.

FIG. 1 is a diagram schematically showing the configuration of a vehicle according to an embodiment. A vehicle 1 includes a DC power supply 2 , an inverter 3 , a motor 4 , driving wheels 5 and a control device 10 . This vehicle 1 is an electric vehicle using a motor 4 as a power source, and the motor 4 drives drive wheels 5 . A motor drive system of the vehicle 1 includes a DC power supply 2 , an inverter 3 and a motor 4 .

The DC power supply 2 is a power storage device capable of storing power to be supplied to the motor 4 . This DC power supply 2 is composed of a secondary battery such as a nickel-hydrogen battery or a lithium-ion battery.

The inverter 3 is a power conversion device that converts the DC power supplied from the DC power supply 2 into AC power and outputs the AC power to the motor 4 . The inverter 3 includes six switching elements and six diodes connected in parallel in opposite directions to the respective switching elements so that three-phase currents can flow through the three-phase coils of the motor 4 . Each switching element is composed of an IGBT or the like. The inverter 3 is controlled by the control device 10 and converts the DC power into the AC power by the switching operation of the switching element for each phase (U-phase, V-phase, W-phase). At that time, the inverter 3 applies a three-phase voltage to the motor 4 according to the three-phase voltage command from the control device 10 .

The motor 4 is a power source for running, and is a three-phase AC motor with permanent magnets embedded in the rotor. In the motor 4, three-phase currents flow according to the three-phase voltages applied to the coils of each phase, and torque is generated. This motor 4 is mechanically connected to drive wheels 5 and is capable of generating torque for driving the vehicle 1 . When the vehicle 1 is braked, the motor 4 can receive input of kinetic energy of the vehicle 1 and regenerate (generate power).

When the inverter 3 applies a three-phase voltage to the motor 4 , a current (phase current) flows through each phase coil of the motor 4 . The phase current includes a U-phase current flowing through the U-phase coil of the motor 4 , a V-phase current flowing through the V-phase coil of the motor 4 , and a W-phase current flowing through the W-phase coil of the motor 4 .

The control device 10 is an electronic control device that controls the operation of the inverter 3 . This electronic control unit includes a microcomputer having a CPU, a RAM, a ROM, and an input/output interface. The control device 10 performs signal processing according to a program pre-stored in the ROM. Signals from various sensors are input to the control device 10 . Signals input to the control device 10 include a phase current from a current sensor that detects the phase current of the motor 4 and a rotation angle θ from a rotation angle sensor 6 that detects the rotation angle θ of the motor 4. can. The control device 10 executes various controls based on signals input from various sensors. For example, the control device 10 calculates the electrical angle θe, the electrical angular velocity ωe, and the rotation speed Nm of the motor 4 based on the rotation angle θ of the motor 4 input from the rotation angle sensor 6 .

In the vehicle 1 , power output from the motor 4 is transmitted to the drive wheels 5 via the power transmission mechanism 20 . A power transmission mechanism 20 is arranged between the motor 4 and the drive wheels 5 to form a power transmission path therebetween. The power transmission mechanism 20 includes a rotating shaft 21 connected to the output shaft of the motor 4 , a differential gear mechanism 22 and a drive shaft 23 . The motor 4 drives the drive wheels 5 through the power transmission mechanism 20 . Furthermore, a load is mechanically connected to the output shaft of the motor 4 while the motor 4 and the drive wheels 5 are connected so as to be able to transmit power. This load may include a dynamo in addition to the power transmission mechanism 20 .

When the drive wheels 5 are driven by the motor 4 , the control device 10 performs drive control so that the motor 4 outputs torque corresponding to the torque command value Tr ^* . The torque command value Tr ^* is set based on the accelerator opening and the vehicle speed. This torque command value Tr ^* is calculated by an electronic control device other than the control device 10, for example, a host ECU such as a vehicle controller. The vehicle controller receives an accelerator opening signal from an accelerator opening sensor that detects the depression amount of an accelerator pedal and a vehicle speed signal from a vehicle speed sensor that detects the vehicle speed of the vehicle 1 . Then, the vehicle controller calculates the required driving force based on the accelerator opening and the vehicle speed, and calculates the required torque according to the required driving force. Further, the vehicle controller sets the required torque to the torque command value Tr ^* of the motor 4 and outputs the torque command value Tr ^* to the control device 10 . Therefore, a torque command value Tr ^* determined according to the depression amount of the accelerator pedal is input to the control device 10 .

The control device 10 controls the voltage and current applied to the motor 4 by controlling the inverter 3 so that the motor 4 outputs a torque corresponding to the torque command value Tr ^* . At that time, the control device 10 controls the output torque of the motor 4 by controlling the operation of each switching element of the inverter 3 . In short, the control device 10 generates a switching signal G according to the torque command value Tr ^* , outputs it to the inverter 3, and executes switching control for controlling the operation of each switching element of the inverter 3. FIG. Each switching element of the inverter 3 performs a switching operation between ON and OFF according to the switching signal G. FIG.

Further, the control device 10 is configured to suppress heat generation of the switching elements of the inverter 3 in a state where the output shaft of the motor 4 is mechanically restrained from the load side (hereinafter referred to as a locked state). When the motor 4 is locked, the phase current is concentrated in only one phase, and the switching element of that phase may become overheated. Therefore, when control device 10 detects that motor 4 is in the locked state, control device 10 executes current distribution control as control for suppressing heat generation in the switching elements of inverter 3 .

Current distribution control is control that vibrates the motor torque at the torsional resonance frequency of the power transmission mechanism 20 . By executing the current dispersion control by the control device 10, the power transmission mechanism 20 is twisted and the rotor of the motor 4 rotates even in the locked state.

More specifically, the vehicle 1 has resonance characteristics due to torsion of the power transmission mechanism 20 . The torsional resonance frequency is determined by the inertia of motor 4 and the torsional rigidity of power transmission mechanism 20 . For example, the torsional resonance frequency of drive shaft 23 is determined by the inertia of motor 4 and the torsional rigidity of drive shaft 23 . Then, the control device 10 executes current dispersion control to generate a slight torque fluctuation within a practical error range, that is, slightly oscillate the output torque of the motor 4 alternately in the positive direction and the negative direction, so that the motor 4 Rotate the rotor slightly alternately in the positive and negative directions. As the rotor of the motor 4 alternately rotates positively and negatively slightly, the phase currents flow in three phases in a dispersed manner. As a result, the current, which may be concentrated in one phase, can be distributed substantially evenly to the three phases, and heat generation of the switching elements of the inverter 3 can be suppressed.

Furthermore, the findings of the present inventors have revealed that an overcurrent occurs in the phase current of the motor 4 when the current distribution control is executed. In addition, the inventors have clarified that the overcurrent that occurs during current distribution control is caused by non-interference control in motor control. In other words, although the current dispersion control is being executed to suppress the heat generation of the switching elements of the inverter 3, the non-interference control is executed while the current dispersion control is being executed. heat generation occurs. This non-interference control is non-interference control of a current feedback system, and is control for canceling mutual interference components according to the d-axis current command value _{Id_cmd} and the q-axis current command value _{Iq_cmd} . Therefore, the control device 10 is configured to perform control for suppressing the non-interference control of the current feedback system (hereinafter referred to as suppression control) when executing the current dispersion control. Therefore, control device 10 executes suppression control as well as current distribution control as control for suppressing heat generation in the switching elements of inverter 3 when motor 4 is in the locked state.

Specifically, the control device 10 includes a lock detection section 11 that detects a locked state of the motor 4 and a control section 12 that controls the output torque of the motor 4 .

A lock detector 11 detects that the motor 4 is locked based on the rotation angle θ from the rotation angle sensor 6 . The lock detector 11 determines that the motor 4 is in the locked state when the lock determination condition is satisfied. The lock determination condition is determined to be satisfied when the state in which the rotation speed Nm of the motor 4 is equal to or less than a predetermined rotation speed and the torque command value Tr ^* of the motor 4 exceeds a predetermined torque continues for a predetermined time. When the lock detector 11 determines that the motor 4 is in the locked state, the lock detector 11 outputs a signal indicating the locked state to the controller 12 .

The control unit 12 controls the inverter 3 to cause the motor 4 to output torque corresponding to the torque command value Tr ^* . The control unit 12 generates a switching signal G according to the torque command value Tr ^* and outputs it to the inverter 3 . Further, the control section 12 can detect the locked state based on the signal from the lock detection section 11 . Then, when the motor 4 is in the locked state, the control unit 12 executes current distribution control and suppression control to suppress heat generation in the switching elements of the inverter 3 .

FIG. 2 is a block diagram showing the configuration of the control unit. The control unit 12 includes a current distribution control unit 12a and a torque control unit 12b. A torque command value Tr ^* input from the vehicle controller to the control device 10 is supplied to the torque control section 12b via the current distribution control section 12a.

The current distribution control unit 12a executes current distribution control in the locked state. The current distribution control unit 12a has a torque fluctuation generator 31, a switch 32, and an adder 33.

Torque fluctuation generator 31 outputs fluctuation torque ΔTr that changes at the torsional resonance frequency of power transmission mechanism 20 . The fluctuating torque ΔTr rotates the rotor of the motor 4 alternately in the positive direction and the negative direction, and can cause the rotor to change the electrical angle enough to distribute the current concentrated in one phase evenly among the three phases. is set to a suitable size. In addition, the fluctuating torque ΔTr is torque that is absorbed by the torsion of the power transmission mechanism 20 and is not transmitted to the driving wheels 5 . Note that the fluctuating torque ΔTr may change at a frequency near the torsional resonance frequency.

The switch 32 switches between an ON state (closed state) in which the torque fluctuation ΔTr from the torque fluctuation generator 31 is output to the adder 33 and an OFF state (open state) in which the torque is not output. This switch 32 is turned on when it is in the locked state, and is turned off when it is not in the locked state. When the lock detector 11 detects the locked state, the switch 32 is turned on and the fluctuating torque ΔTr is output to the adder 33 . If the locked state is not detected, the switch 32 is turned off and the fluctuating torque ΔTr is not output to the adder 33 .

The adder 33 adds the fluctuation torque ΔTr to the torque command value Tr ^* . In the locked state, the adder 33 adds the fluctuation torque ΔTr to the torque command value Tr ^* and outputs the result to the torque control section 12b. If it is not in the locked state, the adder 33 outputs the torque command value Tr ^* directly to the torque control section 12b without adding the fluctuation torque ΔTr.

The torque control unit 12b executes drive control according to the torque command value Tr ^* input from the current dispersion control unit 12a. The torque control unit 12b includes a current command generation unit 41, a three-phase/dq-axis conversion unit 42, a PI control unit 43, a non-interference controller 44, suppression units 45 and 46, subtractors 47 and 48, It has a dq axis/three-phase converter 49 and a PWM signal converter 50 .

The current command generation unit 41 generates a d-axis current command value I _{d_cmd} and a q-axis current command value I _{q_cmd} according to the torque command value Tr ^* , and outputs them to the PI control unit 43 and the non-interference controller 44 . This torque command value Tr ^* is a torque command value corresponding to the depression amount of the accelerator pedal, and is a torque command value to which the fluctuation torque ΔTr is added when the motor 4 is locked. If it is not in the state, it is a torque command value to which the fluctuating torque ΔTr has not been added.

Three-phase/dq-axis converter 42 converts V-phase current iv and W-phase current iw into d-axis current id and q-axis current iq based on electrical angle θe, and outputs them to PI controller 43 . The three-phase/dq-axis converter 42 receives the V-phase current iv and W-phase current iw of the motor 4 detected by the current sensor, and the electrical angle θe calculated based on the rotation angle θ from the rotation angle sensor 6. is entered.

The PI control _{unit 43} performs PI _{calculation (} proportional integral calculation) to output the d-axis voltage command value and the q-axis voltage command value. A d-axis current _id and a q-axis current _iq are input to the PI control unit 43 as feedback information. Then, the PI control unit 43 calculates the deviation of the measured value from the current command value, outputs the d-axis voltage command value to the subtractor 47 and outputs the q-axis voltage command value to the subtractor 48 .

The non-interference controller 44 is a control term for executing non-interference control. The non-interference controller 44 calculates the mutual interference component based on the d-axis current command value _{Id_cmd} and the q-axis current command value _{Iq_cmd} , and outputs the mutual interference component to the suppression units 45 and 46 . A d-axis current command value I _{d_cmd} , a q-axis current command value I _{q_cmd} , a d-axis inductance L _d , a q-axis inductance L _q , and an electrical angular velocity ωe are input to the non-interference controller 44 . The d-axis inductance _Ld and the q-axis inductance _Lq are set based on the inductance map. In the torque controller 12b, the current command generator 41 outputs the d-axis current command value _{Id_cmd} and the q-axis current command value _{Iq_cmd} to the inductance map. The inductance map is a table for outputting the d-axis inductance _Ld corresponding to the d-axis current command value _{Id_cmd} and the q-axis inductance _Lq corresponding to the q-axis current command value _{Iq_cmd} .

The suppression units 45 and 46 are control terms for suppressing non-interference control. The suppression units 45 and 46 selectively suppress mutual interference components from the non-interference controller 44 . The control unit 12 disables the non-interference control when suppressing the non-interference control. Therefore, since the non-interference control is disabled in the locked state, the mutual interference components output from the non-interference controller 44 are blocked by the suppressors 45 and 46 and are not input to the subtractors 47 and 48 . Since the non-interference control is not suppressed when not in the locked state, the mutual interference components output from the non-interference controller 44 are input to the subtractors 47 and 48 via the suppressors 45 and 46 .

Here, the PI controller 43, the non-interference controller 44, the suppressors 45 and 46, and the subtractors 47 and 48 will be described in more detail with reference to FIG.

The PI controller 43 has a subtractor 43a, a PI controller 43b, a subtractor 43c, and a PI controller 43d. The subtractor 43a subtracts the d-axis current _id from the d-axis current command value _{Id_cmd} and outputs the deviation between the d-axis current command value _{Id_cmd} and the d-axis current _id to the PI controller 43b. The PI controller 43 b performs a PI calculation on the output from the subtractor 43 a with a predetermined gain and outputs a d-axis voltage command value to the subtractor 47 . The subtractor 43c subtracts the q-axis current _iq from the q-axis current command value _{Iq_cmd} and outputs the deviation between the q-axis current command value _{Iq_cmd} and the q-axis current _iq to the PI controller 43d. The PI controller 43 d performs PI calculation on the output from the subtractor 43 c with a predetermined gain and outputs the q-axis voltage command value to the subtractor 48 .

The non-interference controller 44 has multipliers 44a, 44b, 44c, an adder 44d, and a multiplier 44e. In the non-interference controller 44, the d-axis interference component is calculated by the multipliers 44a and 44b, and the q-axis interference component is calculated by the multiplier 44c, the adder 44d and the multiplier 44e.

The multiplier 44a multiplies the d-axis current command value _{Id_cmd} by the d-axis inductance _Ld , and outputs _{Id_cmd} × _Ld to the multiplier 44b. The multiplier 44 b multiplies the output from the multiplier 44 a by the electrical angular velocity ωe, and outputs I _{d_cmd} ×L _d ×ωe, which is the d-axis interference component, to the suppression unit 46 .

The multiplier 44c multiplies the q-axis current command value I _{q_cmd} by the q-axis inductance L _q , and outputs I _{q_cmd} ×L _q to the adder 44d. The adder 44d adds the flux linkage number φ to the output from the multiplier 44c and outputs I _{q_cmd} ×L _q +φ to the multiplier 44e. The multiplier 44 e multiplies the output from the adder 44 d by the electrical angular velocity ωe, and outputs the q-axis interference component (I _{q_cmd} ×L _q +φ) ωe to the suppression unit 45 .

The suppression unit 45 suppresses the q-axis interference component from the non-interference controller 44 . The control unit 12 disables the non-interference control when suppressing the non-interference control. That is, when suppressing the non-interference control, the suppression unit 45 functions so as not to output the q-axis interference component from the non-interference controller 44 to the subtractor 47 . On the other hand, when the non-interference control is not suppressed, the suppression unit 45 outputs the q-axis interference component from the non-interference controller 44 to the subtractor 47 .

The suppression unit 46 suppresses the d-axis interference component from the non-interference controller 44 . This suppressor 46 functions similarly to the suppressor 45 . That is, when suppressing the non-interference control, the suppression unit 46 functions so as not to output the d-axis interference component from the non-interference controller 44 to the subtractor 48 . On the other hand, when the non-interference control is not suppressed, the suppression unit 46 outputs the d-axis interference component from the non-interference controller 44 to the subtractor 48 .

The subtractor 47 subtracts the q-axis interference component from the suppression unit 45 from the d-axis voltage command value from the PI control unit 43, and outputs the d-axis voltage command value _Vd to the dq-axis/three-phase conversion unit 49. . When suppressing the non-interference control, since there is no input from the suppression unit 45, the subtractor 47 outputs the d-axis voltage command value from the PI control unit 43 as it is as the d-axis voltage command value _Vd . On the other hand, when the non-interference control is not suppressed, there is an input from the suppression unit 45, so the subtractor 47 subtracts the q-axis interference component from the d-axis voltage command value from the PI control unit 43, and converts the value to the d-axis voltage. Output as command value _Vd .

The subtractor 48 subtracts the d-axis interference component from the suppression unit 46 from the q-axis voltage command value from the PI control unit 43 and outputs the q-axis voltage command value _Vq to the dq-axis/three-phase conversion unit 49. . When suppressing the non-interference control, since there is no input from the suppression unit 46, the subtractor 48 outputs the q-axis voltage command value from the PI control unit 43 as it is as the q-axis voltage command value _Vq . On the other hand, when the non-interference control is not suppressed, there is an input from the suppression unit 46, so the subtractor 48 subtracts the d-axis interference component from the q-axis voltage command value from the PI control unit 43, and converts the value to the q-axis voltage. Output as command value V _q .

Return to FIG. A dq-axis/three-phase converter 49 generates three-phase voltage command values Vu, Vv, and Vw based on the d-axis voltage command value _Vd , the q-axis voltage command value _Vq , and the electrical angular velocity ωe, and converts them to PWM signals. Output to the conversion unit 50 .

The PWM signal converter 50 converts the switching signals Gu, Gv, Gw in the respective phase switching elements of the inverter 3 based on the three-phase voltage command values Vu, Vv, Vw input from the dq-axis/three-phase converter 49. Generate. The switching signals Gu, Gv, and Gw are command signals for switching ON and OFF of the switching elements. The PWM signal converter 50 outputs the switching signals Gu, Gv, Gw of each phase to the inverter 3 .

FIG. 4 is a flow chart showing processing when suppressing non-interference control. The control shown in FIG. 4 is performed by the control device 10 .

The control device 10 determines whether or not the motor 4 is locked (step S101). In step S101, it is determined whether or not the lock detection unit 11 has detected the locked state of the motor 4 .

When it is determined that the motor 4 is in the locked state (step S101: Yes), the control device 10 suppresses non-interference control (step S102) and implements current dispersion control (step S103).

In step S102, mutual interference components corresponding to the d-axis current command value _{Id_cmd} and the q-axis current command value _{Iq_cmd} are suppressed. When the control device 10 suppresses the non-interference control, it disables the non-interference control, and the mutual interference components calculated by the non-interference controller 44 are blocked by the suppression units 45 and 46. No interference component is input, and no d-axis interference component is input to the subtractor 48 .

In step S<b>103 , control is executed to oscillate the motor torque at the torsional resonance frequency of the power transmission mechanism 20 . In other words, the control of adding the torque command value Tr* to the torque command value Tr ^* is performed by the current distribution control unit 12a. In this case, the switch 32 is turned on and the fluctuating torque ΔTr from the torque fluctuation generator 31 is input to the adder 33. Therefore, the torque obtained by adding the fluctuating torque ΔTr to the torque command value Tr ^* corresponding to the depression amount of the accelerator pedal A command value is input to the torque control unit 12b. Therefore, when the process of step S103 is performed, the control unit 12 controls the motor torque so as to cause the power transmission mechanism 20 to twist. After executing the process of step S103, the control routine returns to step S101.

When it is determined that the motor 4 is not locked (step S101: No), the control device 10 turns on non-interference control (step S104). In step S104, the mutual interference component from the non-interference controller 44 is input to the subtractors 47 and 48 because the non-interference control is not suppressed or the suppression of the non-interference control is cancelled. After performing the process of step S104, this control routine ends.

FIG. 5 is a diagram showing waveforms when non-interference control is suppressed. FIG. 6 is a diagram showing waveforms in a comparative example.

Each waveform shown in FIG. 5 indicates the result of actual device verification of the control of the embodiment. In the actual machine verification, the motor 4, transaxle, drive shaft 23, and dynamo (load) were mechanically connected to measure the behavior during current distribution control. In the conventional configuration shown in FIG. 6, non-interference control is performed only when the rotor rotates forward, and it can be seen that an overcurrent occurs in the phase current due to sudden fluctuations in the motor electrical angle during forward rotation. As shown in FIG. 6, no overcurrent occurs during reverse rotation. On the other hand, in the embodiment, as shown in FIG. 5, by invalidating the non-interference control term on the forward rotation side as well, even if the motor electrical angle suddenly fluctuates, no overcurrent occurs in the phase current. I understand.

As described above, according to the embodiment, when the motor 4 is in the locked state, by suppressing the non-interference control of the current feedback system during the control for vibrating the motor torque and causing the torsion of the power transmission mechanism 20, It is possible to suppress the occurrence of overcurrent. Thereby, heat generation in the switching elements of the inverter 3 can be suppressed. In addition, control stability can be ensured. Therefore, the element size of the switching element of the inverter 3 can be reduced.

Further, the control device 10 is not limited to a configuration that disables non-interference control when suppressing non-interference control. In other words, as long as the non-interference control can be suppressed compared to the case where the non-interference control is not suppressed, it does not necessarily have to be invalidated. In this case, it is taken into consideration that the rotational speed Nm of the motor 4 momentarily increases due to the twisting of the power transmission mechanism 20 . Since the non-interference control outputs a correction amount (a correction amount to the d-axis voltage command value and the q-axis voltage command value) proportional to the rotation speed Nm (electrical angular velocity ωe), the "d The amount of correction to the axis voltage command value and the q-axis voltage command value” becomes large. Therefore, in order to prevent the non-interference control term from increasing even if the rotation speed Nm increases momentarily due to twisting, a configuration (first modification) that reduces the non-interference control by a predetermined ratio, or the upper and lower limits of the non-interference control is provided (second modification).

When suppressing non-interference control, the control device 10 of the first modification reduces the non-interference control to a constant rate. For example, the non-interference control term is multiplied by a coefficient m (0<m<1) to reduce it. In the first modified example, the "correction amount to the d-axis voltage command value and the q-axis voltage command value", which is the calculation result of the non-interference control, is reduced by a predetermined ratio by the coefficient m. The suppression units 45 and 46 of the first modified example do not set the correction amount by the non-interference control to zero, but continue to output the correction amount to the subtractors 47 and 48 in a reduced state. If the non-interference control is disabled and the correction amount is set to zero in the locked state as in the embodiment, a sudden change in which a large correction amount is suddenly applied may occur immediately after switching from the locked state to normal motor control. On the other hand, in the first modified example, since the correction amount by the non-interference control is continuously output even in the locked state, it is possible to alleviate the sudden change immediately after switching from the locked state to the normal motor state. As described above, in the first modified example, controllability is stabilized when switching from the locked state to the normal motor control as compared with the invalidation method.

The control device 10 of the second modified example sets the upper limit value and the lower limit value of the non-interference control so that an overcurrent does not occur in the phase current when suppressing the non-interference control. In the second modification, an upper limit value and a lower limit value are set for the "correction amount to the d-axis voltage command value and the q-axis voltage command value" which is the calculation result of the non-interference control. The suppression units 45 and 46 of the second modification do not set the correction amount by the non-interference control to zero, and continue to output the correction amount to the subtractors 47 and 48 within the range from the upper limit value to the lower limit value. The upper limit value and the lower limit value are set to values that stabilize the controllability even if the correction amount of the non-interference control is directly output to the subtractors 47 and 48 when the locked state shifts to the normal motor control. . For example, the correction amount is limited to ±3% with respect to the uncorrected d-axis voltage command value and q-axis voltage command value calculated by the PI control unit 43 . When normal motor control is resumed after disabling non-interference control or reducing it by a predetermined rate, the non-interference control term increases discontinuously, and the control may become unstable. On the other hand, in the second modification, if the magnitude of the correction amount of the non-interference control is within the range from the upper limit value to the lower limit value, when the normal motor control is restored, the correction amount remains unchanged. Since it is inherited, the control does not become unstable. In this way, in the second modification, the non-interference control term becomes continuous when shifting from the locked state to the normal motor control. .

Furthermore, in the second modified example, regarding the upper and lower limits of the non-interference control, by narrowing the width from the upper limit value to the lower limit value, the correction amount by the non-interaction control can be reduced, and if the width is widened, even a large correction amount is allowed. do. That is, the control device 10 of the second modification can strengthen or weaken the effect of the non-interference control by controlling the upper limit value and the lower limit value of the non-interference control.

REFERENCE SIGNS LIST 1 vehicle 2 DC power supply 3 inverter 4 motor 5 drive wheel 6 rotation angle sensor 10 control device 11 lock detection unit 12 control unit 12a current distribution control unit 12b torque control unit 20 power transmission mechanism 23 drive shaft

Claims (5)

a rotating electrical machine that drives the drive wheels via a power transmission mechanism;
a power conversion device that converts DC power into AC power using a switching element and supplies the power to the rotating electric machine;
a control unit that controls the electric power conversion device to perform drive control that causes the rotating electrical machine to output a torque corresponding to a torque command value determined according to the amount of depression of an accelerator pedal;
a lock detection unit that detects that the output shaft of the rotating electrical machine is in a locked state in which the output shaft is mechanically restrained from the load side;
A control device for a vehicle comprising
When the locked state is detected by the lock detection unit, the control unit suppresses non-interference control of the current feedback system compared to when the locked state is not detected, and changes the torque command value to the torque command value. A control device for a vehicle, characterized by changing at a predetermined frequency only the amount of change absorbed by torsion of a power transmission mechanism. The vehicle control device according to claim 1, wherein the predetermined frequency is a torsional resonance frequency of the power transmission mechanism. The vehicle control device according to claim 1 or 2, wherein the control unit disables the non-interference control when suppressing the non-interference control. 3. The non-interference control according to claim 1, wherein when suppressing the non-interference control, the control unit performs the non-interference control by reducing it by a predetermined ratio compared to when the locked state is not detected. Vehicle controller. The vehicle control according to any one of claims 1 to 4, wherein the control unit limits an upper limit value and a lower limit value of the non-interference control when suppressing the non-interference control. Device.

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