Motor drive apparatus, method for controlling the same, vehicle, and readable storage medium

1. A motor drive apparatus, comprising: a three-phase inverter, a three-phase motor, and a buck side capacitor connected in sequence, wherein the buck side capacitor is connected to a positive electrode and a negative electrode of a power supply module, a first terminal of the three-phase inverter is connected to a positive electrode of a power battery, a second terminal of the three-phase inverter is connected to a negative electrode of the power battery, a first terminal of the buck side capacitor is connected to a connection point of three phase coils of the three-phase motor, a second terminal of the buck side capacitor is connected to the second terminal of the three-phase inverter, and the three phase coils of the three-phase motor are respectively connected to midpoints of three phase legs of the three-phase inverter, wherein the motor drive apparatus is configured to simultaneously control a process of charging the power battery by the power supply module, a torque of the three-phase motor at a zero output, and the three-phase inverter, and the three-phase motor to heat a heat exchange medium flowing through at least one of the three-phase inverter or the three-phase motor.

2. The motor drive apparatus according to claim 1 , further comprising an inductor, wherein the inductor is connected between the connection point of the three phase coils of the three-phase motor and the first terminal of the buck side capacitor.

3. The motor drive apparatus according to claim 1 , wherein the motor drive apparatus is further configured to perform operations comprising:

obtaining a required heating power and a required charging power; and

adjusting a current value and direction of each phase current of the three-phase motor based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque.

4. The motor drive apparatus according to claim 1 , wherein the motor drive apparatus is further configured to perform operations comprising:

obtaining a required heating power and a required charging power;

obtaining a target input current of the three-phase motor and a first target duty cycle of a control pulse of each phase leg based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque; and

receiving an input current of the power supply module based on the target input current, and controlling each phase leg based on the first target duty cycle.

5. The motor drive apparatus according to claim 4 , wherein the obtaining a target input current of the three-phase motor and a first target duty cycle of a control pulse of each phase leg based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque comprises:

obtaining a target voltage of the buck side capacitor; and

calculating the target input current of the three-phase motor based on the required heating power, the required charging power, the output of the three-phase motor at a zero torque, and the target voltage.

6. The motor drive apparatus according to claim 5 , wherein the obtaining a target input current of the three-phase motor and a first target duty cycle of a control pulse of each phase leg based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque further comprises:

obtaining a target current of each phase current of the three-phase motor based on a location of a motor rotor, the required heating power, the target input current, and the output of the three-phase motor at a zero torque; and

obtaining the first target duty cycle of the control pulse of each phase leg based on the target current of each phase current, the target input current, the target voltage of the buck side capacitor, and a voltage of the power battery.

7. The motor drive apparatus according to claim 6 , wherein the obtaining a target current of each phase current based on a location of a motor rotor, the required heating power, the target input current, and the output of the three-phase motor at a zero torque comprises:

calculating a target current of each phase current of the three-phase motor based on the required heating power, the location of the motor rotor, and the output of the three-phase motor at a zero torque by using formula 1, formula 2, and formula 3:

T e =3/2*ρ*[λ+( L d −L q )*⅔*[sin α* IA +sin(α−120)* IB +sin(α+120)* IC ]]*⅔*(cos α* IA +cos(α−120)* IB +cos(α+120)* IC ),  Formula 1

IA+IB+IC=I,   Formula 2

P =( IA×IA+IB×IB+IC×IC )× R,   Formula 3

wherein α is a lag angle of a rotor, IA, IB, and IC are respectively phase currents of the three phase coils, I is the target input current, Te is the output of the three-phase motor at a zero torque, λ, ρ, L d , L q are motor parameters, P is heating power, and R is an equivalent impedance of the three-phase motor.

8. The motor drive apparatus according to claim 6 , wherein the obtaining the first target duty cycle of the control pulse of each phase leg based on the target current of each phase current, the target input current, the target voltage of the buck side capacitor, and a voltage of the power battery comprises:

obtaining an average duty cycle of control pulses of three phase currents based on the target voltage of the buck side capacitor, the target input current, and the voltage of the power battery; and

obtaining the first target duty cycle of the control pulse of each phase leg based on the average duty cycle, the target input current, the target current of each phase current, and the voltage of the power battery.

9. The motor drive apparatus according to claim 8 , wherein the obtaining an average duty cycle of control pulses of three phase currents based on the target voltage of the buck side capacitor, the target input current, and the voltage of the power battery comprises:

obtaining the average duty cycle of the control pulses of the three phase currents based on the target voltage of the buck side capacitor, the target input current, and the voltage of the power battery by using a formula:

U 2 =U 1 ×D 0 −I×R,

wherein U 2 is the target voltage of the buck side capacitor, U 1 is the voltage of the power battery, D 0 is the average duty cycle of the control pulses of the three phase currents, I is the target input current, and R is an equivalent impedance of the three-phase motor; and

obtaining the first target duty cycle of the control pulse of each phase leg based on the average duty cycle, the target input current, the target current of each phase current, and the voltage of the power battery by using the following formula:

D

1

=

D

0

-

I

⁢

R

-

I

1

×

R

1

U

1

,

wherein I 1 is the target current of each phase current, R 1 is an equivalent impedance of each phase coil, and D 1 is the first target duty cycle of the control pulse of each phase leg.

10. The motor drive apparatus according to claim 8 , wherein the motor drive apparatus further comprises an inductor; and

the obtaining an average duty cycle of control pulses of three phase currents based on the target voltage of the buck side capacitor, the target input current, and the voltage of the power battery comprises:

obtaining the average duty cycle of the control pulses of the three phase currents based on the target voltage of the buck side capacitor, the target input current, and the voltage of the power battery by using a formula:

U 2 =U 1 ×D 0 −I×R−I×R L ,

wherein U 2 is the target voltage of the buck side capacitor, U 1 is the voltage of the power battery, D 0 is the average duty cycle of the control pulses of the three phase currents, I is the target input current, R is an equivalent impedance of the three-phase motor, and R L is an impedance of the inductor; and

obtaining the first target duty cycle of the control pulse of each phase leg based on the average duty cycle, the target input current, the target current of each phase current, and the voltage of the power battery by using the following formula:

D

1

=

D

0

-

I

⁢

R

-

I

1

×

R

1

U

1

,

wherein I 1 is the target current of each phase current, R 1 is an equivalent impedance of each phase coil, and D 1 is the first target duty cycle of the control pulse of each phase leg.

11. The motor drive apparatus according to claim 4 , wherein after the controlling each phase leg based on the first target duty cycle, the operations further comprise:

obtaining an actual input current of the three-phase motor, and performing a proportional-integral-derivative (PID) control operation based on the actual input current and the target input current of the three-phase motor by using a PID regulator to obtain a variation of an average duty cycle of control pulses of three phase currents;

obtaining a second target duty cycle based on the first target duty cycle and the variation of the average duty cycle; and

controlling each phase leg based on the second target duty cycle, to simultaneously control the process of charging the power battery by the power supply module, the torque of the three-phase motor at a zero output, and the three-phase inverter and the three-phase motor to heat a heat exchange medium flowing through at least one of the three-phase inverter or the three-phase motor.

12. The motor drive apparatus according to claim 11 , wherein the obtaining an actual input current of the three-phase motor, and performing a PID control operation based on the actual input current and the target input current of the three-phase motor by using a PID regulator to obtain a variation of the average duty cycle of the control pulses of the three phase currents comprises:

obtaining a current difference between the actual input current and the target input current of the three-phase motor; and

when the actual input current of the three-phase motor is greater than the target input current, calculating an increase in the average duty cycle of the control pulses of the three phase currents based on the current difference and a proportional coefficient of the PID regulator; or

when the actual input current of the three-phase motor is less than the target input current, calculating a decrease in the average duty cycle of the control pulses of the three phase currents based on a current difference and a proportional coefficient of the PID regulator.

13. The motor drive apparatus according to claim 4 , wherein after the controlling each phase leg based on the first target duty cycle, the operations further comprise:

obtaining an actual current of each phase current, and performing a PID control operation based on the actual current and a target current of each phase current by using a PID regulator to obtain a variation of a duty cycle of the control pulse of each phase leg;

obtaining a third target duty cycle based on the first target duty cycle and the variation of the duty cycle; and

controlling each phase leg based on the third target duty cycle, to simultaneously control the process of charging the power battery by the power supply module, the torque of the three-phase motor at a zero output, and the three-phase inverter and the three-phase motor to heat the heat exchange medium flowing through at least one of the three-phase inverter or the three-phase motor.

14. The motor drive apparatus according to claim 13 , wherein the performing a PID control operation based on the actual current and the target current of each phase current by using a PID regulator to obtain a variation of a duty cycle of the control pulse of each phase leg comprises:

obtaining a current difference between the actual current and the target current of each phase current;

when the target current of each phase current is greater than the actual current, calculating an increase in the duty cycle of the phase leg based on the current difference and a proportional coefficient of the PID regulator; or

when the target current of each phase current is less than the actual current, calculating a decrease in the duty cycle of the phase leg based on the current difference and a proportional coefficient of the PID regulator.

15. A vehicle, comprising a memory and a processor, wherein

the processor is configured to read an executable program code stored in the memory to run a program corresponding to the executable program code, to perform operations comprising:

obtaining a required heating power and a required charging power; and

adjusting a current value and direction of each phase current of a three-phase motor based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque, to simultaneously control a process of charging a power battery by a power supply module, a torque of the three-phase motor at a zero output, and a three-phase inverter and the three-phase motor to heat a heat exchange medium flowing through at least one of the three-phase inverter or the three-phase motor.

16. The vehicle according to claim 15 , wherein the operations further comprise:

obtaining a required heating power and a required charging power; and

adjusting a current value and direction of each phase current of the three-phase motor based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque.

17. The vehicle according to claim 15 , wherein the operations further comprise:

obtaining a required heating power and a required charging power;

obtaining a target input current of the three-phase motor and a first target duty cycle of a control pulse of each phase leg based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque; and

receiving an input current of the power supply module based on the target input current, and controlling each phase leg based on the first target duty cycle.

18. The vehicle according to claim 17 , wherein the obtaining a target input current of the three-phase motor and a first target duty cycle of a control pulse of each phase leg based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque comprises:

obtaining a target voltage of a buck side capacitor; and

calculating the target input current of the three-phase motor based on the required heating power, the required charging power, the output of the three-phase motor at a zero torque, and the target voltage.

19. The vehicle according to claim 18 , wherein the obtaining a target input current of the three-phase motor and a first target duty cycle of a control pulse of each phase leg based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque further comprises:

obtaining a target current of each phase current of the three-phase motor based on a location of a motor rotor, the required heating power, the target input current, and the output of the three-phase motor at a zero torque; and

obtaining the first target duty cycle of the control pulse of each phase leg based on the target current of each phase current, the target input current, the target voltage of the buck side capacitor, and a voltage of the power battery.

20. A non-transitory computer-readable storage medium, storing a computer program thereon, wherein when the program is executed by a processor, the processor is configured to perform operations comprising:

obtaining a required heating power and a required charging power; and

adjusting a current value and direction of each phase current of a three-phase motor based on the required heating power, the required charging power, and an output of the three-phase motor at a zero torque, to simultaneously control a process of charging a power battery by a power supply module, a torque of the three-phase motor at a zero output, and a three-phase inverter and the three-phase motor to heat a heat exchange medium flowing through at least one of the three-phase inverter or the three-phase motor.