CN-122008902-A - Motor control method for vehicle

CN122008902ACN 122008902 ACN122008902 ACN 122008902ACN-122008902-A

Abstract

The invention discloses a motor control method of a vehicle. The motor control method of the vehicle comprises the steps of obtaining a vehicle operation condition, obtaining a real-time SOC value and a motor torque demand value of a battery when the vehicle operation condition is an energy recovery condition, obtaining first motor current distribution information according to the real-time SOC value and the motor torque demand value, wherein the first motor current distribution information comprises a first d-axis current distribution value and a first q-axis current distribution value, and performing motor control according to the first motor current distribution information. So as to ensure the braking capability of the whole vehicle, reduce the use of mechanical braking and ensure driving experience.

Inventors

MA WENQI
LI CAN
WANG DONG
CAI JUNHUI
Zhong Qiuwen

Assignees

潍柴动力股份有限公司
潍柴新能源动力科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260401

Claims (10)

1. A motor control method of a vehicle, characterized by comprising: acquiring the running condition of a vehicle; when the vehicle operation working condition is an energy recovery working condition, acquiring a real-time SOC value of a battery and a motor torque demand value; Acquiring first motor current distribution information according to the real-time SOC value and the motor torque demand value, wherein the first motor current distribution information comprises a first d-axis current distribution value and a first q-axis current distribution value; And controlling the motor according to the first motor current distribution information.
2. The motor control method of a vehicle according to claim 1, characterized in that acquiring the vehicle operation condition includes: acquiring a motor rotating speed value, a motor torque value, a real-time d-axis current value and a real-time q-axis current value; And when the motor rotating speed value is larger than zero, the motor torque value is smaller than zero, the real-time d-axis current value is smaller than zero and the real-time q-axis current value is smaller than zero, determining that the vehicle operation working condition is an energy recovery working condition.
3. The motor control method of a vehicle according to claim 1, characterized by further comprising, after acquiring the real-time SOC value of the battery and the motor torque demand value: acquiring a preset SOC value; When the real-time SOC value is greater than or equal to the preset SOC value, starting active degradation operation; and when the real-time SOC value is smaller than the preset SOC value, the active degradation operation is not started.
4. The motor control method of the vehicle according to claim 3, characterized in that when the active degradation operation is started, first motor current distribution information including a first d-axis current distribution value and a first q-axis current distribution value is obtained from the real-time SOC value and the motor torque demand value, including: acquiring an SOC degradation coefficient according to the real-time SOC value; Acquiring the allowable maximum weak current value of the motor; determining a first d-axis current distribution value according to the SOC degradation coefficient and the maximum allowable weak current value of the motor; acquiring motor permanent magnet flux linkage, d-axis inductance, q-axis inductance and motor pole pair number; and determining a first q-axis current distribution value according to the motor torque demand value, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance and the motor pole pair number.
5. The motor control method of the vehicle according to claim 4, characterized in that acquiring an SOC degradation coefficient from the real-time SOC value includes: acquiring a preset maximum SOC value and a preset minimum SOC value; And determining an SOC degradation coefficient according to the real-time SOC value, the preset maximum SOC value and the preset minimum SOC value.
6. The motor control method of a vehicle according to claim 5, characterized in that an SOC degradation coefficient is determined from the real-time SOC value, the preset maximum SOC value, and the preset minimum SOC value based on a first formula: ; Wherein k SOC is the SOC degradation coefficient, k SOC E [0,1], SOC is the real-time SOC value, SOC max is the preset maximum SOC value, and SOC min is the preset minimum SOC value.
7. The motor control method of the vehicle according to claim 4, characterized in that a first d-axis current distribution value is determined from the SOC degradation coefficient and the motor allowable maximum weak current value based on a second formula that is: i d =-i dmax ×(1-k soc ); wherein i d is the first d-axis current distribution value, i dmax is the maximum allowable weak current value of the motor, and k SOC is the SOC degradation coefficient.
8. The motor control method of a vehicle according to claim 4, characterized in that a first q-axis current distribution value is determined from the motor torque demand value, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance, and the motor pole pair number based on a third formula: ; wherein i q is the first q-axis current distribution value, and T e is the motor torque demand value; The motor permanent magnet flux linkage is characterized in that L d is the d-axis inductance, L q is the q-axis inductance, and p is the pole pair number of the motor.
9. The motor control method of a vehicle according to claim 3, characterized by further comprising, after the active degradation operation is not turned on: acquiring a preset motor current distribution MAP; determining second motor current distribution information according to the preset motor current distribution MAP, wherein the second motor current distribution information comprises a second d-axis current distribution value and a second q-axis current distribution value; and controlling the motor according to the second motor current distribution information.
10. The motor control method of a vehicle according to claim 1, characterized by further comprising, before motor control according to the first motor current distribution information: Setting a current safety limiting condition, wherein the current safety limiting condition meets I d 2 +i q 2 ≤I max 2 and I q |＜I chargemax , I d is the first d-axis current distribution value, I q is the first q-axis current distribution value, I max is a preset maximum current amplitude, and I chargemax is a preset maximum battery charging current.

Description

Motor control method for vehicle Technical Field The invention relates to the technical field of vehicle control, in particular to a motor control method of a vehicle. Background At present, when the SOC of a battery of a new energy vehicle approaches to an upper limit, a traditional strategy directly limits the feeding current of a motor to zero or an extremely low value, the motor cannot output negative torque through feeding, so that a regenerative braking function cannot be disabled, braking torque cannot be provided, the vehicle brakes completely depend on a mechanical braking system, mechanical parts are worn and accelerated, maintenance cost is increased, and if the feeding current is suddenly limited or cut off, the braking torque is suddenly reduced, mechanical braking is required to be urgently compensated, braking force is nonlinear, and driving smoothness is affected. Disclosure of Invention The invention provides a motor control method of a vehicle, which is used for ensuring the braking capability of the whole vehicle, reducing the use of mechanical braking and ensuring driving experience. In a first aspect, the present invention provides a motor control method of a vehicle, including: acquiring the running condition of a vehicle; when the vehicle operation working condition is an energy recovery working condition, acquiring a real-time SOC value of a battery and a motor torque demand value; Acquiring first motor current distribution information according to the real-time SOC value and the motor torque demand value, wherein the first motor current distribution information comprises a first d-axis current distribution value and a first q-axis current distribution value; And controlling the motor according to the first motor current distribution information. Optionally, obtaining the vehicle operation condition includes: acquiring a motor rotating speed value, a motor torque value, a real-time d-axis current value and a real-time q-axis current value; And when the motor rotating speed value is larger than zero, the motor torque value is smaller than zero, the real-time d-axis current value is smaller than zero and the real-time q-axis current value is smaller than zero, determining that the vehicle operation working condition is an energy recovery working condition. Optionally, after acquiring the real-time SOC value and the motor torque demand value of the battery, the method further includes: acquiring a preset SOC value; When the real-time SOC value is greater than or equal to the preset SOC value, starting active degradation operation; and when the real-time SOC value is smaller than the preset SOC value, the active degradation operation is not started. Optionally, when the active degradation operation is started, first motor current distribution information is obtained according to the real-time SOC value and the motor torque demand value, the first motor current distribution information including a first d-axis current distribution value and a first q-axis current distribution value includes: acquiring an SOC degradation coefficient according to the real-time SOC value; Acquiring the allowable maximum weak current value of the motor; determining a first d-axis current distribution value according to the SOC degradation coefficient and the maximum allowable weak current value of the motor; acquiring motor permanent magnet flux linkage, d-axis inductance, q-axis inductance and motor pole pair number; and determining a first q-axis current distribution value according to the motor torque demand value, the motor permanent magnet flux linkage, the d-axis inductance, the q-axis inductance and the motor pole pair number. Optionally, acquiring the SOC degradation coefficient according to the real-time SOC value includes: acquiring a preset maximum SOC value and a preset minimum SOC value; And determining an SOC degradation coefficient according to the real-time SOC value, the preset maximum SOC value and the preset minimum SOC value. Optionally, based on a first formula, determining an SOC degradation coefficient according to the real-time SOC value, the preset maximum SOC value and the preset minimum SOC value, where the first formula is: ; Wherein k SOC is the SOC degradation coefficient, k SOC E [0,1], SOC is the real-time SOC value, SOC max is the preset maximum SOC value, and SOC min is the preset minimum SOC value. Optionally, the first d-axis current distribution value is determined according to the SOC degradation coefficient and the motor allowable maximum weak current value based on a second formula, where the second formula is: id=-idmax×(1-ksoc); wherein i d is the first d-axis current distribution value, i dmax is the maximum allowable weak current value of the motor, and k SOC is the SOC degradation coefficient. Optionally, the first q-axis current distribution value is determined according to the motor torque demand value, the motor permanent magnet flux linkage, the d-axis inductan