Method and system for motor torque control of an electric vehicle

Abstract

The invention provides a motor torque control method and system for an electric vehicle. The method comprises the following steps: an Id / Iq table for controlling motor torque output is obtained, torque output by a motor is calibrated according to the Id / Iq table, so that multiple groups of corresponding demanded torque calibrated values Tdemand and executing torque calibrated values Texecute of the motor can be obtained, and values of equation coefficients a, b and c are obtained by calculation according to the torque precision calibration formula: Texecute is equal to aTdemand<2>+bTdemand+c;modified output torque of the motor is obtained according to the torque precision calibration formula and actual demanded torque, and modified Id and Iq corresponding to the modified output torque areobtained through the Id / Iq table; the torque output by the motor is modified by taking Id and Iq as PI closed-loop control parameters of motor output torque. Precision of the torque output by the motor can be improved, and use comfort and safety of the electric vehicle can be improved.

Description

technical field [0001] The invention relates to motor control technology, in particular to a method and system for motor torque control of an electric vehicle. Background technique [0002] The drive system is one of the three core components of electric vehicles, and its performance directly determines the performance of the vehicle. The torque output of the motor is an important index for evaluating the performance of the electric drive system. The index for evaluating the torque output is not only whether the peak torque can be output, but also the accuracy of the torque output. The controller performs closed-loop control on the output torque of the motor. Inaccurate torque output will cause the vehicle to vibrate. Therefore, the accuracy of the motor output torque is required to be high. When the vehicle is accelerating, the motor needs to output peak torque. If the peak torque cannot be reached, it will It will seriously affect the dynamic performance of the vehicle. ...

AI Technical Summary

Problems solved by technology

[0004] The invention provides a motor torque control method and system of an electric vehicle, which solves the phenomenon that the existing electric vehicle is prone to vibration due to inaccurate motor torque output when running at low speed, can improve the accuracy of the motor output torque, and improve the comfort of using the electric vehicle sex and security

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