Torque calibration method for AC induction motor of electric vehicle

Abstract

The invention discloses a torque calibration method for an AC induction motor of an electric vehicle. The torque calibration method comprises the following steps: when the AC induction motor of the electric vehicle controls the electric vehicle, adopting the torque computational formula to convert an expected torque T<o>e into an expected torque current I<0>g, and realizing the torque control according to the directional vector control algorithm of the rotor field; before the torque calibration is carried out, adjusting the time constant parameter Tt and the mutual induction parameter Lm of the motor rotor by comparing the error tendency between an expected torque curve and an actual torque curve, so as to enable the actual torque to be close to the expected torque and to realize the actual torque calibration. According to the torque calibration method, on the basis of the conventional vector control algorithm, by the calibration of the time constant Tt and the mutual induction Lm of the motor rotor based on the conventional motor parameters in sequence, the actual torque calibration is completed; in the entire calibration process, a control motor is smooth and accurate in torque output, the requirement on torque control accuracy of a driving system of the electric vehicle can be met, and cumbersome torque calibration by adopting the table look-at method is further avoided.

Description

technical field [0001] The invention relates to electric vehicle motor control technology, in particular to a torque calibration method for an electric vehicle AC induction motor. Background technique [0002] With the continuous growth of global automobile production and ownership, traditional automobiles have brought about serious environmental pollution and the increasingly urgent global oil resource crisis. "Smoggy weather" and "high oil prices" have made the electric vehicle industry start Flourish. [0003] The power system of an electric vehicle is an electric drive system, and motor control technology is an electric drive system and one of the core technologies of an electric vehicle. At present, the motors used in the electric drive system of electric vehicles mainly include AC induction motors and permanent magnet synchronous motors. Among them, AC induction motors are widely used in electric vehicles due to their high reliability, simple structure, low cost, simp...

AI Technical Summary

Problems solved by technology

However, the AC induction motor is essentially a complex object with multivariable, nonlinear, time-varying parameters, and strong coupling. The electromagnetic parameters such as resistance, inductance, and mutual inductance of each phase winding of the motor are usually difficult to measure or estimate accurately, and are easy to change with temperature changes. , and due to the difference between the motor electromagnetic design parameters and the actual parameters, it is difficult to accurately estimate the rotor magnetic field position, which leads to the error between the torque calculated by the formula method and the actual torque, so how to complete the torque calibration of the AC induction motor and realize the output of the motor Accurate control of torque is the difficulty of electric vehicle motor control

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