Rotor Position Compensation Method for PMSM based on Bus Current Precision Measurement

For permanent magnet synchronous motor (PMSM) control system based on sliding mode observer (SMO), the estimated values of the motor speed and the rotor position is always deviated because of variable of the PMSM parameters in actual operation. The existing optimization method is online parameter identification while the method increases the difficulty of motor control. The accuracy of its identification result directly affects the optimization effect. In order to optimize the observer's performance to obtain the rotor position better, in this paper, the regulator was constructed with rotor position compensation as the control target and the change rate of bus current caused by rotor position error as deviation by deducing the mathematical relationship between rotor position error and bus current of PMSM. Simulation model in MATLAB/Simulink and experiments results in dSPACE show high reliability of the new method and improvement of the motor efficiency.