A ripple suppression of sensorless FOC of PMSM electrical drive system based on MRAS

When the PMSM motor rotates at high speed, the motor winding current contains a lot of harmonics, and the harmonic current will increase the heat of the motor, thereby reducing the operating efficiency and service life of the motor. In view of the above problems, in the EV motor control, a rotor speed observer based on model reference adaptation was designed. This method was taken the stator current equation containing rotor position parameters as adjustable model, and the stator current equation of the motor itself as adjustable model. The reference model was designed the adaptive rate based on the Popov superstability theory; at the same time, the feed-forward compensation based on the sliding mode observer was designed to suppress harmonics. The simulation and experimental results have shown that the method can effectively reduce the current harmonics, speed error and torque ripple content of the EV motor compared with the MRAS speed sensorless control.