The current feedforward compensation method for the cogging torque of permanent magnet synchronous motors

The cogging torque is the inherent characteristic of permanent motors with the cogging. The cogging torque reduces the stability of the motor, especially in the status of the low speed. A compensation method based on the current feedforward is proposed in terms with the function between the torque and Q-Current by the method of Space Vector PWM of the permanent magnet synchronous motors. The relation equation between the cogging torque and the rotor angle is obtained by the experimental analysis. And then, the transfer function of the current closed-loop system is obtained by using the experiment data and the system identification method. The cogging torque compensation current is calculated by the forecast for the position of the rotor. The experiment results show that the presented method can effectively improve the stability of the motor speed.