Sensorless control of permanent magnet synchronous motor based on sliding film observation of load torque

In order to solve the problems of large size, high maintenance cost and unstable performance of the sensor itself in the traditional control method, a non-sensing control method of permanent magnet synchronous motor based on slip film observation of load torque is proposed. The principle of the slip film observer is based on the error between the actual value of the current and the observed value to constitute the synchronous motor counter electromotive force, and thus estimating the actual rotor speed and position. In addition, in order to minimize the influence of system load changes on rotor speed in actual operation, the addition of a load torque observer is considered to compensate the estimated torque value into the current loop in order to respond to the system load changes faster, thus enhancing the system anti-interference capability. The experimental results show that the sliding film observer can be used as an effective alternative to the speed and position sensors, and the sensorless control is realized.