Implementation of a PMSM Sensorless Control Method based on PLL back EMF

The underwater shaftless propulsion motor is not convenient to install position sensor. In this paper, a rotor angle detection technology based on PLL estimator is proposed. Firstly, the sensorless control principle of PMSM is introduced, and the control strategies of PMSM at zero speed, low speed and high speed are expounded respectively. Then, the code level simulation of PLL estimator based on C-MEX S-function is carried out, especially for the angle and speed estimation accuracy when the motor parameters change. Finally, the simulation code is transplanted to the motor experimental platform for verification. The results show that the algorithm has good adaptability and strong robustness, and has high angle observation accuracy in the range of medium and high speed.