Research on speed sensorless method for permanent magnet linear synchronous motor based on high frequency pulsating voltage signal injection

The position and speed detection of maglev train is critical to train control system. The common methods of speed measurement include speed sensor measurement and speed sensorless measurement. The use of sensorless method can significantly reduce costs and it's not influenced by various environmental factors. In this paper, a high frequency pulsating voltage injection method is proposed for the PMLSM, which is used to calculate the speed and position information of the motor. This method is suitable for low speed measurement and it can be used for the permanent magnet linear synchronous motor (PMLSM) with non-salient pole machine. The effectiveness of the method is verified by experiment results.