Summarization of Sensorless Positioning and Speed Measurement for Permanent Magnet Synchronous Motor

The precise and efficient control of permanent magnet synchronous motor (PMSM) relies on real-time and accurate position and speed information. The traditional motor position detection needs to be realized by position sensor. However, for PMSM used in maglev transportation, the sensor scheme is complex and high cost. Therefore, the paper takes position and speed sensorless detection of PMSM as the research goal, and systematically summarizes the principles, applicable environment and improved methods from zero-low speed and medium-high speed, which provides reference for sensorless control of PMSM for rail transit.