Research on Control Strategy of Permanent Magnet Synchronous Motor Speed Sensorless System Based on New Wide Band Gap Devices

A new type of wide band gap semiconductor device, represented by silicon carbide, has advantages such as high switching frequency and low losses, which can significantly improve the power density of converter and system efficiency. Synchronous motors have the advantages of high efficiency, large moment of inertia, and fast dynamic response. In recent years, sensorless control technology for permanent magnet synchronous motor (PMSM) has become a research hotspot, which can significantly enhance system anti-interference, reduce costs, and reduce volume. This article is based on a 50 kw converter mainly consisted of new wide band gap semiconductor SiC devices, with a focus on the speed sensorless initial positioning method of PMSM to detect accurate initial position. Simultaneously, it aims to achieve the stable switching and control from low to medium and high speeds of PMSM without speed sensors. By comparing with the measured values of the code disk, system experiments are conduct in the full speed domain to verify the accuracy and reliability of speed sensorless control, which has good theoretical significance and application prospects.