A Sensorless Control Strategy Exploiting Error Compensation for Permanent Magnet Synchronous Motor Based on High-Frequency Signal Injection

A permanent magnet synchronous motor (PMSM) is typically run at low speed with a sensorless control system using a high-frequency signal injection method. However, current harmonic and gain errors compromise rotor position observation accuracy. In this paper, we analyze the reasons for rotor observation angle error and propose a new rotor position observer with error compensation. This new sensorless control tool obtains the compensation error angle by extracting the negative high-frequency current in order to estimate the rotor position information accurately. The experimental results show that the error compensation strategy proposed in this paper can improve the accuracy of rotor position observation and achieve operation of the PMSM in both steady-state working conditions and dynamic working conditions at low speed.