Study of performance improvement of slotless SPMSM position sensorless control in very low-speed region

This paper proposes a method for improving the performance of a position sensorless control system for a slotless surface permanent magnet synchronous motor (SPMSM) in a very low-speed region. In position sensorless control based on a motor model, accurate motor parameters are required because parameter errors would affect position estimation accuracy. Therefore, online parameter identification is used. The error between the reference voltage and the voltage applied to the motor is compensated to ensure accuracy and stability of the sensorless control system. In this study, two voltage error compensation methods are used: compensation method 1, which is the conventional method and compensation method 2, which is the proposed method. In the proposed method, online parameter identification and compensation method 2 are used. The proposed method is evaluated by experimental results.