Research on Sensorless Control of PMSM Based on a Novel Sliding Mode Observer

Abstract

For the sensorless control of permanent magnet synchronous motor (PMSM) drive system, it is necessary to realize the motor speed and position estimation. In order to overcome the serious chattering problem caused by the discontinuous control, on the basis of analyzing the principle of the traditional sliding mode observer, the Sigmoid function is introduced to the traditional sliding mode observer, and a new type of sliding mode observer is designed and its stability is proved. The simulation test results show that the novel sliding mode observer based on Sigmoid function eliminates the serious problem of chattering existing in traditional sliding mode observer, reduce the filter links and phase compensation link, and it can realize the precise estimation of the speed and position of the PMSM. At the same time the proposed method is effective for sensorless control of permanent magnet synchronous motor.