Position Sensorless Drive of High Speed Permanent Magnet Synchronous Motor

In this paper, a discrete-time sliding-mode back-EMF estimation method for high speed permanent magnet synchronous motor (HSPMSM) is proposed. Firstly, the discrete-time model of the HSPMSM is developed. Then a discrete-time sliding-mode back-EMF observer in the γδ coordinate is proposed. The reaching law of the sliding-mode observer is designed with the free-order sliding mode switching scheme. The stability and the dynamic response of the proposed sliding-mode observer are guaranteed. The analysis of the robustness and estimation error of the proposed observer are also provided in this paper. Additionally, considering the startup of the HSPMSM, the proposed starting method is effective at both zero speed and nonzero speed. Finally, the effectiveness of the proposed method is validated by both simulation and experimental results on a 100 kr/min motor with 10 kHz sampling frequency.