Improved Sensorless Control of PMSM Based on Super Twisting Algorithm-Sliding Mode Observer

This paper addresses the challenge of reduced precision in the observation of rotor information in permanent magnet synchronous motors (PMSMs) due to the chattering and delay issues inherent in conventional sliding mode observers. An advanced sensorless control method for PMSMs is proposed, leveraging an enhanced superhelical sliding mode observer. First, the improved observer is constructed by replacing the sign function in the standard superhelical sliding mode algorithm with a novel saturation function, thereby significantly reducing sliding mode chattering. Second, a phase-locked loop (PLL) structure is utilized to substitute the sign function in the traditional sliding mode observer, allowing for more accurate extraction of the PMSM’s position and speed information and effectively resolving the lag issue. Finally, a sensorless control system for PMSMs is developed, and its performance is validated through simulations conducted in MATLAB/Simulink. The comparison with the traditional sliding mode observer’s findings underscores the enhanced capabilities of the suggested approach.