Sensorless Control Strategy for Permanent Magnet Synchronous Motor Integral Adaptive Observer

Abstract

A position sensorless control strategy with improved integral fuzzy sliding mode observer and rotor position error compensation is proposed to address the low rotor-position observation accuracy of the traditional sliding mode observer for permanent magnet synchronous motors. First, an integral adaptive sliding mode current observer is developed to weaken the chattering effect caused by the switching function of the sliding mode observer, and the speed and position fluctuations are suppressed by introducing a finite integral sliding mode function and an equivalent switching control law, and a fuzzy adaptive rule is designed to adjust the back electromotive force observation gain in real time. Second, a closed-loop phase tracker is designed to correct the rotor position to compensate the position offset caused by the phase-locked loop and low-pass filter, enabling us obtain accurate rotor position. Finally, the effectiveness of the proposed method is verified by simulation and experiment. The results reveal that the proposed method can accurately observe the rotor speed and position information of the motor under different operating conditions with fast convergence and strong robustness.