Research on Sliding Mode Observer of Permanent Magnet Synchronous Motor Based on PI Controller

This paper investigates the design and application of a sliding mode observer (SMO) in the control strategy of a Permanent Magnet Synchronous Motor (PMSM) without a position sensor. PMSM is widely used in industrial and transportation sectors due to its high efficiency and performance. However, accurate state estimation has always been a challenge due to its nonlinearity and parameter uncertainties. To address this issue, this paper proposes a state estimation method based on a sliding mode observer. The sliding mode observer achieves state estimation by introducing a sliding surface that can resist the influence of external disturbances and parameter variations, thereby exhibiting strong robustness. Based on the voltage equation of the PMSM, an improved sliding mode observer is designed to estimate the rotor position and velocity of the PMSM. The improved sliding mode Research on sliding mode observer of permanent magnet synchronous motor based on PI regulatorobserver effectively mitigates the chattering problem of the sliding mode observer by improving the switching function, enabling estimation of the back electromotive force without the use of filters, and significantly enhancing the accuracy of rotor velocity and position estimation.