A novel fuzzy flux sliding-mode observer for the sensorless speed and position tracking of PMSMs

This paper proposes a novel fuzzy flux sliding-mode observer (FFSMO) with a phase-locked loop (PLL) for the sensorless speed and position tracking of permanent-magnet synchronous motors (PMSMs). The purpose of the novel FFSMO is to accurately estimate the position and velocity of the rotor. Compared with the conventional sliding-mode observer (SMO), the novel FFSMO can not only eliminate the low-pass filter (LPF) and phase compensation module but also improve the estimation accuracy. To adjust the SMO gain ε and to reduce the chattering of the sliding-mode variable structure, a fuzzy logic controller (FLC) is proposed and integrated into the observer. Moreover, a PLL method is employed to obtain accurate position and velocity estimates and reduce the adverse influence of noise. The stability of the proposed FFSMO is verified using Lyapunov's second method. An experimental platform is built, and the experimental results show the effectiveness of the FFSMO.