Sensorless Fixed-Time Sliding Mode Control of PMSM Based on Barrier Function Adaptive Super-Twisting Observer

For the purpose of simplifying the physical structure, improving the anti-disturbance performance and enhancing the response performance of permanent magnet synchronous motor (PMSM), this article proposes a novel sensorless fixed-time sliding mode control scheme with fast fixed-time convergence for PMSM. First, to realize sensorless control, a barrier function (BF)-based adaptive super-twisting observer (BF-ASTO) is designed to accurately estimate the rotor's position and speed of the PMSM. The BF is chosen as an adaptive algorithm for online tuning the parameters of BF-ASTO to achieve a better speed estimation performance. Then, an adaptive fixed-time integral sliding mode controller (AFTISMC) is proposed based on fixed-time stability theory, which guarantees both the independence of the settling time on the initial conditions and the finite time speed tracking error convergence. Lyapunov stability analysis is rigorously given for both the designed BF-ASTO and the AFTISMC, respectively. Finally, real-time experimental results are provided to verify the effectiveness of the proposed control method with the BF-ASTO.