The Non-Singular Fast Terminal Sliding Mode Control of Interior Permanent Magnet Synchronous Motor Based on Deep Flux Weakening Switching Point Tracking

Abstract

This paper presents a novel non-singular fast terminal sliding mode control (NFTSMC) based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor (IPMSM) drive systems. The mathematical model of flux weakening (FW) control is established, and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve. Next, a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time. Then, an extended sliding mode disturbance observer (ESMDO) is designed to estimate the uncertainty of the system. Finally, compared with both the PI control and sliding mode control (SMC) by simulations and experiments with different working conditions, the method proposed has the merits of accelerating convergence, improving steady-state accuracy, and minimizing the current and torque pulsation.