Continuous Nonsingular Fast Terminal Sliding Mode Control for Speed Tracking of PMSM Based on Finite Time Disturbance Observer

A continuous nonsingular fast terminal sliding mode (CNFTSM) control strategy with an automated double power reaching law is proposed to improve the performance of speed dynamic response and accuracy tracking for permanent magnet synchronous motor (PMSM) servo system. In pursuit robustness against system uncertainties, a finite-time convergent extended state observer (ESO) designed estimate external disturbances, parameter variation, unmodeled dynamics as feedforward compensation output feedback The developed controller, based on Lyapunov stability theory analysis, can guarantee finite time from any initial in presence internal disturbances. modified achieve enough convergence rate compared exponential law, inherent chattering reduced when states approach equilibrium point. Theoretical analysis simulation results demonstrate that composite controller higher than conventional method.