Enhanced Sensorless Control Accuracy for PMSM Using Finite-Time Adaptive Observer and Parallel PLL

This brief proposes a sensorless control scheme for the permanent magnet synchronous motor (PMSM), which is based on a finite-time adaptive state observer (FTASO) combined with a parallel phase-locked loop (PPLL). In this scheme, an adaptive gain mechanism, a nonlinear compensation term, and the characteristics of the finite-time state observer are integrated to enhance the estimation accuracy and achieve finite-time convergence of the back electromotive force (EMF). Based on the EMF estimated in the initial phase, a parallel PLL is designed to effectively reduce the angle error induced by speed variations during acceleration and deceleration. Finally, the effectiveness of the proposed sensorless control scheme is validated through simulation comparison with the conventional algorithms.