Adaptive Finite Time Disturbance Observer-Based SPMSMs Position Sensorless Drive

In this article, an adaptive finite time disturbance observer (FTDO)-based position sensorless drive method is proposed to improve the position and speed observation performance of surface-mounted permanent magnet synchronous motor (SPMSM). Firstly, to observe system disturbance in a finite time, an adaptive FTDO is proposed by designing an adaptive law and combining it with a fixed time sliding surface. Due to the designed adaptive law can stably track the bound of the first-order derivative of disturbance, the adaptive FTDO does not need to know the bounds of disturbance and its first-order derivative, which will also suppress the chattering of observed disturbance. Subsequently, to compensate for the disturbance in the observed flux initially obtained by the flux observer and simultaneously observe the speed, an adaptive speed observer is designed by adopting the proposed adaptive FTDO. Besides, the finite time convergence and stability of the adaptive FTDO have been demonstrated according to the Lyapunov theory. The coefficient setting guides for adaptive FTDO are also provided. The effectiveness of the proposed adaptive FTDO-based method is verified by contrastive experiments on an SPMSM.