Robust current control-based sliding mode control with simple uncertainties estimation in permanent magnet synchronous motor drive systems

A simple and novel sliding mode control (SMC) method with uncertainties estimation is proposed for robust current control in a practical permanent magnet synchronous motor (PMSM). Based on the Lyapunov stability theorem, estimation laws are derived to estimate uncertainties of a PMSM caused by parametric variations and unmodelled dynamics. Then, the system robustness, as well as stability is guaranteed. Online estimated uncertainties can be used to eliminate the effect caused by the real uncertainties. Superior control performance can be obtained and the limitation in conventional SMC which is to know the upper bounds of the system uncertainties is unnecessary. Another advantage is that the proposed method can effectively suppress the current ripple for a PMSM. The proposed control method is very simple and can be effectively implemented. Based on a digital signal processor TMS320F2808, comparative experimental results demonstrate the effectiveness of the proposed control algorithm.