Adaptive robust nonlinear feedback control of chaos in PMSM system with modeling uncertainty

It has been proved that chaos exists in the permanent-magnet synchronous motor (PMSM) system when its parameters satisfy some condition, and it would degrade the efficiency of the PMSM system dramatically. In this paper, an adaptive robust control method is proposed to eliminate or suppress the chaos in PMSM, based on the mathematical analysis of chaotic property of the PMSM system. It not only accounts for the parametric uncertainties (structured uncertainties) but also takes the external load torque disturbances (unstructured uncertainties) into account. Adaptive control item is designed to deal with the former while robust item is designed to deal with the latter and the parametric estimation error respectively and both of them are integrated together via a feedforward cancellation technique. Numerical simulation results show that this method is more reliable, more accurate, and thus more applicable, compared to the existing control methods.