Robust Optimal Sliding Mode Tracking Control for PMSM with Uncertainties

摘要

This paper presents a design method of a robust linear quadratic regulator (LQR) for tracking control ofpermanent magnet synchronous motors (PMSMs), which are modeled by nonlinear dynamics with mismatched uncertainties. The input-output linearization technique is firstly adopted to transform the PMSM model into an equivalent linear one, and a LQR is designed based on the transformed system by ignoring uncertainties. However, the optimal control for the nominal system is very sensitive to uncertainties, so the sliding mode control strategy is used to robustify the LQR. An optimal integral sliding mode surface is constructed, by which the initial condition is on the surface and reaching phase is eliminated. And a sliding mode control law is synthesized to reject uncertainties. Thus, the system exhibits global robustness to the uncertainties and the ideal sliding mode dynamics is the same as that of optimal LQR for the nominal system. A global robust optimal sliding mode control (GROSMC) is realized. Finally, numerical simulations show that the good tracking performance of the PMSMs can be achieved and the uncertainties can be compensated using the proposed controller.