Predictive Current Trajectory Control for PMSM at Voltage Limit

Abstract

This paper presents a fast predictive current trajectory strategy for permanent magnet synchronous motors (PMSMs) at voltage limit. The current hexagon obtained from the voltage hexagon of the inverter represents the region that the currents can reach in the next switching periond. The nearest avaliable current point to the reference is solved by geometrical method on the current plane. The output of the proposed algorithm is divided into four cases according to the position of the current points. The algorithm combines FCS-MPC and DPCC, has the merits of both method and also the fast dynamic at voltage limits. In order to increase the robustness against the parameter variations, moving horizon estimator is utilized. The rotor flux is eliminated in the algorithm and the voltage errors caused by resistance and inductance mismatches are compensated by the estimator. Several experiments are performed with DPCC, FCS-MPC and the predictive current trajectory control method. These comparisons validate the effectiveness of the proposed method.