Torque Control Method for Permanent Magnet Synchronous Motor Operating in Field Weakening Region at Middle Speed Range

Abstract

In this paper, a torque control method for permanent magnet synchronous motors (PMSMs) functioning in the middle speed range of the field weakening control region is proposed. The current resonance due to d axis and q axis coupling cannot be neglected. The current resonance is depressed by the appropriate design of PID controller for the q-axis current. The proposed controller designing method is verified both numerically and experimentally. The influence of parameter changes is also examined to reveal that the L_q change affect the torque performance more than L_q and R_m does.