Torque Ripple Reduction Analysis and Dynamic Performance Improvement of PMSM Drives Based on Direct Torque Control Strategy

Abstract

This paper examines the torque ripple reduction based on direct torque control (DTC) for permanent magnet synchronous motors (PMSM). The proposed DTC method includes reference flux vector calculator and torque estimator introducing space vector pulse-width modulation (SVPWM) method. Since the constant switching frequency is produced by SVM technique, the SVPWM method enables the drive to produce voltage vector of any direction and magnitude thus, torque ripple is eliminated compared with classical hysteresis DTC. A digital signal processor (DSP) is used for PMSM drive system. The effectiveness of the proposed method is verified by both simulation and experimental results. Experimental results obtained by a motor & generator setup are shown to verify the operating performance. The experimental setup exhibits validity of the analysis and demonstrates good dynamic response by reducing torque ripples.