Minimizing Torque Ripple of Highly Saturated Salient Pole Synchronous Machines by Applying DB-DTFC

Abstract

Deadbeat-direct torque and flux control is a flux-observer-based high-bandwidth digital closed-loop torque control law that achieves the commanded torque at the end of each switching period. When flux estimation is accurate, instantaneous torque is fed back and undesirable pulsating torque is inherently minimized. This study presents real-time flux-observer-based torque ripple estimation of a highly nonlinear synchronous reluctance machine. Saturation and cross saturation are incorporated directly into the control law, and are considered in each switching period. Deadbeat torque response and torque ripple reduction is demonstrated experimentally. Finite element method simulations validate the torque ripple minimization.