A predictive loss minimisation direct torque control of permanent magnet synchronous motors

Abstract

Although permanent magnet synchronous motors (PMSMs) are inherently of high efficiency, their efficiency is enormously dependent on their control strategy. The purpose of this paper is to improve the efficiency of PMSMs under a direct torque control (DTC) method. The main idea behind the proposed method is to predict a required small change of the stator flux amplitude at each sampling period to reduce the machine electrical loss before the change is applied. Accordingly, at every sampling time, a voltage vector is predicted and applied to the machine to change the flux amplitude in a way that the electrical loss decreases. The results of simulation show significant improvement in the machine efficiency in addition to a very fast and smooth response under the proposed method.