Model-Predictive Direct Power Control With Vector Preselection Technique for Highly Efficient Active Rectifiers

Abstract

This paper proposes a novel method to reduce switching losses on the basis of a model-predictive direct power control (MPDPC) method for ac-dc active rectifiers. The main idea is to preselect voltage vectors to decrease switching losses at the next sampling period, and then select one optimum voltage vector among only the preselected voltage vectors to perform direct power control (DPC). The proposed vector preselection scheme enables a predefined cost function to consider only four vectors to control the real and the reactive power at every sampling period. The proposed MPDPC method using only the four preselected vectors stops switching operation of one leg exposed to the largest input current at every sampling period. On the basis of the preselected vectors at each sampling period, the proposed method can effectively reduce the switching losses, as well as accurately perform power control of the active rectifier.