Novel Direct-Power-Control Strategy of Current-Source PWM Rectifier

This paper describes a novel control strategy of a current-source PWM rectifier, which is based on relay control of instantaneous active and reactive power, and presents its experimentally examined operation characteristics, followed by a theoretical derivation of the control algorithm. The most important feature of this strategy is a direct selection of switching modes of the PWM rectifier to restrict errors between the feedback values and the command values of the active and reactive power. Therefore, a theoretical analysis on relationship between the instantaneous power and the switching modes of the PWM rectifier is deeply investigated, which is essential to compose a switching mode table in the controller. Feasibility of the proposed strategy is experimentally verified, using a prototype setup. As a result, 92.7-% maximum efficiency and 99.9-% maximum total power factor are confirmed through the experimental tests.