Dynamic Modeling and Control of a Three-Port ZVS-PWM Three-Phase Push Pull DC-DC Converter

Abstract

This paper proposes the mathematic model and the control of the current and voltage loops of the ZVS-PWM three-phase current-fed push-pull DC-DC converter. The converter has three ports, two bidirectional ports and one unidirectional port and can be used in various applications such as electric vehicles, battery charging system, fuel cell, isolated mini grids and micro grids. The proposed control is able to invert power flow by imposing main inductor current value and direction as well as maintaining voltage at a given port under load variations. The control structure for each case is presented, as well as the deduction of the main mathematical expressions. In order to validate the performance of the proposed control strategy, simulation results for a 500 W converter with 50V in port 1 and 200 V in port 3 and a switching frequency of 40 kHz are presented here.