Modeling and Control of a Three-Phase Interleaved Buck Converter as a Battery Charger

Abstract

In this paper, a control design methodology is proposed for the implementation of a three-phase interleaved buck converter as a battery charger. The control strategy consists of a multiple-loop controller in cascade configuration to implement the constant-current constant-voltage (CC-CV) protocol for the fast charging of an electric vehicle (EV) battery. To compensate for the inherent asymmetric distribution of the current between the phases, the first control loop (inner loop) is dedicated to implement the democratic current sharing technique, while the two outer loops constitute a seamless controller, which allows a soft transition from CC mode to CV mode when charging the battery. The controllers are designed using the root locus method and conventional rules for cascade controllers. The design methodology is validated and tested by numerical simulations of the switched model system implemented in PSIM