Modeling and Design Considerations in the Control of an Isolated Bidirectional Electric Vehicle Charger

Abstract

With the advent of new electric vehicle technologies, research into electric vehicle chargers have also progressed immensely in the recent times. This paper discusses the modeling and design considerations involved in a bidirectional isolated electric vehicle charger. An electric vehicle charger comprises of a front end rectifier with power factor correction capability, with or without bidirectional feature cascaded with an isolated or non isolated DC-DC converter. The small signal impedance models of these converters are developed which aids in analysing the interaction between the two converters, while they try to meet their own control objectives. It is imperative to ensure that these interactions will not induce unintended oscillations at the DC link or instability in the cascaded system. Detailed simulation results of this cascaded system are presented to validate the analysis.