Three-phase high power factor mains interface concepts for Electric Vehicle battery charging systems

This paper discusses novel three-phase high power factor mains interfaces appropriate for Electric Vehicle (EV) battery charging systems. Initially, a highly efficient two-stage ac-dc system, consisting of a three-phase line-commuted rectifier combined with a three-phase shunt connected Active Power Filter (APF) and a group of interleaved dc-dc buck converters operating in Triangular Current Mode (TCM), is presented. In order to replace the costly APF circuit of the front-end converter, while maintaining PFC capability at the input and allowing similar operating conditions for the back-end dc-dc converter, a rectifier topology employing an active third harmonic current injection circuit is proposed. In addition, a novel three-phase buck-type PFC rectifier is introduced for EV charging systems. The characteristics of the presented EV systems, including the principle of operation, modulation strategy, suitable control structures, and dimensioning equations, are described in detail. Finally, a comprehensive comparison of the studied converters rated to 12kW is shown.