Design and Experimental Assessment of a 60 kW All-Si Three-Phase Six-Leg T-Type Rectifier for Electric Vehicle Ultra-Fast Charging

Abstract

This paper presents a complete design methodology for a 60 kW AC/DC active rectifier stage of a modular electric vehicle ultra-fast battery charger. Due to the well known performance of three-level unidirectional rectifiers, a T-type converter topology is selected. Moreover, in view of the high target nominal power of the converter, a six-leg approach is adopted, thus halving the current rating of each bridge-leg and allowing for the adoption of conventional discrete semiconductor devices (i.e., Si MOSFETs and Si diodes). Therefore, a step-by-step design procedure is proposed, based on the selection, sizing and/or optimization of all main converter active and passive components, including the semiconductor devices, the DC-side capacitors, the AC-side inductors and the loss dissipation system (i.e., heatsink and fans). Finally, a 60 kW converter prototype is realized and its performance is experimentally assessed.