Design and Control of Three Phase Single Stage Bi-Directional High Frequency Current Source Converter for EV Charging

Power electronics converters are required to provide reliable and efficient charging methods for electric vehicles (EVs). For a conventional charger, AC is rectified using boost derived rectifier and then stepped down to battery voltage level i.e. 400V using buck chopper. This paper presents a three phase buck PFC which will act as Rectifier i.e. Grid-to-Vehicle (G2V) as well as Inverter i.e. Grid-to-Vehicle (V2G) mode,in a single stage with unidirectional switches only. Using buck derived topology, three phase 400V AC is rectified and stepped down to 400V DC in single stage. An modified Space Vector Pulse Width Modulation (SVPWM) scheme is implemented for both G2V and V2G mode which reduces the switching loss while maintaining high quality of grid current. All analytical results are validated by simulation results using PowerSIM.

I. Introduction

The buck-type PFC is best suitable for charging EV where 400V dc is a good approach for the voltage level of the connection among the battery, motor, and charger[1]. Control of the CSI is simpler, it can buffer the output from grid voltage fluctuations, generates a predetermined magnitude of current to the grid and can thus achieve a high power factor[2]. Its output current is less dictated by the grid voltage. Moreover, it has inherent short circuit protection. Recently, the third-generation semiconductor devices such as the GaN and the SiC have been developing rapidly. They have fast switching speed, ultralow on-state resistance and high breakdown voltage, high temperature tolerance and high thermal conductivity, thus they are suitable for electrical vehicle (EV) [3]