A Uni-Stage Isolated Charging System for Electric Vehicles Employing SEPIC and Buck-Boost Converter for Different Supply Voltage Semi -Cycles

In the current article, a uni-stage, isolated, non-bridged charging scheme is filed for the charging of LEVs (light electric vehicles) with enhanced power factor. A linear voltage to current relation is achieved on the supply terminal with the discussed scheme for EV charger so that the criteria of IEC-61000-3-2 are not violated. The charger consists of an AC-DC converter with two electrically isolated separate paths for both halves of the input terminal voltages. In the presented work, an isolated buck-boost and sepic converter-based non-bridged EV charger is introduced with the ability of power factor (PFP) preregulation at the supply end. The charger is reached by a combination of buck-boost and sepic converter which works as sepic and buck-boost converter-based chargers in the positive and negative half of input terminal voltages respectively. The nobility in this article is the elimination of back-feeding diodes. However, the same task is performed by antiparallel body diodes of the switches which results in reduction in components counting and increase in efficiency. The converter designed in the filed scheme is operated in discontinuous conduction mode (DCM) and the discussed electric vehicle charger topology is validated using the MATLAB simulation results.