Bridgeless Buck-Boost Converter for Power Factor Correction in an Isolated Cuk Converter Driven EV Charger

On board chargers had given a phase lift to popularise Electric vehicles (EVs) and active research is on the fray to develop still efficient, compact, and reliable on board chargers. An earnest attempt in this regard to develop a two-stage onboard charger, consisting of a bridgeless buck-boost PFC converter in the primary stage and an isolated Cuk converter at the secondary stage is described in this paper. The PFC stage maintains a DC bus voltage of 400 V while achieving natural power factor correction by operating in dis-continuous conduction mode (DCM), reducing control complexity and enhancing reliability. Unlike in many other topologies where both current and voltage control is employed, the second, isolated Cuk converter stage, effectively charges the battery by a simple voltage control. Thus, the proposed charger employing bridgeless topology, minimizes the switching losses and uses a fewer components. The overall system performance under the proposed charger is verified by simulation, wherein the total harmonic distortion (THD) regulations are confirmed, power factor is improved, and charges batteries efficiently, making it a viable and effective solution for applications employing electric vehicles.