A New Isolated Series-Resonant AC–DC Converter for EV

This article proposes an isolated series resonant (ISR) AC–DC converter with reduced voltage stress. The proposed topology employs a split-capacitor half-bridge (SC-HB) configuration with bidirectional AC-side switches and incorporates a semi-active rectifier (SAR) on the DC side to eliminate secondary-side circulating current and prevent reverse power flow. This effectively controls the power conversion through phase-shift control. The proposed converter eliminates transformer saturation and achieves zero-voltage-switching (ZVS) turn-on for all switches. The reduced voltage stress allows, using low-voltage devices with lower drain-to-source on-state resistance and output capacitance. The optimized operation, keeps conduction losses comparable while significantly reducing switching losses. As a result, total losses are reduced. This enables operation at higher switching frequencies while maintaining high efficiency. A self-regulated mechanism is introduced to suppress transformer saturation in the ISR AC–DC converter. A 1-kW experimental prototype is developed, achieving full ZVS over the entire line cycle with unity power factor (UPF) and high efficiency across a wide range of input voltage and load conditions; the results closely match the theoretical analysis, and validating the working of the converter.