Single-phase single-stage bidirectional isolated ZVS AC-DC converter with PFC

This paper presents a single-phase bidirectional isolated AC-DC converter with Power Factor Correction (PFC) consisting of a half-bridge on the AC side and a full-bridge on the DC side to accomplish single-stage power conversion. The converter applies a new control scheme combining phase-shift and frequency modulation to achieve Zero-Voltage-Switching (ZVS) over the full range of the AC line voltage. Compared to the conventional boost PFC approach, the proposed converter eliminates high frequency harmonic distortions on the mains due to the inherently integrated LC input filter stage. The operating principle in AC-to-DC and DC-to-AC under ZVS conditions by means of analytical considerations are provided. Simulation results and a detailed loss model of a 3.3 kW electric vehicle battery charger to connect to the 230 V_rms / 50 Hz mains considering a battery voltage range of 280 V to 430 V validate the theoretical analysis. The converter can also be used as a submodule in a Cascaded H-Bridge Converter (CHB) for medium or high voltage applications.