Combined PWM and Phase-Shift Control of a Variable DC-Link PFC Integrated DAB Topology for Wide-Range High-Efficiency EV Chargers

This paper proposes a PFC-integrated Dual Active Bridge (DAB) EV charger topology for catering to a wide range of battery voltage and current variations from a single-phase AC mains. The control strategy optimally regulates the DC-link voltage, enabling synergistic pulse-width modulation and inter-bridge phase-shift adjustment. This ensures a nearly flat efficiency profile across varying input and output conditions. The converter supports grid-to-vehicle (G2V) charging, vehicle-to-grid (V2G), and vehicle-to-home (V2H) discharging with reactive power support, making it well-suited for onboard electric vehicle (EV) charging applications. A 2 kW prototype achieves a peak efficiency of 97.2% and sustains full load efficiency above 95% over a 150–450 V battery voltage range with 110 V and 220 V RMS grid inputs. Additionally, it maintains over 94% efficiency at light loads, with total harmonic distortion (THD) below 2.5%, demonstrating better performance over state-of-the-art single-stage solutions.