Comparative Analysis of Single-Phase Shift and Extended Phase Shift Modulations in Dual Active Bridge Converters for Fast EV Charging

This paper presents a comprehensive comparison between Single-Phase Shift Modulation (SPSM) and Extended Phase Shift Modulation (EPSM) in Dual Active Bridge (DAB) converters, focusing on their switching losses, performance, and efficiency under various load conditions. The analysis is conducted using SPICE-based simulations to evaluate the converters' behaviour under low, medium, and high-loading conditions. The DAB converter is designed for fast-charging electric vehicle (EV) applications with the design specifications of 5 kW, 800V/400V employing Silicon Carbide (SiC) MOSFETs with switching frequency of 100 kHz. The comprehensive comparative analysis of the two modulation strategies yields critical insights regarding their appropriateness for various applications and operational scenarios, which is fundamental to achieving efficient high-power DC-DC conversion in advanced electric vehicle fast charging systems. Key words. EV fast charging, DAB, Silicon carbide devices, Single Phase Shift, Extended Phase Shift.