Impacts of SPS, DPS, and EPS Modulations on the Reliability of Modular DAB EV Chargers

The modular dual-active-bridge converter plays a pivotal role in high-power electric vehicle charging systems due to its efficiency, bidirectional power transfer, and scalability. Among widely adopted modulation techniques, single-phase-shift, extended-phaseshift, and dual-phase-shift are commonly used, with the reduction of minimum backflow power being a key design objective. However, the impact of these techniques on the reliability of power-switching devices, influenced by thermal stress and mission profiles, remains unexplored. Thermal modeling and lifetime prediction methods are employed to assess the impact of different modulation techniques on the converter under a year-long mission profile. The results reveal that the single-phase-shift offers superior reliability performance, while other modulations negatively influence system-level reliability.