A Multiobjective Optimization Modulation Strategy for Achieving Full-Range ZVS in GaN-Based Single-Stage Onboard Charger

In the pursuit of higher power density and operational efficiency in electric vehicle charging systems, the Boost-type integrated dual active bridge (BI-DAB) converter has garnered significant attention. However, traditional modulation schemes exhibit limited zero-voltage switching (ZVS) ranges and insufficient optimization flexibility, which diminishes efficiency and constrains the practical applications of BI-DAB converters. To address these challenges, this paper proposes a hybrid software-hardware multi-objective optimization modulation scheme designed to extend the ZVS operating range and enhance converter efficiency. A comprehensive ZVS model for the BI-DAB converter is established by which the ZVS conditions are derived. The influence of magnetizing inductance is considered, and a hybrid approach that combines the optimal design of magnetizing inductance and phase-shift optimization enables full-range all-ZVS operation. Additionally, the proposed modulation scheme facilitates seamless mode transitions while effectively achieving power factor correction (PFC) and quasi-optimal current stress conditions. Finally, a GaN-based 2 kW/150 kHz BI-DAB converter prototype was constructed, achieving a peak efficiency of 96.6% and a total harmonic distortion (THD) of 1.5%.