Loss Characteristics and Optimization of a High-Power IGBT Phase-Shifted Full-Bridge ZVS Primary Inverter for Electric-Vehicle Wireless Charging

Buried wireless charging electric-vehicle inverter needs to achieve ZVS in face of adverse factors such as offset of primary inverter, variations of primary and mutual inductance, and variations in loading conditions. In this paper, analysis on the effects of a 10 kW IGBT phase-shifted full-bridge inverter with series-series resonant link on buried electric-vehicle wireless charging will be conducted. The loss model for the IGBT inverter, which integrates IGBT turn-off tail energy dissipation, partial ZVS operations, diode freewheeling, dead-time circulation and material losses of coil, ferrite and shielding materials, can be built based on publicly available datasheet and prototype specifications. Afterward, a segmented floating frequency phase-shift controller is employed to compensate for the drifting of resonant frequency and maintain ZVS operations with L_p-M mismatch. The performance of the proposed approach is evaluated through publicly available parameter simulation, benchmark analysis and controller logic CIL validation. The proposed approach increases the simulated ZVS coverage from 62% to 90%, cuts down the total rated losses by 17.0%, improves the peak efficiency to 94.7% and reduces the predicted maximum junction temperature by about 17°C.