Optimized Hybrid TPS and EPS Control for Tandem-Half-Bridge WPT Converter to Achieve Wide Load Range ZVS With Low Switching Loss

To achieve wide-range power regulation without using additional dc–dc, phase-shift full-bridge (PSFB) for wireless power transfer (WPT) system is a promising way. However, for the PSFB WPT system, switching loss is a key factor affecting the system efficiency. Single-side PSFB can regulate the power, but hard switching results in low efficiency and EMI problems. Dual-side PSFB can realize ZVS throughout a wide power range, but at the cost of high conduction loss and turn-off loss at light load. In this article, a WPT converter combining tandem half bridge (THB) and active rectifier (AR) is proposed to reduce the switching loss of the system at light and medium loads. Meanwhile, an optimized hybrid triple-phase-shift (TPS) and extended-phase-shift (EPS) control strategy is proposed to achieve ZVS and power regulation with adaptive modes, thus further reducing conduction loss and switching loss and optimizing light-load efficiency. Finally, A 1.2 kW experimental prototype was built, and the experimental results indicate strong agreement with theoretical analysis. All switches realize ZVS within the entire power range and maintain high efficiency ≥94.1%) in the power range of 16.7%–100%.