Self-Excited Compensatory Transmitters with Phase-Shifted Sinusoidal Control for Wireless Charging Fields

This study uses a buck power factor correction (PFC), a current-fed push-pull resonant converter and phase-shift sinusoidal control to construct a self-excited compensatory transmitter for a low-voltage wireless charging system. The circuit uses a current signal on the wireless power transfer (WPT) and the start-up sinusoidal signal for compensation to allow the power switch's driving signal (vgs1 and vgs2) to be finely adjusted to the primary side current so the circuit to operate near the resonant frequency and the power switches approach zero-voltage switching (ZVS). The experimental results show that both driving signals follow the voltage changes across the resonant capacitor and the output power approaches 54 W.