A Dual-Frequency Modular Wireless Power Transfer System for Auxiliary Power Supply of Power Electronics Converters

In some industrial application scenarios, multiple constant-voltage (CV) outputs with galvanic isolation are required. Selective power transfer among the CV outputs can enable its flexibility. This paper proposes a modular singlechannel wireless power transfer system for industrial power supply with a dual-frequency hybrid compensation topology. The series-series topology is adopted for CV outputs at the two CV output frequency points. The band-stop filter with a parallel resonant network is designed to filter the undesired frequency component and the series series-parallel resonant network is formed to avoid the impact of the band-stop filter on the desired frequency component. In this way, selective power transfer with CV outputs can be achieved by changing the working frequency. The mathematical model of the proposed compensation topology is established and analyzed. The transmission coils and the compensating inductors are integrated to achieve a compact structure. The design principles of the coupler parameters are proposed and a design example is given. An experimental prototype is built to verify the theoretical analysis. The system realizes CV outputs and supplies power to different loads at different working frequencies, with an average transfer efficiency of 85.23% and a maximum output power of 85.95 W