Optimal Design of a Hybrid Wireless Power Transfer System with High Voltage Gain and High Efficiency

This paper presents a novel hybrid wireless power transfer (HWPT) system that achieves both high voltage gain and high efficiency through an integrated dual-mode power transfer mechanism. The proposed system employs a compact hybrid coupler composed of two pairs of decoupled bipolar coils at the center and two pairs of decoupled transmitter–receiver capacitive plates surrounding the coils. This unique configuration establishes two independent electric-field power transfer channels and two independent magnetic-field channels, effectively suppressing cross-coupling between adjacent channels and enabling simultaneous multi-channel power transmission. To regulate power distribution between the inductive and capacitive paths, an S-SP compensation network is adopted, featuring asymmetrical external capacitors on the primary and secondary sides. This compensation strategy facilitates constant voltage output while enhancing voltage gain and overall system efficiency. Comprehensive theoretical analysis is conducted to investigate the influence of coupler geometry and compensation parameters on system gain. A two-channel experimental prototype is developed to validate the proposed system architecture. Experimental results demonstrate a 140% gain range extension, with a maximum DC-DC efficiency of 86%.