Research on Transfer Mechanism and Power Improvement Technology of the SCC-WPT System

Single capacitive coupled wireless power transfer (SCC-WPT) technology only needs one pair of metal plates for energy transmission. This provides a unique advantage in two-dimensional plane dynamic wireless power transfer. However, in practical application, this technology has a clear challenge in improving the transmission power ratings and efficiency. This article studies the power transfer mechanism of the SCC-WPT system based on stray capacitance and self-capacitance. A universal system model has been investigated, where the equivalent circuit model of the system is proposed. The two-port network of the coupler critical factors that limit the transmission power of the system has been analyzed. A new LC-CL compensation topology is proposed to achieve a phase difference of voltage between the primary side and secondary side to 90°, which improves the transmission power of the SCC-WPT system. In addition, the resonant operating condition of the system together with the efficiency is analyzed. Finally, an experimental prototype is built under the guidance of the analysis. Both simulation and experimental results verify the validity of the proposed model and the topology. The experimental results show that the prototype achieves 266 W output power with 62% dc-dc efficiency.