Distance Extension of S-PS Wireless Power Transfer System Based on Parity-Time Symmetry
Yuhu Qu, Bo Zhang, Wenchao Gu, Jianguo Li, Xujian Shu
Abstract
The application of wireless power transfer (WPT) has become more and more extensive, and the parity-time (PT) symmetric principle has been proved to significantly improve the degree of freedom of the WPT system without increasing the control complexity. However, the PT-symmetric region of the original WPT system with series-series (SS) compensation is limited. To overcome this drawback, a novel PT-symmetric WPT system with series-parallel-series (S-PS) compensation is proposed in this brief. The PS compensation network is converted to the S compensation network by equivalent circuit method. Then a mathematical model of the proposed system is established by circuit theory. It is found that the critical coupling coefficient of the proposed system are much smaller than the original PT-symmetric system. Furthermore, the proposed system has a compromise between transmission distance and transfer efficiency by setting the capacitance distribution ratio. A 26W prototype is built to verify the feasibility of the proposed method. Experimental results demonstrate that the proposed method doubles the transmission distance and improves the output power.