Optimized High-Order Compensation Topology for PT-WPT Systems With Expanded Constant Power Region

The wireless power transfer (WPT) system based on the parity-time (PT) symmetric principle has been verified to have the outstanding benefits of constant efficiency and output power against the coupling coefficient in the exact PT-symmetric region. However, the confined constant power (CP) region needs to be expanded to meet the demands of different applications. To address the problem, the primary-series (S) and secondary-series-inductor-series-parallel-capacitor (SLSPC) high-order compensation topology of the PT-WPT system is proposed and optimized in this article. First, the model of the proposed system is built based on the coupled-mode theory, and the output performances are compared with the series–series (S–S) topology and other high-order topologies. It is found that the proposed S-SLSPC PT-WPT system can obtain a larger CP region by the reduction of the critical coupling coefficient. Besides, the CP region can be regulated by adjusting the parameters of resonance capacitors in different practical application scenarios. Finally, the experimental prototype of the proposed S-SLSPC PT-WPT system is developed to verify its output characteristics.