Series Series Compensation Topology for Load Independent Current and Voltage Output in Wireless Power Transfer System

This article addresses the need for an efficient and compact wireless power transfer (WPT) system for Unmanned Aerial Vehicles (UAVs), focusing on constant current-constant voltage (CC-CV) output for secure Li-ion battery charging. The work proposes a straightforward WPT with a series-series compensation topology to achieve the desired CC-CV output, highlighting load variations, soft switching, and efficiency. The simulations indicate that circular coils in the system offer higher coupling coefficients. Furthermore, inverter switches are designed for both zero voltage switching (ZVS) and zero current switching (ZCS) at the respective turn-ON and turn-OFF conditions in CC charging, while only ZVS at turn-ON condition in CV charging, ensuring high efficiency. A 69 W prototype, with coupling coefficient (k = 0.2), operating frquency at 77.3 kHz in CC mode and 86.5 kHz in CV mode, validates the proposed system.