A Switched Capacitor-Based Single Switch Circuit with Load-Independent Output for Wireless Power Transfer

Abstract

Double-sided Inductor–Capacitor–Capacitor (LCC) or hybrid compensation network is often used in the traditional methods to realize load-independent output in wireless power transfer; however, these methods require the changes of operating frequency or compensation network, and the adoption of more switches and components, resulting in the reduction in the reliability of the system. In this article, a single switch topology using a switched capacitor was proposed, which can realize load-independent output characteristics by only switching the branch once, characterized by the strength of fewer components, simple control, and high reliability. The analysis of this topology and the accurate parameter design method were given, and the sensitivity analysis was also carried out. Finally, a 180 W wireless charging prototype with 60 V/3 A was built using the proposed topology, which confirmed the accuracy of model analysis and the practical feasibility of the proposed strategies.