High-Performance DC–DC Converter Applied to the Receiving End of Current-Source WPT Systems

Wireless Power Transfer (WPT) systems often face performance limitations due to the right-half-plane zero (RHPz) in conventional constant-current-fed Buck converters, which can lead to negative undershoot and a slow dynamic response. In this paper, we propose a Buck converter topology with an additional active switch in series with the input capacitor. This mechanism-level modification effectively mitigates the RHPz. The operating modes, steady-state behavior, and small-signal characteristics of the converter are systematically analyzed. A tailored control strategy enables independent regulation of input and output capacitor charging times, supporting improved voltage regulation. Experimental results indicate that the proposed converter reduces settling time by approximately 83%, substantially suppresses negative undershoot, and maintains stable voltage regulation under reference step changes and load transients. The converter maintains high efficiency while demonstrating improved dynamic performance and stability relative to conventional topologies, providing a practical approach for advanced WPT applications.