Output Voltage Range of a Resonant Inductive WPT Link Operating in Load Independent Regime

This paper presents an analysis of series-series compensated inductive wireless power transfer system, operating at load-independent frequency without neglecting equivalent primary and secondary resistances. It is shown that the output DC voltage remains load dependent, residing in a well-defined range. Moreover, while valid for the majority of load range, phasor-domain equivalent circuit fails to predict the output DC voltage under light load conditions. Therefore, solution based on time-domain analysis is proposed to predict the output DC voltage under no-load conditions. The proposed methodology is well-verified by simulation results of a 400V, 3.3kW inductive wireless power transfer link.