General Pathways to Higher Order Compensation Circuits for IPT Converters via Sensitivity Analysis

This article first presents a systematic extension of second-order compensated inductive power transfer (IPT) converters, designed for achieving load-independent current (LIC) or load-independent voltage (LIV) output, to third-order compensated IPT converters through adding an inductor or capacitor at the input or output side. Conditions on the parameters to achieve the required output are given. Then, the system sensitivity to various parameter fluctuation is analyzed. Results from sensitivity analysis provide a convenient design guide for selecting parameters to achieve the required LIV and LIC operation for higher order IPT systems with fewer design constraints. Moreover, the analysis effectively reveals the roles of extra input-side or output-side inductors and capacitors in making the whole system less sensitive, and hence provides a fast understanding of the choice of higher order compensation circuits for applications addressing wide ranges of input variations, transformer coupling, and compensation network changes.