Iterative Design of Class-D Inductive Power Transfer Systems Using an Equivalent DC Circuit

This work presents an equivalent DC circuit for modeling the steady-state behavior of a class-D inductive power transfer (IPT) system with series-parallel compensation capacitors. The equivalent circuit models lossy full-bridge (FB) and half-bridge (HB) class-D inverters and rectifiers. Convenient expressions for the maximum obtainable efficiency and component voltage and current stresses are derived using the model. We apply the model to a representative design problem, and formulate a step-by-step design procedure, with the goal of simplifying and generalizing the design process. The accuracy of the model is validated by comparing analytical results with simulated and measured results. The model's value for solving other types of design problems is discussed.