Reduced-Order Model for Inductive Power Transfer Systems

As a DC-DC converter, an inductive power transfer (IPT) system requires a feedback control to stabilize the output. An accurate and simple small signal model is important for IPT systems to evaluate the control performance. In the past years, the extended describing function (EDF) is powerful to address the modeling issue for resonant converter. However, the high-order resonant tank of IPT would lead to a complicated model if EDF is directly applied. In order to simplify the model, this paper explores a circuit-based method to reduce the order for both series and parallel resonant circuits. An example LCC-C compensated system is used to explain the concept. This general simplification can be extended for any other high-order IPT systems.