Analyzing an Equivalent Circuit to Model Wireless Energy Transfer Coils by Inductive Link with Massive Wires

Abstract

The increase of the researches on Wireless Power Transmitter (WPT) brings the necessity of having a good model of the system to facilitate its design analysis. WPTs are usually composed of a transmitter coreless coil that carries power at hundreds of kHz and transmits it to a receiver coreless coil with no physical contact. Most models are based on the regular transformer equivalent circuit without the parallel resistance, which models the core losses. However, when the coils are made with massive wires, there are extra losses that must be considered. This paper investigate the effect of frequency and the coupling between massive wire coils on the parameters of the equivalent electric circuits, and the coil proximity and skin effects. Finally, it proposes a generic equivalent frequency dependent electric circuit to model the coils.