A Multi-Domain Model for Variable Gap Iron-Cored Wireless Power Transmission System

Wireless Power Transfer (WPT) devices represent one of the most efficient and increasingly used technologies for the transfer of data and power in the near field range. The work analyzes and describes a new type of device: ferrite-cored, variable gapped, high-frequency power and data transfer systems. The classic theoretical models existing in literature, for Near Field Communication (NFC) and WPT devices, foreseen a lumped parameters characterization based onto an equivalent circuit model (ECM) representation. The strict interdependence between the different physical domains have clearly increased the difficulty in predicting the behavior of the device, due to the unwanted con-tinuous and chaotic variation of parameters. The proposed paper aims to provide a general and reliable multi-physics model based onto the co-simulation of a Spice®-based ECM analysis and the ESRF Radia®-based 3D Finite Volume Methodology (3DFVM) devoting particular emphasis to the intrinsic sensitivity with respect to variables that cannot be directly controlled, such as the variation of the air gap between the coupled coils interfaces. Furthermore, the work outlines a detailed and effective experimental methodology for the estimation of static and dynamic electro-magnetic parameters and the validation of the numerical models both under the time and the frequency domain, through the analysis of a real coupled WPT device.