Efficient Assessment of the Impact of Metallic Obstacles on the Wireless Power Transfer in Loosely Coupled Links

This paper presents a novel extension of a well-known analytical model for loosely coupled wireless power transfer (WPT) systems in metallic environments. For the first time, coil misalignments and the impact of metallic obstacles are both modeled analytically, thus enabling the efficient assessment of the power transfer efficiency (PTE). The impact of an obstacle is extracted from an initial electromagnetic (EM) simulation. This is accomplished by comparing the resulting PTEs with and without the presence of the obstacle. The impact is considered in the analytical model for the computation of the PTE for arbitrary coil misalignments in the proximity of the obstacle. We found the influence of the obstacle to be independent of coil misalignments, thus its impact on the PTE can be accounted for by a mathematically simple multiplication by a constant. Therefore, the derived analytical model is a major step towards efficient WPT system design in metallic environments.