Misalignment Discussion of an Eight-Coil Wireless Power Transfer System

In this paper, an eight-coil wireless power transfer (WPT) system is proposed to improve the power transfer efficiency. This WPT system is designed with an array of multiple coils and resonators. Even in the case of misalignment, at least one coil pair maintains effective coupling, thus ensuring the operational efficiency of the system. The proposed eight-coil design yields a consistent magnetic field distribution, which strengthens the inter-coil coupling and enhances the system's robustness against misalignment. This paper analyzes the basic principles of the equivalent circuit diagrams of the WPT systems with two-, four- and eight-coils, and analyzes the corresponding calculation formulas such as coupling coefficient and transmission efficiency. The eight-coil WPT system's performance has been validated through simulation software CST, which can maintain high efficiency under a certain range of misalignment. Additionally, the proposed WPT system is benchmarked against other misaligned WPT systems to highlight its advantages.