Calculation of Mutual Inductance based on 3D Field and Circuit Coupling Analysis for WPT System

Determination of mutual inductance in the WPT system based on the electromagnetic coupling mode is crucial for system design and efficiency optimization. The analytic formulas and experimental methods which only aim at a coupling coil with a certain type of configuration and parameters are not universal approaches. Therefore they can’t serve as a design basis for the system optimization. This paper presents a novel method based on 3D field and circuit coupling analysis to calculate mutual inductance of coupling coils with arbitrary spatial distribution for WPT system. The method can obtain maximum efficiency under the condition that the spatial distribution of coupling coils are irregular and restrained in actual physical systems. The method has made a breakthrough and provided a powerful tool for the design and optimization of electromagnetic coupling power transmission system.