Magnetic Field Calculation for Three-Phase Wireless Power Transfer Systems

Abstract

In this paper, the magnetic field of a three-phase wireless power transfer (WPT) system is modelled analytically. Based on AMPÈRE'S law for straight currents, the contributions of individual coil elements are calculated and summed up. The result is a universally applicable expression for the total magnetic field depending on the geometric and electric parameters of the system. Further analysis reveals the existence of an optimal distance between primary and secondary side at which the magnetic flux density is maximized. This optimal distance is derived empirically, showing a linear dependency on only the spacings between the wire elements. The results in this paper expand the theoretical foundations and contribute to further optimization of three-phase wireless power transfer systems.