Analysis of Near-Field Magnetic Flux in the Three-Dimensional Wireless Power Transmitter

This paper presents the analysis of the near-field magnetic flux in a three-dimensional wireless power transmitter. The three-dimensional wireless power transmitter is constructed based on the concept of Helmholtz coil, which was originally invented for generating a constant static magnetic field. In recent years, this concept has been applied to wireless power transfer, enabling omnidirectional wireless charging. To facilitate the analysis and implementation of such three-dimensional wireless power transmitters, we conducted an analysis on their magnetic field distribution. In this study, we first present the theoretical calculation results. Additionally, we provide finite element simulation results and experimental data to verify the analysis. Moreover, we incorporate the magnetic flux modulation technique to the wireless power transmitter. By combining the evenly distributed magnetic flux and this modulation technique, a consistent magnetic flux linkage on the receiver coil is achieved.