A Design and Analysis Method for Multimodal Coils Based on Maxwell 3D

A methodology for the systematic investigation of the electromagnetic performance of various types of coupling coils is proposed. This methodology is based on a multimode coil design and analysis method that utilizes Maxwell 3D. Initially, the fundamental theory of electromagnetic coupling coefficients is expounded, and the structural characteristics of single-turn, Litz, and square wires, along with their application scenarios in wireless power transfer (WPT), are examined. Subsequently, a multimodal coupled coil model is constructed to model and simulate the study of coils with different geometries (PCB and circular) and wire types (single-turn and Litz wire). Through the simulation of magnetic field distribution, mutual inductance, and coupling coefficients, the study reveals the effect of geometry and wire type on coil performance. The simulation results of magnetic field distribution demonstrate that geometry significantly impacts magnetic field strength and its uniformity. Furthermore, mutual inductance simulation results demonstrate that the Litz coil exhibits a high coupling efficiency in short-distance transmission, though its advantage gradually diminishes with an increase in transmission distance. Furthermore, the coupling coefficient simulation indicates that the circular coil exhibits superior performance in comparison to the square coil, underscoring the significance of geometry in influencing coupling efficiency. The findings underscore the efficacy of the Maxwell 3D simulation method in evaluating the performance of multimode coils and establish a theoretical foundation for the design and optimization of wireless power transmission coils.