Antithetical Design Methodologies of Position-Free Transmitter Coils in Wireless Power Transfer

This paper presents design concepts, design implementation and results evaluation of two antithetical design methodologies for transmitter coils in inductive power transfer (IPT) systems. The IPT transmitter coil design targets at achieving homogeneous-flux distribution at the receivers' position, thus, the limited misalignment can be fully countered by passive magnetic design. However, different design effort is expected based on the coil's structure, and corresponding modelling and design methods. In this investigation, we adopted two methodologies for the homo-flux transmitter coil design: one is to derive an analytical solution and the other is to explore a Finite Element Analysis (FEA) based solution. By implementing the genetic algorithm (GA) as the optimization tool, both design methods can generate the optimal structure of transmitter coils. However, different design complexity, calculating efforts and slightly different results are observed. The result evaluation is presented in this paper with finite-element-analysis (FEA) simulation and experimental results. A 6.78 MHz 48V-12V 20W experimental prototype is demonstrated to verify the analysis.