Automatic Design of Transmitter and Receiver Coils for Wireless Power Transfer Systems by Using Current Distribution Analysis

In wireless power transfer systems, geometries of a transmitter coil and a receiver coil considerably influence power transmission efficiency (PTE) and the magnetic field leakage. However, a method to simultaneously optimize the geometries of both the transmitter and receiver coils is yet to be devised, and custom design for each electronic device remains unfeasible. In this study, using mesh current distribution analysis, we optimized the current distribution in the design area of the transmitter and receiver coils to simultaneously optimize the geometries of the transmitter coil and the receiver coil. Two types of design methods were devised by using two types of optimization: one to maximize PTE and the other to maximize PTE under cancellation conditions of the magnetic field leakage. The first method designs the coil geometries for maximizing PTE and the second method designs for canceling the magnetic field leakage. Electromagnetic simulations and experimental analysis using a metal three-dimensional printer revealed that the design objectives were accomplished because it was confirmed that the coils designed to maximize PTE achieved higher PTE and the coils designed to cancel the magnetic field leakage achieved lower magnetic field leakage intensity. The results of this study proved that the automatic coil design can become a feasible method in various applications.