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

In wireless power transfer systems, transmitter coil and receiver coil geometries considerably influence power transmission efficiency (PTE) and the magnetic field leakage. However, a method to optimize the geometry of both transmitter and receiver coils simultaneously 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 transmitter coil and receiver coil geometries simultaneously. 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 design method is a coil geometry for maximizing PTE and the second design method is 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 coil designed to maximize PTE achieved higher PTE and the coil 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.