Magnetic Coupler Parameters Optimization for Electric Vehicle Charging System With DQD Coil Structure

This article proposes a solution to address the issue of fluctuating coupling coefficients in wireless power transmission for electric vehicles. The proposed solution involves the utilization of the novel double quadrature D (DQD) magnetic coupler with lightweight magnetic core, which optimizes the structure of the part-coverage magnetic core and incorporates stacked D coils. This approach enhances the coupling performance while minimizing the usage of magnetic core. This article includes mathematical modeling and analysis of the DQD magnetic coupler, as well as the derived output characteristics of the wireless power transfer (WPT) system based on the inductance-capacitance-capacitance-series (LCC-S) compensation topology. In addition, the parameters are optimized to improve coupling capability, anti-offset performance, and overall lightweight design. A comparative analysis is conducted among the coupling coefficient retention capability of the DQD magnetic coupler and other magnetic coupler, highlighting the superior multidirectional antioffset performance of the DQD magnetic coupler. To validate the proposed solution, a 1 kW experimental prototype is constructed and the measured and simulated results demonstrate a consistent agreement, thereby confirming the feasibility of the proposed DQD magnetic coupler to significantly reduce magnetic core.