Ferrite Plate Multi-Objective Topology Optimization in a Wireless Power Transfer System for UAV Charging

Wireless power transfer (WPT) systems offer a promising solution for automating the charging process and extending the mission duration of unmanned aerial vehicles (UAVs). However, the weight of the WPT system’s receiving part mounted on the UAV can significantly impact its energy consumption and overall performance. In this regard, the ferrite plate is a critical component. While it is necessary for improving magnetic coupling and reducing the stray magnetic field, it also increases weight. Topology optimization (TO) is an effective tool for addressing this challenge and identifying the most suitable shape for the ferrite plate. In this study, a multi-objective topology optimization (TO) approach based on the solid isotropic material with penalization (SIMP) method is employed to design an optimized ferrite plate for the receiver side of a WPT system for UAV charging. The multi-objective optimization, implemented through a weighted-sum formulation, identifies ferrite configurations that maximize mutual coupling while minimizing material usage. Three representative Pareto-optimal designs are fabricated and experimentally validated against a full-ferrite reference plate. The results show that the reference configuration is a dominated solution in the Pareto sense, as equivalent mutual coupling can be achieved with approximately 40% less ferrite material. The trade-off between the resulting reduction in charging efficiency and the decrease in the required flight power due to ferrite reduction is analyzed, further demonstrating the potential of TO to substantially reduce system weight without compromising overall system performance.