A Comprehensive Investigation of Thermal Risks in Wireless EV Chargers Considering Spatial Misalignment From a Dynamic Perspective

As wireless electric vehicle charging (WEVC) technology moves toward commercialization, understanding its associated risks is crucial, particularly with the trend toward high-power fast charging. In this article, thermal risks and factors exacerbating the risks in wireless electric vehicle chargers are investigated comprehensively, focusing on the magnetic coupler and foreign objects (FOs) intruding on the charging area. The power losses and temperatures of the coupler and FOs are obtained using a two-way electromagnetic-thermal coupled model, and the coupler will be assigned to a risk level according to the proposed four-temperature-level risk evaluation mechanism. In this model, practical considerations include coil types, misalignments, FO materials, ambient temperatures, etc. Moreover, a dynamic perspective is used to characterize the trend of risks so as to provide predictive insights. To validate the newly identified risks, two 6.6-kW WEVC prototypes are built employing circular coils and DD coils, respectively. The experimental studies confirm the necessity of implementing thermal risk management strategies for magnetic coupler under misaligned conditions, such as enhanced cooling, including a wider range of materials for foreign object detection (FOD), expanding the FOD area, and so forth.