Inductive Power Transfer (IPT) technology is a promising solution for wireless charging of Electric Vehicles (EVs). Given the expected uptake of IPT technology for both stationary and in motion in-road charging, many technical challenges regarding the electromagnetic field and thermal aspects need to be overcome to generate cost-effective and reliable solutions. One particular design constraint of in-road IPT systems is the occurrence of local increases in temperature during operation due to power losses in the wireless charging pads. In this paper, safe operating conditions of an enclosed wireless power transfer pad within a pavement model were identified. This aspect has been studied less rigorously compared with the electromagnetic design. This paper presents a numerical thermal analysis of a double-D (DD) prototype IPT primary pad based on two possible configurations; flush-mounted or buried, within a model pavement. A coupled electromagnetic-thermal simulation has been developed to aid in the development of thermally robust in-road IPT systems. In order to validate the proposed two-way coupled electromagnetic-thermal Finite Element (FE) simulations, experiments were performed to capture the evolving thermal field within an IPT primary pad under continuous and periodic duty cycles. This method made possible analysis of the heating patterns and so the identification of internal hotspots within an IPT pad in a roading structure. A thermal camera was used to provide detailed surface temperature distributions, while suitable application of non-metallic Fiber Bragg Grating (FBG) sensing technology enabled a robust technique to measure temperatures within the intense magnetic fields of a high frequency wireless power transfer system to be developed. Comparisons at steady state of the pavement surface temperature distribution, as well as point measurements with the pad and sand, demonstrate good accuracy. The maximum steady state surface temperature occurs at the centre of the sand surface where the IPT pad is placed and is approximately 87 °C and 100 °C for buried and flush-mounted pads, respectively. Moreover, for a 2/3 duty cycle loading, the maximum temperature of the pad tended to an average of approximately 76 °C, while at constant operation the average temperature is 105 °C. Therefore, a 5 min cooling period significantly reduced operating temperatures within the studied model IPT system. In the future, the methodologies proposed in this paper can also be used to improve the design of higher power IPT pads by identifying hotspots and maximum thermal stresses and determination of optimal charging patterns for heat dissipation.

感应功率传输（IPT）技术是电动汽车（EV）无线充电的有前途的解决方案。考虑到IPT技术在固定和动态道路充电中的预期采用，必须克服许多与电磁场和热方面有关的技术挑战，以产生具有成本效益和可靠的解决方案。道路IPT系统的一种特殊设计约束是在操作过程中由于无线充电板中的功率损耗而导致局部温度升高。在本文中，确定了路面模型中封闭式无线电力传输垫的安全操作条件。与电磁设计相比，对这一方面的研究不够严格。本文基于两种可能的配置，对双D（DD）原型IPT主焊盘进行了数值热分析。齐平安装或埋入模型路面中。已经开发了耦合的电磁-热模拟来帮助开发坚固的道路IPT系统。为了验证所提出的双向耦合电磁热有限元（FE）模拟，进行了实验以捕获连续和周期性占空比下IPT主焊盘内不断变化的热场。这种方法可以分析加热模式，从而可以识别道路结构中IPT垫内的内部热点。使用热像仪提供详细的表面温度分布，同时，非金属光纤布拉格光栅（FBG）传感技术的适当应用使一种强大的技术能够测量待开发的高频无线电力传输系统的强磁场内的温度。在人行道表面温度分布的稳态下进行比较，以及用垫层和沙子进行点测量，都显示出良好的精度。最高稳态表面温度发生在放置IPT垫的砂面中心，埋入式和平装式垫分别约为87°C和100°C。此外，对于2/3占空比负载，焊盘的最高温度趋于平均约76°C，而在恒定操作下，平均温度为105°C。所以，5分钟的冷却时间显着降低了所研究的IPT模型系统的工作温度。将来，本文提出的方法还可以用于通过识别热点和最大热应力以及确定用于散热的最佳充电方式来改进高功率IPT焊盘的设计。