Abstract
Thermal design is particularly important for high-power and compact inductive power transfer (IPT) systems having limited surface area for heat dissipation. This paper presents the thermal design and optimization of a 30 kW IPT system for electric vehicles. An improved analytical thermal model with high accuracy for liquid-cooled magnetic couplers was proposed by using thermal network method (TNM). It considers heating components as well as thermal interface materials. Then multi-objective thermal optimization procedure of the liquid-cooled magnetic coupler was conducted with the presented model. Tradeoffs among temperature rise, weight, and cost were discussed and an optimized solution was selected. The thermal FE models were established and compared with the thermal networks. Subsequently, the thermal performance of the system at different power levels and misaligned conditions was analyzed. The experimental setup based on Fiber Bragg grating sensors was built, and the prototypes were tested with an output power of around 28 kW. The error of stable temperature between the experiment and the prediction was less than 10% at the measurement points, verifying the thermal models. The proposed thermal models and optimization procedure accelerate the thermal design of IPT systems, towards higher power density.