Effect of Core Thickness on Coil Loss and Temperature in WPT System

In the magnetic-coupled wireless power transmission system, the magnetic core significantly reduces the magnetic leakage and increases the mutual inductance value. However, it may cause a change of the temperature in the wireless power transmission (WPT) system, resulting in a change of the coil heat loss. Although the magnetic core can improve the quality factor of the coil, the heat loss will decrease the system's efficiency. In this paper, the mutual inductance between coils is derived through the theoretical solution of magnetic vector position. Through theoretical analysis, this paper obtains the inference that the coil loss is proportional to the thickness of the magnetic core on the receiving side, and it also analyzes the reason why the maximum temperature of the system is inversely proportional to the thickness of the magnetic core. Finally, the correctness of the analysis is verified by finite element simulation.