Analysis of the Influence of the Skin Effect on the Efficiency and Power of the Receiver in the Periodic WPT System

The article shows an analysis of the influence of the skin effect on the maximum efficiency and maximum power of a receiver in a wireless power transfer system (WPT). For this purpose, the original solution of the WPT system was used, which contained periodically arranged planar coils. The results concern the multi-variant analysis of the WPT system. The geometry of the coils was taken into account, i.e., the size of coils, the number of turns, as well as the distance between the transmitting and receiving coils. The calculations were carried out over the frequency range of 0.1-1 MHz. In order to analyse the influence of the skin effect on the proposed WPT system, two approaches were used: analytical and numerical. The article analyses the appropriate selection of load impedance in order to obtain maximum efficiency or maximum power of the receiver. In this analysis, the influence of the skin effect on each of the two operating procedures was examined. The obtained analytical and numerical results differed by no more than 0.45%, which confirmed the correctness of the proposed WPT model. Based on the results, it was determined that the greatest influence of the skin effect occurred at 1 MHz. Then, the efficiency decreased by no more than 9%, while in the case of the receiver power decreased by an average of 25%. Detailed analysis shows the influence of the skin effect on the system parameters, and can also be an important element in the design of WPT systems.