Abstract
Wireless power transfer is expected in the use of an electric vehicle. It requires a high efficiency and takes a long distance. In this paper, we propose the use of a litz magnetoplated wire (LMW), which is a copper wire (COW) whose circumference is plated with a magnetic thin film, to improve transmission efficiency. The LMW can reduce resistances due to the proximity effect comparison with the COW and Litz wire (LCW) using COW. The inner diameter of coils is di = 36 mm and their number of turns is n = 8. As a result, the resistances of the COW, LCW and LMW at the frequency f = 6.78 MHz are 1.36 Ω, 1.91 Ω and 0.77 Ω, respectively, which show a reduction of resistance of LMW. The efficiencies of the COW, LCW and LMW at a transmission distance of 18 mm are 85.2%, 79.8% and 89.9%, respectively, which show an increase of efficiency of LMW. The temperature rise values of COW, LCW and LMW at received power 5 W are 14 deg., 17 deg.and 10 deg.respectively, which show a decrease of temperature rise of LMW.
