Theoretical Analysis of AC Resistance of Coil Made by Copper Clad Aluminum Wires

摘要

In this paper, we propose coils made by copper clad aluminum (CCA) in wireless power transfer (WPT) systems, which show lower AC resistance than Cu ones in a certain range of frequencies. Resistance of CCA or Cu coil is formulated by analysis of the skin effect, proximity effect and a shape factor of the coil which describes intensity of magnetic fields created by applied current in the coil itself. Boundary frequencies of the range where CCA coils are superior to Cu ones and corresponding resistances are quantitatively analyzed. The condition where CCA coils show lower resistance compared to Cu ones is clarified as configuration of coils and operation frequency.