2020 Volume 28 Issue 2 Pages 134-139
High power wireless power transmission coils to be used for an electric vehicle (EV) and the automatic guided vehicle used in the plant (AGV) generally have the litz wire coil is used. The litz wire can reduce the high-frequency loss of the wireless power transmission coil. The smaller the number of strands, the easier it is to manufacture litz wires, but the higher the AC resistance. In addition, coil heat generation reduction and efficiency improvement are required. Therefore, the authors proposed a magnetic tape litz wire coil that reduces AC resistance and improves efficiency by winding magnetic tape around litz wire. The AC resistance was reduced from 73.9 to 64.9 mΩ by winding magnetic tape around the litz wire coil. The power transmission efficiency was improved from 88.4% to 88.9%. Heat generation from 1 kW power transmission was reduced from 64.3 ℃ to 58.1 ℃.
