Extending Wireless Power Transfer Distance using Electromagnetic Halbach Array

In this paper, an electromagnetic Halbach array is proposed to extend the wireless power transfer distance. A Halbach array is a special permanent magnets arrangement where one side of the arrangement is stronger, and the other side weaker. The proposed system generates a single-sided AC electromagnetic field using five identical square coils connected in series. With simulation and experimental verification, a single-sided electromagnetic Halbach array for WPT have been designed, and the overall power transfer efficiency (PTE) and power transfer distance have been improved. Experimentally, although the both systems showed high PTE at distance <5 mm, the two-coil system drops below 40% as the proposed system maintained a 40% PTE at maximum distance of 20 mm, which is 4 times greater than the two-coil system. This is a notable improvement in the WPT system.