Hexagon-square hybrid coil design for wireless power tranfer system

Wireless power transfer (WPT) is the energy transmission over an air gap without physical contact. Since this method is clean and reliable, it has been widely used in electric vehicles and different applications nowadays. There is different coil models used in WPT literature. Hybrid square-hexagonal coil structure has been proposed in order to eliminate the coupling coefficient change and thus the decrease in efficiency as a result of the misalignment of the coils, which is one of the most important problems in WPT systems. Compared to the normal square coil structure, this structure is less affected by the coupling coefficient as a result of misalignment in the X and Y axis, and as a result, it has a better efficiency. In our study, first of all, SEA analyzes of the square-hexagonal coil structure and simulations were made in the ANSYS SIMPLORER environment. In addition, a WPT system operating at 50 W, 85 KHz was designed and tested in a laboratory environment. FEA analyzes and experimental application results largely overlap, and accordingly, the coil-to-coil efficiency of our WPT system was 93.5% and the overall efficiency of the system was 87%. The air gap between the two windings is 5 cm and a misalignment from 2 cm to 10 cm in the X and Y axes was made to measure the efficiency of the system, and it was observed that the hybrid square-hexagonal winding structure gave better results.