Design and Analysis of a New Inductive Coil With Improved Characteristics Than Conventional Magnetic Couplers

In conventional coil-based wireless power transfer (WPT) systems, achieving strong coupling and maximizing flux path is difficult without increasing coil dimensions. Also, the possibility of avoiding the presence of a null zone region where mutual inductance between coils becomes zero and later increases in the negative is unavoidable. Also, the amount of copper consumed increases the coil resistance, ultimately lowering the quality factor. To work on these issues, this article works on a novel coil design that overcomes the issues above to compete with conventional coils. The proposed coil utilizes circular and square shapes with intermediate coil widths and an optimum number of turns to maximize coupling, flux path support, shift the null zone to the extreme edge of the coil, reduce overall self-inductance, and offer low coil resistance. Thus, increasing the misalignment tolerance against the conventional circular and square coil and offering better performances. In addition, the operational characteristics of coils and its boundary conditions and magnetic field strength are analyzed using ANSYS Maxwell and finite element analysis (FEA). A 400 W system with LCC-S network is used to verify overall said performances at 200 mm air-gap. The maximum dc–dc efficiency thus achieved is
$\sim 93\%$
.