Performance Analysis of Spiral Coils in Coreless and Cored Wireless Charging Systems

Wireless Power Transfer Systems (WPTSs) are essential for efficient electric vehicle (EV) charging, but misalignment and coupling variations often affect performance. This paper focuses on optimizing spiral circular coils for WPTSs by analyzing inductive characteristics and considering misalignments in different orientations. COMSOL simulations and experimental tests validate the proposed design, highlighting the effectiveness of an I-core-based spiral winding configuration in improving the coupling coefficient and avoiding bifurcation phenomena. The results demonstrate the reliability of the design for enhancing WPTS performance.