Winding Layout Analysis of Planar Spiral Coils and Its Optimization in WPT System

Abstract

Planar spiral coil is widely used in the field of WPT because of their simple structure. Based on high frequency eddy current loss mechanism, the influence of the Proximity effect on the AC resistance of winding is analyzed. It reveals the total loss of coil can be reduced by layering the coil to reduce proximity effect when the ratio of loss due to proximity effect is large and based on which layered staggered winding structure and double laminated winding structure are proposed. This method can reduce the AC resistance and improve the quality factor Q at high frequency. Through simulation, the AC loss of coils based on layered staggered winding structure and double laminated winding structure can be greatly reduced comparing to the traditional coil structure, which verifies the theory analysis to be correct and flexible.