Effect of coil geometry and shielding on wireless power transfer system

Abstract

Magnetic resonance coupling (MRC) based wireless power transfer (WPT) system is recognized as an efficient and promising technology for safe, convenient and elegant charging solution for various electronic portable devices. MRC technology helps in transferring power wirelessly from transmitter to receiver over larger distances. However in such loosely coupled systems, low power transfer efficiency is the major issue in comparison to conventional wired charging systems. The paper presents detailed analysis of power transfer efficiency between two independent coils separated by distance of 15 cm. The analysis involves an effect of coil geometrical dimensions on power transfer efficiency and mutual inductance between transmitter (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> ) and receiver coils (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> ). In addition, the investigations are further extended to analyze the role of shielding and effect of shielding geometry on power transfer efficiency and mutual inductance between the two coils.