Improved Inductive Coupled Wireless Power Transfer System with Square Coils for Odd Harmonic Reduction in Electric Vehicles

Abstract

This paper proposes a Double-Sided LCL compensation topology with a planar spiral square coil structure. This structure helps in the reduction of odd harmonics in a wireless power transfer system. The square coil has a higher self and mutual inductance and an improved coupling in comparison with the conventional circular coil geometry. The higher the inductance, the higher is the input impedance at odd harmonic frequencies. This will reduce the odd harmonic currents and in turn the magnetic fields. Thus, the Electro- Magnetic Interference is reduced. The benefit of the proposed square coil WPT system is proved by MATLAB scripts programming and simulation. Furthermore, the effect of air gap distance on coupling coefficient, mutual inductance and transmission efficiency is studied. The resonant operating frequency of the proposed Double Sided-LCL square coil system of dimension 600x600mm on both transmitter and receiver sides is taken to be 85KHz.