Analysis and design of coupling capacitors for contactless capacitive power transfer systems

Abstract

This paper is focused on the analysis and design of the capacitive plates of the capacitive wireless power transfer system. The coupling structure resembles a loosely coupled capacitor. The electric field coupling interface is the most vital part of the wireless technology. The coupling interface determines the capacitance of the coupling capacitors, maximum power transfer, frequency and overall efficiency of the system. The paper is dedicated to understand the behaviour of the system with respect to the structural construction, frequency of operation and factors that affect the power transfer of the system. The various arrangements and configurations of the capacitive power transfer (CPT) are discussed. The important factors affects the value of coupling capacitance are discussed. Based on results obtained from the analysis, a design guide line is laid out for the construction of the coupling capacitors. The design guidelines addresses critical issues such as operational voltage, temperature stability and selection of the dielectric material. The construction of the system is simple, rugged and inexpensive, which makes it a great contender among the other wireless technology.