Zero Voltage Switching Condition in Class-E Inverter for Capacitive Wireless Power Transfer Applications

This paper presents a complete design methodology of Class-E inverter for capacitive wireless power transfer (CWPT) applications, focusing on the capacitance coupling influence. The CWPT has been investigated in this paper, because most literature refers to inductive (IWPT). However, perspective can result lower cost and higher reliability than IWPT, it does not need coils related shields. selected, is single switch with grounded MOSFET source terminal, leads low costs simple control strategy. presented procedure ensures both zero voltage switching (ZVS) derivative (ZDS) conditions at an optimum coefficient, thus enabling high transmission conversion efficiency. novelties proposed method are that output boosted previous papers available literature, operated efficiency, equivalent impedance circuit operate resonance exploited. efficiency have increased by operating 100 kHz so turn-off losses, as well losses inductor capacitors, reduced. closed-form expressions all currents waveforms derived, allows understanding effects coefficient variations ZVS ZDS conditions. analytical estimations validated through several LTSpice simulations experimental results. converter circuit, used analysis, designed simulated, laboratory prototype experimentally tested. 83.5 W optimal featuring 92.5% confirming theoretical simulation results good agreement tests.