High power transfer density and high efficiency 100 MHz capacitive wireless power transfer system

Abstract

This paper introduces a very high frequency (VHF) capacitive wireless power transfer architecture capable of achieving very high power transfer densities and high efficiencies. High power density is achieved using an operating frequency of 100 MHz and through appropriate design of matching networks. High efficiency is achieved using a custom designed half-bridge GaN chip with integrated gate drivers. To validate performance of the proposed architecture, a prototype capacitive wireless power transfer system is built and tested. Experimental results demonstrate that the system transfers 2.5 W of power across a 1 pF capacitive interface at a very high power transfer density of 1.1 W/mm 2 , at close to 90% efficiency.

Misalignment tolerance wireless power transfer system combining inductive and capacitive coupling

“…To achieve high power transfer over a long distance, the working frequency of the CPT system needs to be increased. Now, the working frequency is in several hundred kHz to up to MHz [8][9][10]. Also, the coupler voltage is required to improve to several kV to achieve the kW power transfer level [11].…”

A Review on the Recent Development of Capacitive Wireless Power Transfer Technology

“…It should be pointed out that m and n do not need to be equal, and an asymmetrical circuit topology can also be used to realize a CPT system. In addition, the position of inductor and capacitor can also be swapped, which can results in different system performance [74][75][76][77]. The number of LC cells determines the system power and efficiency, which needs to be optimized according to practical requirements [78].…”

GaN Microwave DC–DC Converters

“…The system achieved a maximum power transfer of 50 W at approximately 50 MHz. In [111], a high power density of 1.1 W/mm 2 is achieved at 2.6 W by WPT at 100 MHz across a 1-pF capacitance. Recently in [112], a 2.4-kW prototype was demonstrated with four 61×61-cm copper plates.…”