Single-contact transmission for the quasi-wireless delivery of power over large surfaces

Abstract

A method of power transmission is proposed that delivers power through the resonance of a helical receiver with its surrounding stray capacitance. The system operates in a quasi-wireless state where power is transferred over a single connection to a surface much larger than the dimensions of the receiver. This ensures high-efficiency energy transfer over large areas without the need of strong coupling electromagnetic fields. Standard power connectors such as tracks, plugs, and cords may be easily replaced with conductive surfaces or objects such as foil sheets, desks, and cabinets. Presently, the method is experimentally demonstrated at the small scale using loads of up to 50 W at an efficiency of 83% with both bare and insulated surfaces. Simple circuit modeling of the system is presented which shows close agreement with experimental results.

A Cuttable Wireless Power Transfer Sheet

“…Power supply sheets are functional 2-D surfaces that provide power to the RXs placed on them. We categorize these researches into two groups: 1) ad-hoc contact DC power supply sheets [13,37,39,42,44,46] and 2) WPT sheets [17,25,26,30,35,38,45]. Ad-hoc contact DC power supply sheets transmit power to RXs via electrodes which establish conductive contact.…”

“…Various approaches towards WPT sheets have been introduced, ranging from inductive power transfer (IPT) [38,43], magnetically coupling resonant wireless power transfer (MCR-WPT) [14,17,25,26], capacitive power transfer (CPT) [8,41], 2-D waveguide power transmission [30,31], quasi-wireless power transfer (Quasi-WPT) [35,45], and so on. In the following, we review previous WPT sheets in terms of wiring topology and system architectures.…”

Electrical excitation of the local earth for resonant, wireless energy transfer

“…To measure F( r) as a function of distance, helical quarterwave receivers were excited in a manner similar to our previous work [27], with the earth surface replacing the aluminum sheets. Such receivers use stray capacitance to complete the electrical circuit and therefore do not require a second electrode for a return.…”

“…In our previous work [27], the surfaces of conducting objects (such as metal foils, desks, and cabinets) also functioned as one plate of a virtual capacitor. By driving these virtual capacitors at the standing-wave resonant frequency of a helical receiver, we were able to wirelessly deliver power to a load anywhere on the surface.…”

Inductor‐Free Wireless Energy Delivery via Maxwell's Displacement Current from an Electrodeless Triboelectric Nanogenerator

“…Meanwhile, to meet the needs of today's mobile electronics, Internet of things, and sensor networks, wireless delivery of electric power is essential for some applications particularly for implantable medical devices and security. Compared to the importance of wireless communication technology, wireless charging technology is also highly desirable to enhance the adaptability and mobility of wireless devices and systems . Although there are three modes of wireless charging technology including electromagnetic induction, magnetic resonance, and radio wave, all of them are rather inefficient and complex …”