A Single-Wire Method of Coupling Interface in Capacitive Power Transfer for Electric Vehicle Wireless Charging System

Quasi-Wireless Capacitive Power Transfer for Wire-Free Robotic Joints

“…Most commonly used WPT technique [18] Capable of high power transmission level (kW) [19] High power transfer efficiency [19,20] Low sensitivity to environmental factors (pollutants and weather) [21] Employs resonance frequency matching of Tx and Rx, which allows for less reliance on alignment [18,19] Range can be extended using intermediate coils that are tuned to the same system's resonant frequency [22,23] Transfer power through metallic materials without significant eddy current losses [19,20,22] Less reliance on Tx and Rx alignment [18] Implementation is often more cost efficient than with IPT systems [20] Most secure WPT methodology due to the safe transmission of sound waves in the required frequency band [21] Resistivity to electromagnetic interference due to the transfer of energy occurring through sound waves [18] Cons Potential of significant eddy current losses [19] Potential for cross-talk due to inductance leakage [23] Challenging to transmit power through objects such as walls [21] Complex systems, potentially consisting of additional matching networks [18] High sensitivity to frequency shifts due to resonance frequency aligned Tx and Rx [18] Bipolar CPT requires many capacitive plates for transmission [18] Single-Wire CPT requires a large counterpoise [14] Normally, lower transmission efficiency and distance than IPT [18,20] Relatively low power transmission levels (mW), often being used in bio-medical devices [18] Hardly explored in robotics due to low transmission efficiency [18] With this in mind, the work presented here aims to create a new method of robotic design that completely removes wiring along and between joints of a robotic chassis. A quasi-wireless capacitive (QWiC) method will be utilized that replaces the large counterpoise requirement of a single-wire CPT system with a small quarter wave resonator (QWR) acting as a Rx, providing a compact method of power transfer over the surface of a robotic chassis.…”

“…A second method of WPT that exists is Capacitive Power Transfer (CPT), where an electric field at high frequency is used to transfer power from one electrode "plate" to another. CPT approaches have two primary configuration methodologies: a bipolar method, where the Tx has two physical plates with a matching two plate Rx [13], and a unipolar (or single-wire) method, which consists of a single Tx plate and a ground plane with the Rx either sharing the Tx ground plane or having a capacitive connection to that ground plane through a counterpoise (a large return plate) [14]. For design of a fully wireless robotic system, the same issues arise that were present in IPT, a need for a bulk of wiring and an inverter between each wireless joint [15][16][17].…”

Modeling High Frequency 13.56 MHz Full Bridge Inverter Based on GaN MOSFET for EV Wireless Charging System

“…At this time, a lot of research is being done on wireless power transfer (WPT) because it can transfer energy without physical contact. Because it is considered more profitable from a security point of view, it is then used for various fields of application [1][2][3][4][5] including for charging cellphone batteries, biomedical implants, and charging electric vehicles (EV) capable of charging systems up to kilowatts. Research related to the charge and discharge battery phenomena 6,7) , considering some heat management of battery pack 8) , energy management for EV system 9) , and microwave propagation 10) has been conducted.…”

Scaling-Factor and Design Guidelines for Shielded-Capacitive Power Transfer

“…Furthermore, much research has been conducted on reducing EF emissions using techniques, such as the single-wire system [14,21,22] and the six-plate coupling-interface method [23]. In the study by [23], the coupler has a thickness of 1.9 cm and a gap of 15 cm.…”