Capacitive Power Transfer Research Articles

Multi-MHz Inductive and Capacitive Power Transfer Systems With PCB-Based Self-Resonators

Multi-MHz Inductive and Capacitive Power Transfer Systems With PCB-Based Self-Resonators

An Improved Design Method Based on a Multiplate Coupler Structure for Capacitive Power Transfer With Wide Ranges of Misalignment and Loads

An Improved Design Method Based on a Multiplate Coupler Structure for Capacitive Power Transfer With Wide Ranges of Misalignment and Loads

Design of Stabilizing Network for Capacitive Power Transfer Transmitter Operating at Maximum Power Transfer Limiting the Voltage Gain in Resonant Capacitors

Capacitive power transfer (CPT) is a technology that is emerging as an alternative to inductive power transfer (IPT) in applications requiring low to medium power. A great interest has been developed in the implementation of CPT systems in battery charging systems, where a condition to compete with IPT systems is the need to increase the power transfer in the CPT systems without significant losses. This paper puts forth a design methodology for a stabilizing network, which has been applied to a CPT system. This methodology has been developed through impedance analysis of the circuit, in order to achieve maximum power transfer, with total gains of voltage and current reaching a value close to unity. The methodology allows for the calculation of the value of the components of the stabilizing network, which has been designed with the objective of stabilizing the resonant frequency against changes in the capacitance of the transmission plates. To validate the design procedure, an experimental prototype was developed at 25 W and an operational frequency of 1.55 MHz. The results obtained validate the design methodology.

Enhancing efficiency in capacitive power transfer: exploring gap distance and load robustness

In this paper, the capacitive power transfer (CPT) technology is used as an alternative to inductive power transfer (IPT). CPT relies on electric fields that are not sensitive to the presence of any metals, utilizes metal electrodes for power transfer, and is less bulky compared to IPT. The proposed CPT system utilizes a Class-E resonant inverter with a double-sided inductor-capacitor (LC) matching circuit which operates at an optimum load, with a duty cycle, D=0.5 to gain an output power, W and efficiency, η=84.6%. The proposed CPT system enhances the system’s efficiency as compared to the past research while preserving the zero-voltage switching (ZVS) condition within a wider load range from 50 Ω to 1,316 Ω. This paper also shows that the proposed CPT system is less sensitive to load and coupling variations. Finally, the rate of power dissipated at varied load resistances, has been derived successfully to determine the sensitivity level of the proposed CPT systems toward load variations. These equations are then validated by plotting the efficiency graphs based on load and coupling variations.

An Investigation of Implantable Capacitive Coupling Intra-body Power Transfer based on Full-band Loss Compensation

An Investigation of Implantable Capacitive Coupling Intra-body Power Transfer based on Full-band Loss Compensation

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

Robotics is a highly active, multidisciplinary research area with a broad list of applications. A large research focus is to enhance modularity in order to expand kinematic capabilities, lower fabrication time, and reduce construction costs. Traditional wiring within a robot presents major challenges with mobility and long-term maintenance. Designing robotics without wires would make a significant functional impact. This work presents a new application of quasi-wireless capacitive power transfer that investigates impedance matching parameters over a highly resonant, coupled transmission line to achieve efficient power transfer over a robotic chassis. A prototype is developed and its operating metrics are analyzed with regard to the matching parameters.

Primary side control technique for capacitive power transfer system without any wireless feedback

The output voltage of capacitive power transfer (CPT) system will change if the load resistance is varied. This paper presents a method to regulate the output voltage using a controller that is located on the primary side, known as the primary side control technique. It does not require any additional components and wireless feedback, which lowers the cost and complexity of CPT system compared to the conventional control technique. Instead of directly measuring the output voltage on secondary side, it is estimated through the measured capacitor voltage on primary side. Modified sine wave control of the full-bridge inverter is adopted to regulate the output voltage. The proposed control technique is validated by the simulation via PSIM software using the practical parameters of capacitive coupler presented in the literature. Simulation results of the output voltage control against the step change in desired output voltage and load resistance indicate the performance of proposed control technique.

Capacitive Wireless Power Transfer System with a 3D-Functional Coupler for Maintenance-Free Industrial Robots

Capacitive Wireless Power Transfer System with a 3D-Functional Coupler for Maintenance-Free Industrial Robots

Multiband Adaptive Impedance Compensation Methods for Spatially Robust Capacitive Power Transfer Systems

Multiband Adaptive Impedance Compensation Methods for Spatially Robust Capacitive Power Transfer Systems

Design of a Static Capacitive Power Transfer System With Six-Plate Coupler for Electric Vehicle Wireless Charging

Design of a Static Capacitive Power Transfer System With Six-Plate Coupler for Electric Vehicle Wireless Charging

Design of Capacitive Power Transfer System with Small Coupling Capacitance for Wireless Power Transfer

Wireless power transfer systems play an important role in the application of modern power supply technology. Wireless charging has been widely used in portable devices such as smartphones, laptops, and even some medical devices. Higher system efficiency can be achieved while reducing costs. This article describes the design of a capacitive power transfer (CPT) system using the Class-E amplifier method. When the capacitance of the coupling plate is small, the operation of Class-E amplifiers under Zero-Voltage-Switching (ZVS) conditions is very sensitive to their circuit parameters. By adding an additional capacitor to the Class-E amplifier, the coupling capacitance can be increased, resulting in better circuit performance. The high efficiency of the Class-E amplifier is verified by simulation and experimental results.

A Critical Review of Compensation Converters for Capacitive Power Transfer in Wireless Electric Vehicle Charging Circuit Topologies

A Critical Review of Compensation Converters for Capacitive Power Transfer in Wireless Electric Vehicle Charging Circuit Topologies

Capacitive Wireless Power Transfer System with Misalignment Tolerance in Flowing Freshwater Environments

Capacitive Wireless Power Transfer System with Misalignment Tolerance in Flowing Freshwater Environments

Nonisolation Model and Load Virtual-Grounding Design Method for Capacitive Power Transfer System With Asymmetric Four-Plate Coupling Interface

Nonisolation Model and Load Virtual-Grounding Design Method for Capacitive Power Transfer System With Asymmetric Four-Plate Coupling Interface

Modeling, simulation and experimental validation of solid media in capacitive wireless power transfer

Capacitive wireless power transfer (CPT) employs an electric field to transmit energy through a medium. Air is the most often used and a well-understood medium. However, CPT can also bridge other solid media and even benefit from them as the dielectric properties of the medium govern the strength of the capacitive coupling. The parasitic elements of the coupling are influenced by the medium, in particular the leakage resistance. In this work, an analytical model is proposed that quantifies the leakage resistance losses in CPT systems for media. The model is validated by both finite element simulations and experiments on three different media: air, plexiglass and polytetrafluorideethylene (PTFE). As a result, at 1 MHz, the leakage resistance of plexiglass is 6 times higher than that of air while that of PTFE is 1.7 times smaller. This proves that a material with a large dipole moment generates larger losses in the medium which negatively affect system efficiency.

Compact inductive and capacitive combined wireless power transfer system for unmanned aerial vehicle applications

Compact inductive and capacitive combined wireless power transfer system for unmanned aerial vehicle applications

Unified Theory of Series, Parallel and LCL/CLC Resonant Circuits in Inductive Power Transfer and Capacitive Power Transfer

Unified Theory of Series, Parallel and LCL/CLC Resonant Circuits in Inductive Power Transfer and Capacitive Power Transfer

Unified Theory of Non-Resonant and Resonant Circuits in Inductive Power Transfer and Capacitive Power Transfer

Unified Theory of Non-Resonant and Resonant Circuits in Inductive Power Transfer and Capacitive Power Transfer

Analysis and Implementation of Underwater Single Capacitive Coupled Simultaneous Wireless Power and Bidirectional Data Transfer System

Analysis and Implementation of Underwater Single Capacitive Coupled Simultaneous Wireless Power and Bidirectional Data Transfer System

Coupling-Independent Capacitive Wireless Power Transfer With One Transmitter and Multiple Receivers Using Frequency Bifurcation

Coupling-Independent Capacitive Wireless Power Transfer With One Transmitter and Multiple Receivers Using Frequency Bifurcation