Capacitive Power Transfer System Research Articles

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.

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.

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

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

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

Single-Sided Compensation Network Design Method for Capacitive Power Transfer System Considering Coupling Variation

Single-Sided Compensation Network Design Method for Capacitive Power Transfer System Considering Coupling Variation

Multi-band Adaptive Impedance Compensation Methods for Spatially Robust Capacitive Power Transfer Systems

Multi-band 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

Double-sided LC-compensated capacitive wireless power transfer system with admittance-based matching networks

Double-sided LC-compensated capacitive wireless power transfer system with admittance-based matching networks

Efficiency Improvement Under Coupler Misalignment for Dual-Transmitter and Single-Receiver Capacitive Power Transfer System

Efficiency Improvement Under Coupler Misalignment for Dual-Transmitter and Single-Receiver Capacitive Power Transfer System

Erratum to "Single Wire Capacitive Wireless Power Transfer System for Wearable Biomedical Sensors based on Flexible Graphene Film Material".

In [1], this paper was submitted for the Special Issue on Flexible Biomedical Sensors for Healthcare Applications. The paper was instead published in Volume 16, Issue 6, 2022.

Design guideline of capacitive power transfer system to achieve targeted output power

Power transfer capability of the capacitive power transfer (CPT) system is dependent on the dimensions of capacitive coupler, which should be correctly designed to meet the required amount of output power. This paper presents a guideline to design the conductive plates used in CPT system to achieve a targeted output power. For a given operating frequency, resonant inductance, DC input voltage, load resistance, and the air gap between plates, the required cross-sectional area of conductive plates is obtained using this guideline. It has been guided through the design procedure which is explained in detail. A step-by-step guide to design a 5-watts CPT system is demonstrated as a design example. The proposed design guideline is verified by the experiment which shows the closeness between measured and targeted output power. Design error is obtained as low as 3.6 percent.

Load and Coupling Variations Analysis of Capacitive Power Transfer at 6.78MHz Operating Frequency for Biomedical Implantable Device

This paper presents the design and analysis of load and coupling variations for a current Wireless Power Transfer (WPT) technique, known as Capacitive Power Transfer (CPT). Due to its strength, CPT becomes an effective and essential alternative to conservative technique, which is Inductive Power Transfer (IPT). It can compete IPT in industrial demand since it has a small number of component usage, uncomplicated topology, increases electromagnetic interference (EMI) shielding performance and robust to surrounding metallic elements. Class E power amplifier with the presence of π1b matching resonant circuit is applied in this work as a high frequency ac power source since it has the ability to perform dc-to-ac inversion efficiently. It supports the CPT system to attain a maximum power transmission. MATLAB software is used to design and simulate the CPT circuit; and the analysis is made up from the results. This proposed system able to generate 1W of output power by maintaining up to 98% efficiency at 6.78MHz operating frequency for Biomedical Implantable Device application. The analysis of load variation is in the range of 50Ω until 1kΩ; meanwhile for coupling variation is between 1mm to 15mm.

A capacitive power and signal transfer system based on ring-coupler with mitigated inter-channel crosstalk

A capacitive power and signal transfer system based on ring-coupler with mitigated inter-channel crosstalk

A Review of Capacitive Power Transfer Technology for Electric Vehicle Applications

Electric Vehicle (EV) wireless power transfer technology is an excellent solution to propel EVs forward. The existing wireless power transfer technology for EVs based on Inductive Power Transfer (IPT) technology has the drawbacks of large size, high weight, and high eddy current loss, limiting the further application of this technology. Capacitive Power Transfer (CPT) technology, with its advantages of low cost and light weight, has attracted widespread focus in recent years and has great potential in the field of EV wireless power transfer. This paper begins with the principle of CPT, introduces the potential and development history of CPT technology in the field of EV wireless power transfer, and then reviews the coupling mechanism and resonance compensation network of the CPT system to satisfy the requirements of EV wireless power transfer, including the coupling mechanism of EV static power transfer and dynamic power transfer, and the high-performance resonance compensation network to the requirements of EV wireless power transfer. Finally, this paper reviews the existing problems of CPT technology in the field of EV wireless power transfer and summarizes its future development directions.

Investigation of External Factors for Wireless Capacitive Power Transfer Systems

Investigation of External Factors for Wireless Capacitive Power Transfer Systems

Enhanced-efficiency Capacitive Coupling Intra-body Power Transfer Systems with 1.8 V Output for Neural Interfaces.

Traditional wireless power transfer methods for powering neural interfaces have many restrictions such as short transmission distance and strict device alignment. The recently proposed capacitive coupling intra-body power transfer (CC-IBPT) which utilizes human body as the medium supports flexible placements of the transmitter electrode. In this paper, we established two prototype systems based on CC-IBPT with different power sources of a grounded signal generator and a battery-powered board to explore the maximum output power levels with 1.8 V load voltage. To improve the power transmission efficiency, LC impedance matching (IM) and backward compensation (BC) are conducted at the transmitter (TX) and receiver (RX) respectively. Measured results show that 2.5 and 7.4 times load power is enhanced in the two prototype systems. Moreover, the maximum power transfer efficiency (PTE) of 11.16% can be obtained with the TX-RX distance of 16 cm. Therefore, our work verifies CC-IBPT's capability of achieving a high PTE in long-distance wireless power supply for neural interfaces and promotes its widespread application.

A Constant Output Capacitive Wireless Power Transfer System Based on Parity-Time Symmetric

In existing capacitive wireless power transfer (CPT) systems, the coupling capacitance of the traditional couplers is usually small, which will lead to a significant decrease in the power transfer capability when the transfer distance increases. Thus, it is a big challenge to achieve stable output power and constant transfer efficiency under different coupling capacitance. In this work, the circuit model of the CPT system with double-side LC compensation network is established firstly. Then, based on the parity-time (PT) symmetric theory, a primary-side control strategy is presented to achieve stable output power and constant high transfer efficiency when the coupling capacitance changes. Finally, the experimental results show that when the insertion depth of the stack array coupler changes from 60 to 180 mm, the output power of the proposed CPT prototype is almost stable at 25W, and the transfer efficiency is kept at around 88%, which verifies the feasibility and effectiveness of the proposed design.

Power Density Optimization Based Parameter Design Method for the Capacitive Power Transfer System With Magnetic-Core Inductors

Power Density Optimization Based Parameter Design Method for the Capacitive Power Transfer System With Magnetic-Core Inductors