scholarly journals The Development of Capacitive Power Transfer for Biomedical Implantable Devices

2019 ◽  
Vol 8 (3S2) ◽  
pp. 238-246
Keyword(s):  
Electromagnetic Interference ◽  
Impedance Matching ◽  
Implantable Device ◽  
Capacitive Coupling ◽  
Power Transfer ◽  
Wireless Power ◽  
Inductive Power Transfer ◽  
Zero Voltage Switching ◽  
Biomedical Device ◽  
Zero Voltage

Wireless power transfer using electric and magnetic near-fields has been used in many applications widely, and biomedical implants being one of them. The most commonly used method for powering power wirelessly to biomedical implantable device is using inductive coupling between two mutually-coupled coils. In this paper, a consider new method will be proposed in transferring power for biomedical device which is based on capacitive coupling and known as capacitive power transfer (CPT) system. The main reasons of using this method are the low electromagnetic interference (EMI), can reduce power losses and the abilities to transfer power across metal barriers compared to inductive power transfer. To be specific, in this work, we have designed Class E circuit as an inverter to convert the 12VDC to AC with 1 MHz frequency. The prototype of the capacitive power transfer for implantable application has also been successfully developed with capacitive plate dimensions of 3cmx3cm width per length for receiver plate and 4cmx4cm for transmitter plate, respectively. 5mm thickness of beef separation between the plates is used in this paper. The design specification of this work is accordance to stimulator for peripheral nerve implantable device which only needs 100 mW of power to operate in the CPT system. Overall, the developed CPT system for the biomedical device is able to deliver 76mWatt with 41.43% efficiency. To enhance the efficiency, the impedance matching circuit has been proposed in this work and the prototype is now able to deliver 140mWatt power to the DC load, achieving zero voltage switching (ZVS) waveform and efficiency of 77.5%.

scholarly journals Three-Port Converter for Integrating Energy Storage and Wireless Power Transfer Systems in Future Residential Applications

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 272
Author(s):  
Hyeon-Seok Lee ◽  
Jae-Jung Yun
Keyword(s):  
Energy Storage ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Leakage Inductance ◽  
Zero Voltage Switching ◽  
High Voltage Gain ◽  
Receiving Coil ◽  
Resonant Capacitor ◽  
Zero Voltage

This paper presents a highly efficient three-port converter to integrate energy storage (ES) and wireless power transfer (WPT) systems. The proposed converter consists of a bidirectional DC-DC converter and an AC-DC converter with a resonant capacitor. By sharing an inductor and four switches in the bidirectional DC-DC converter, the bidirectional DC-DC converter operates as a DC-DC converter for ES systems and simultaneously as a DC-AC converter for WPT systems. Here, four switches are turned on under the zero voltage switching conditions. The AC-DC converter for WPT system achieves high voltage gain by using a resonance between the resonant capacitor and the leakage inductance of a receiving coil. A 100-W prototype was built and tested to verify the effectiveness of the converter; it had a maximum power-conversion efficiency of 95.9% for the battery load and of 93.8% for the wireless charging load.

scholarly journals Zero Voltage Switching Condition in Class-E Inverter for Capacitive Wireless Power Transfer Applications

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 911
Author(s):  
Fabio Corti ◽  
Alberto Reatti ◽  
Ya-Hui Wu ◽  
Dariusz Czarkowski ◽  
Salvatore Musumeci
Keyword(s):  
Conversion Efficiency ◽  
Coupling Coefficient ◽  
Design Procedure ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Zero Voltage Switching ◽  
Zero Voltage ◽  
Voltage Switching ◽  
Class E

This paper presents a complete design methodology of a Class-E inverter for capacitive wireless power transfer (CWPT) applications, focusing on the capacitance coupling influence. The CWPT has been investigated in this paper, because most of the literature refers to inductive power transfer (IWPT). However, CWPT in perspective can result in lower cost and higher reliability than IWPT, because it does not need coils and related shields. The Class-E inverter has been selected, because it is a single switch inverter with a grounded MOSFET source terminal, and this leads to low costs and a simple control strategy. The presented design procedure ensures both zero voltage switching (ZVS) and zero derivative switching (ZDS) conditions at an optimum coupling coefficient, thus enabling a high transmission and conversion efficiency. The novelties of the proposed method are that the output power is boosted higher than in previous papers available in the literature, the inverter is operated at a high conversion efficiency, and the equivalent impedance of the capacitive wireless power transfer circuit to operate in resonance is exploited. The power and the efficiency have been increased by operating the inverter at 100 kHz so that turn-off losses, as well as losses in inductor and capacitors, are reduced. The closed-form expressions for all the Class-E inverter voltage and currents waveforms are derived, and this allows for the understanding of the effects of the coupling coefficient variations on ZVS and ZDS conditions. The analytical estimations are validated through several LTSpice simulations and experimental results. The converter circuit, used for the proposed analysis, has been designed and simulated, and a laboratory prototype has been experimentally tested. The experimental prototype can transfer 83.5 W at optimal capacitive coupling with operating at 100 kHz featuring 92.5% of the efficiency, confirming that theoretical and simulation results are in good agreement with the experimental tests.

Design and Analysis of Capacitive Power Transfer System with and without the Impedance Matching Circuit

2017 ◽  
Vol 8 (3) ◽  
pp. 1260
Author(s):  
F.K.A. Rahman ◽  
Shakir Saat ◽  
Yusmarnita Yusop ◽  
Huzaimah Husin ◽  
Y. Aziz
Keyword(s):  
Impedance Matching ◽  
Capacitive Coupling ◽  
Attractive Alternative ◽  
Transfer System ◽  
Power Transfer ◽  
Receiver Side ◽  
Wireless Power ◽  
Metallic Elements ◽  
Matching Network ◽  
Resonant Inverter

This paper presents the design and analysis of a relatively new wireless power transfer technique using capacitive coupling, named Capacitive power transfer (CPT). In general, CPT system has been introduced as an attractive alternative to the former inductive coupling method. This is because CPT uses lesser number of components, simpler topology, enhanced EMI performance and better strength to surrounding metallic elements. In this work, aluminium sheet is used as a capacitive coupling at transmitter and receiver side. Moreover, a Class-E resonant inverter together with π1a impedance matching network has been proposed because of its ability to perform the dc-to-ac inversion well. It helps the CPT system to achieve maximum power transfer. The CPT system is designed and simulated by using MATLAB/Simulink software. The validity of the proposed concept is then verified by conducting a laboratory experimental of CPT system. The proposed system able to generate a 9.5W output power through a combined interface capacitance of 2.44nF, at an operating frequency of 1MHz, with 95.10% efficiency. The proposed CPT system with impedance matching network also allows load variation in the range of 20% from its nominal value while maintaining the efficiency over 90%.

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