scholarly journals Printed Split-Ring Loops with High Q-Factor for Wireless Power Transmission

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2884
Author(s):  
Jingchen Wang ◽  
Mark Paul Leach ◽  
Eng Gee Lim ◽  
Zhao Wang ◽  
Rui Pei ◽  
...  
Keyword(s):  
Power Transmission ◽  
Transfer Efficiency ◽  
Q Factor ◽  
Power Transfer ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Split Ring ◽  
Spiral Coil ◽  
High Q ◽  
Power Transfer Efficiency

The use of printed spiral coils (PSCs) as inductors in the construction of Wireless Power Transmission (WPT) circuits can save space and be integrated with other circuit boards. The challenges and issues of PSCs present for WPT mainly relate to maintaining an inductive characteristic at frequencies in Ultra High Frequency (UHF) band and to maximising the power transfer efficiency (PTE) between primary and secondary circuits. A new technique is proposed to increase the Q-factor relative to that offered by the PSC, which is shown to enhance WPT performance. This paper provides four-turn planar split-ring loops with high Q-factor for wireless power transmission at UHF bands. This design enhances the power transfer efficiency more than 12 times and allows for a greater transfer distance from 5 mm to 20 mm, compared with a conventional planar rectangular spiral coil.

Efficient Rectenna Circuit for Wireless Power Transmission

2020 ◽  
pp. 57-65
Author(s):  
Anurag Saxena ◽  
Paras Raizada ◽  
Lok Prakash Gautam ◽  
Bharat Bhushan Khare
Keyword(s):  
Resonant Frequency ◽  
Power Transmission ◽  
Numerical Data ◽  
Electrical Energy ◽  
Single Band ◽  
Impedance Bandwidth ◽  
Power Transfer ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Power Transfer Efficiency

Wireless power transmission is the transmission of electrical energy without using any conductor or wire. It is useful to transfer electrical energy to those places where it is hard to transmit energy using conventional wires. In this chapter, the authors designed and implemented a wireless power transfer system using the basics of radio frequency energy harvesting. Numerical data are presented for power transfer efficiency of rectenna. From the simulated results, it is clear that the anticipated antenna has single band having resonant frequency 2.1 GHz. The anticipated antenna has impedance bandwidth of 62.29% for single band. The rectenna has maximum efficiency of 60% at 2.1 GHz. The maximum voltage obtained by DC-DC converter is 4V at resonant frequency.

scholarly journals Wireless Power Transfer Approaches for Medical Implants: A Review

Signals ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 209-229
Author(s):  
Mohammad Haerinia ◽  
Reem Shadid
Keyword(s):  
Power Transmission ◽  
Ultrasonic Method ◽  
Inductive Coupling ◽  
Operating Frequency ◽  
Power Transfer ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Implantable Medical Devices ◽  
Design Elements ◽  
Power Transfer Efficiency

Wireless power transmission (WPT) is a critical technology that provides an alternative for wireless power and communication with implantable medical devices (IMDs). This article provides a study concentrating on popular WPT techniques for IMDs including inductive coupling, microwave, ultrasound, and hybrid wireless power transmission (HWPT) systems. Moreover, an overview of the major works is analyzed with a comparison of the symmetric and asymmetric design elements, operating frequency, distance, efficiency, and harvested power. In general, with respect to the operating frequency, it is concluded that the ultrasound-based and inductive-based WPTs have a low operating frequency of less than 50 MHz, whereas the microwave-based WPT works at a higher frequency. Moreover, it can be seen that most of the implanted receiver’s dimension is less than 30 mm for all the WPT-based methods. Furthermore, the HWPT system has a larger receiver size compared to the other methods used. In terms of efficiency, the maximum power transfer efficiency is conducted via inductive-based WPT at 95%, compared to the achievable frequencies of 78%, 50%, and 17% for microwave-based, ultrasound-based, and hybrid WPT, respectively. In general, the inductive coupling tactic is mostly employed for transmission of energy to neuro-stimulators, and the ultrasonic method is used for deep-seated implants.

scholarly journals Power Transfer Efficiency Analysis for Omnidirectional Wireless Power Transfer System Using Three-Phase-Shifted Drive

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2159 ◽  
Author(s):  
Zhaohong Ye ◽  
Yue Sun ◽  
Xiufang Liu ◽  
Peiyue Wang ◽  
Chunsen Tang ◽  
...  
Keyword(s):  
Power Transmission ◽  
Control Mechanism ◽  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Three Phase ◽  
Power Transfer Efficiency ◽  
Computer Emulation ◽  
Receiving Coil

In order to implement the omnidirectional wireless power transfer (WPT), a novel three-phase-shifted drive omnidirectional WPT system is proposed. This system is comprised of three independent phase-adjusted excitation sources, three orthogonal transmitting coils, and one planar receiving coil. Based on the mutual coupling theory, the power transfer efficiency is derived and the corresponding control mechanism for maximizing this efficiency is presented. This control mechanism only depends on the currents’ root-mean-square (RMS) values of the three transmitting coils and simple calculations after each location and/or posture change of the receiving coil, which provides the real-time possibility to design an omnidirectional WPT system comparing with the other omnidirectional systems. In aid of computer emulation technique, the efficiency characteristic versus the omnidirectional location and posture of the receiving coil is analyzed, and the analytical results verify the validity of the control mechanism. Lastly, a hardware prototype has been set up, and its omnidirectional power transmission capacity has been successfully verified. The experimental results show that the wireless power is omnidirectional and it can be effectively transmitted to a load even though its receiving coil moves and/or rotates in a 3-D energy region.

scholarly journals Wireless Power Transfer between Two Self-Resonant Coils over Medium Distance Supporting Optimal Impedance Matching Using Ferrite Core Transformers

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8540
Author(s):  
Jinwook Kim ◽  
Do-Hyeon Kim ◽  
Jieun Kim ◽  
Young-Jin Park
Keyword(s):  
Equivalent Circuit ◽  
Impedance Matching ◽  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Q Factor ◽  
Power Transfer ◽  
Wireless Power ◽  
Ferrite Core ◽  
Matching Conditions ◽  
Power Transfer Efficiency

An efficient wireless power transfer (WPT) system is proposed using two self-resonant coils with a high-quality factor (Q-factor) over medium distance via an adaptive impedance matching network using ferrite core transformers. An equivalent circuit of the proposed WPT system is presented, and the system is analyzed based on circuit theory. The design and characterization methods for the transformer are also provided. Using the equivalent circuit, the appropriate relation between turn ratio and optimal impedance matching conditions for maximum power transfer efficiency is derived. The optimal impedance matching conditions for maximum power transfer efficiency according to distance are satisfied simply by changing the turn ratio of the transformers. The proposed WPT system maintains effective power transfer efficiency with little Q-factor degradation because of the ferrite core transformer. The proposed system is verified through experiments at 257 kHz. Two WPT systems with coupling efficiencies higher than 50% at 1 m are made. One uses transformers at both Tx and Rx; the other uses a transformer at Tx only while a low-loss coupling coil is applied at Rx. Using the system with transformers at both Tx and Rx, a wireless power transfer of 100 watts (100-watt light bulb) is achieved.

scholarly journals WPT, Recent Techniques for Improving System Efficiency

2021 ◽  
Author(s):  
Mohamed Aboualalaa ◽  
Hala Elsadek ◽  
Ramesh K. Pokharel
Keyword(s):  
Power Transmission ◽  
Coupled Systems ◽  
Transfer Efficiency ◽  
Transmission Range ◽  
Power Transfer ◽  
Wireless Power ◽  
Strongly Coupled ◽  
Received Power ◽  
Power Transfer Efficiency ◽  
Two Parameters

Wireless power transfer (WPT) technologies have received much more attention during the last decade due to their effectiveness in wireless charging for a wide range of electronic devices. To transmit power between two points without a physical link, conventional WPT systems use two coils, one coil is a transmitter (Tx) and the other is a receiver (Rx) which generates an induced current from the received power. Two main factors control the performance of the WPT schemes, power transfer efficiency (PTE) and transmission range. Power transfer efficiency refers to how much power received by the rechargeable device compared to the power transmitted from the transmitter; while transmission range indicates the longest distance between transmitter and receiver at which the receiver can receive power within the acceptable range of power transfer efficiency. Several studies were carried out to improve these two parameters. Many techniques are used for WPT such as inductive coupling, magnetic resonance coupling, and strongly coupled systems. Recently, metamaterial structures are also proposed for further transfer efficiency enhancement. Metamaterials work as an electromagnetic lensing structure that focuses the evanescent transmitted power into receiver direction. Transmitting & Receiving antenna systems may be used for sending power in certain radiation direction. Optimizing the transmitter antenna and receiver antenna characteristics increase the efficiency for WPT systems. This chapter will present a survey on different wireless power transmission schemes.

scholarly journals Maximizing Transfer Efficiency with an Adaptive Wireless Power Transfer System for Variable Load Applications

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1417
Author(s):  
Jung-Hoon Cho ◽  
Byoung-Hee Lee ◽  
Young-Joon Kim
Keyword(s):  
Loading Condition ◽  
Wireless Power Transfer ◽  
Input Voltage ◽  
Transfer Efficiency ◽  
Maximum Efficiency ◽  
Variable Load ◽  
Power Transfer ◽  
Wireless Power ◽  
Variable Loading ◽  
Power Transfer Efficiency

Electronic devices usually operate in a variable loading condition and the power transfer efficiency of the accompanying wireless power transfer (WPT) method should be optimizable to a variable load. In this paper, a reconfigurable WPT technique is introduced to maximize power transfer efficiency in a weakly coupled, variable load wireless power transfer application. A series-series two-coil wireless power network with resonators at a frequency of 150 kHz is presented and, under a variable loading condition, a shunt capacitor element is added to compensate for a maximum efficiency state. The series capacitance element of the secondary resonator is tuned to form a resonance at 150 kHz for maximum power transfer. All the capacitive elements for the secondary resonators are equipped with reconfigurability. Regardless of the load resistance, this proposed approach is able to achieve maximum efficiency with constant power delivery and the power present at the load is only dependent on the input voltage at a fixed operating frequency. A comprehensive circuit model, calculation and experiment is presented to show that optimized power transfer efficiency can be met. A 50 W WPT demonstration is established to verify the effectiveness of this proposed approach.

Sign in / Sign up

Export Citation Format

Share Document