scholarly journals Folded Spiral Resonator with Double-Layered Structure for Near-Field Wireless Power Transfer

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1581 ◽  
Author(s):  
Takaya Arai ◽  
Hiroshi Hirayama
Keyword(s):  
Layered Structure ◽  
Input Impedance ◽  
Near Field ◽  
Impedance Matching ◽  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Conventional Models ◽  
Resonant Capacitor

In this paper, a folded spiral resonator with a double-layered structure for near-field wireless power transfer is proposed. In near-field wireless power transfer, conjugate impedance matching is important to achieve high transfer efficiency. To achieve maximum available efficiency, it is common to connect a matching circuit to the antenna. However, the loss increases if a matching circuit is used. A coupling inductor with a resonant capacitor has the capability to adjust an imaginary part of the input impedance, whereas the folded spiral resonator has the capability to adjust both the imaginary and real parts of the input impedance. This resonator can achieve the maximum available efficiency without a matching circuit. This paper shows that the folded spiral resonator with a double-layered structure realizes high transfer efficiency compared to conventional models.

scholarly journals Study on impedance matching and maximum wireless power transfer efficiency of circuits with resonant coupling based on simplified S-matrix

2019 ◽  
Vol 16 (11) ◽  
pp. 20190156-20190156 ◽  
Author(s):  
Hiroya Andoh ◽  
Keita Tsuzuki ◽  
Dai Oikawa ◽  
Toko Sugiura ◽  
Takehiko Tsukamoto ◽  
...  
Keyword(s):  
Impedance Matching ◽  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Resonant Coupling ◽  
Power Transfer Efficiency

scholarly journals Wireless power transfer framework for minirobot based on resonant inductive coupling and impedance matching

2020 ◽  
Vol 11 (1) ◽  
pp. 317
Author(s):  
Kin Yun Lum ◽  
Jyi-Shyan Chow ◽  
Kah Haur Yiauw
Keyword(s):  
Impedance Matching ◽  
Wireless Power Transfer ◽  
Good Alternative ◽  
Inductive Coupling ◽  
Transfer Efficiency ◽  
Receiver Coil ◽  
Power Transfer ◽  
Wireless Power ◽  
Transmission Distance ◽  
Transmitter Coil

Minirobots which are under the field of miniature robotics, have a dimension of a few centimetres to even a few millimetres. Conventionally, these small sized robots are usually powered up by batteries. The batteries can take up a lot of space and result in a bulky system. Isolating the energy storage components from the robot itself can provide a good alternative to further down sized the robot. This can be done with the incorporation of wireless power transfer (WPT) technology. However, studies of small-size WPT are usually reported with poor efficiency. The objective of this paper is to present an efficient wireless power transfer framework for the minirobot by employing the resonant inductive coupling together with impedance matching technique. The theory and design process will be discussed. Then, a simple prototyping experiment was conducted to verify the proposed framework. Result showed 35% transfer efficiency had been achieved on a transmission distance of 0.5 cm. The proposed framework had also successfully powered a 4 watts minirobot prototype at about 16% transfer efficiency where its receiver coil was located 3.5 cm above the transmitter coil.

scholarly journals Numerical Study of Non-Radiating Near-Field Wireless Power Transfer System

2021 ◽  
Vol 2015 (1) ◽  
pp. 012170
Author(s):  
E Zanganeh ◽  
M Song ◽  
M Korobkov ◽  
A Evlyukhin ◽  
A Miroshnichenko ◽  
...  
Keyword(s):  
Magnetic Dipole ◽  
Near Field ◽  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Transfer System ◽  
Dipole Mode ◽  
Power Transfer ◽  
Wireless Power ◽  
Power Transfer Efficiency ◽  
Wireless Power Transfer System

Abstract The main challenge in near-field wireless power transfer systems is the increase of power transfer efficiency. It can be achieved by reducing ohmic or radiation losses of the resonators included in the system. In this paper, we propose and investigate numerically a non-radiating near-field wireless power transfer system based on transmitter and receiver implemented as dielectric disk resonators. The transmitter and receiver geometrical parameters are numerically optimized to operate at the frequency of non-radiating state of high refractive index dielectric resonators instead of magnetic dipole mode. Under the non-radiating state, we determine the frequency with almost zero radiation to the far-field. We numerically study the wireless power transfer efficiency as a function of operation distance between the transmitter and receiver and demonstrate that the higher efficiency compared to magnetic dipole mode can be achieved at non-radiating state for a fixed distance due to suppression of the radiation loss.

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.

Basic Study on Improving Power of Wireless Power Transfer via Magnetic Resonance Coupling

2012 ◽  
Vol 459 ◽  
pp. 445-449 ◽  
Author(s):  
Yang Li ◽  
Qing Xin Yang ◽  
Hai Yan Chen ◽  
Xian Zhang ◽  
Liang Jin
Keyword(s):  
Magnetic Resonance ◽  
New Technology ◽  
Near Field ◽  
Impedance Matching ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Basic Study ◽  
Magnetic Resonance Coupling ◽  
Resonance Coupling

Wireless power transfer via magnetic resonance coupling is a new technology which energy can be transferred in the non-radiative near-field. In order to improve its power, We presented a new analysis that yielded critical insight into the design of practical system . The basic study on coils design and impedance matching network for hundreds of watts was presented. Based on these analysis, The wireless power transfer experimental device was designed. Experimental results shows that the power can be transmitted is up to 300W in the distance of 2.3 m, the efficiency is 60%.

scholarly journals Analysis of Fundamental Differences between Capacitive and Inductive Impedance Matching for Inductive Wireless Power Transfer

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 476 ◽  
Author(s):  
Yelzhas Zhaksylyk ◽  
Einar Halvorsen ◽  
Ulrik Hanke ◽  
Mehdi Azadmehr
Keyword(s):  
Magnetic Resonance ◽  
Impedance Matching ◽  
Perfect Match ◽  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Power Transfer Efficiency ◽  
Parameter Ranges ◽  
Smith Chart

Inductive and capacitive impedance matching are two different techniques optimizing power transfer in magnetic resonance inductive wireless power transfer. Under ideal conditions, i.e., unrestricted parameter ranges and no loss, both approaches can provide the perfect match. Comparing these two techniques under non-ideal conditions, to explore fundamental differences in their performance, is a challenging task as the two techniques are fundamentally different in operation. In this paper, we accomplish such a comparison by determining matchable impedances achievable by these networks and visualizing them as regions of a Smith chart. The analysis is performed over realistic constraints on parameters of three different application cases both with and without loss accounted for. While the analysis confirms that it is possible to achieve unit power transfer efficiency with both approaches in the lossless case, we find that the impedance regions where this is possible, as visualized in the Smith chart, differ between the two approaches and between the applications. Furthermore, an analysis of the lossy case shows that the degradation of the power transfer efficiencies upon introduction of parasitic losses is similar for the two methods.

scholarly journals Investigation of Improved Methods in Power Transfer Efficiency for Radiating Near-Field Wireless Power Transfer

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Hesheng Cheng ◽  
Huakun Zhang
Keyword(s):  
Phase Difference ◽  
Near Field ◽  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Power Sources ◽  
Electrically Small Antenna ◽  
Power Transfer Efficiency ◽  
Feeding Sources

A metamaterial-inspired efficient electrically small antenna is proposed, firstly. And then several improving power transfer efficiency (PTE) methods for wireless power transfer (WPT) systems composed of the proposed antenna in the radiating near-field region are investigated. Method one is using a proposed antenna as a power retriever. This WPT system consisted of three proposed antennas: a transmitter, a receiver, and a retriever. The system is fed by only one power source. At a fixed distance from receiver to transmitter, the distance between the transmitter and the retriever is turned to maximize power transfer from the transmitter to the receiver. Method two is using two proposed antennas as transmitters and one antenna as receiver. The receiver is placed between the two transmitters. In this system, two power sources are used to feed the two transmitters, respectively. By adjusting the phase difference between the two feeding sources, the maximum PTE can be obtained at the optimal phase difference. Using the same configuration as method two, method three, where the maximum PTE can be increased by regulating the voltage (or power) ratio of the two feeding sources, is proposed. In addition, we combine the proposed methods to construct another two schemes, which improve the PTE at different extent than classical WPT system.

Sign in / Sign up

Export Citation Format

Share Document