Compensating Resonant Frequency via Adjusting Adjustable Coil Automatically

2019 ◽  
Vol 12 (5) ◽  
pp. 432-438
Author(s):  
Jin Xu ◽  
Yuting Zhao
Keyword(s):  
Resonant Frequency ◽  
Power Transmission ◽  
Reference Value ◽  
Transmission Efficiency ◽  
Theoretical Research ◽  
Future Research ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Resonant Coupling ◽  
Transmission Distance

Background: Detuning is the main problem that affects the efficiency and transmission distance of the resonant coupling Wireless Power Transmission (WPT). The distance of load and the offset of the load position could cause serious detuning. Methods: This paper presents an adjustable coil in which inductance can be adjusted. Then a model of WPT was established that could compensate resonant frequency automatically using the adjustable coil. Next, the relationship between the primary resonant frequency and the transmission efficiency is analyzed from the circuit. The analysis proved that the design of the adjustable coil could improve the transmission efficiency of the WPT system. Finally, a prototype of WPT system was built. Results: The experimental results showed that WPT system with adjustable coil can improve the transmission efficiency which proves the theoretical research. At the same time, it has essential reference value for the future research of WPT. Conclusion: In this paper, aiming at the system detuning caused by some other factors, such as the position shift of the load during the wireless power transmission, an adjustable coil is proposed.

scholarly journals Optimization for Compact and High Output LED-Based Optical Wireless Power Transmission System

Photonics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 14
Author(s):  
Mingzhi Zhao ◽  
Tomoyuki Miyamoto
Keyword(s):  
Electromagnetic Interference ◽  
Power Transmission ◽  
Light Emitting Diode ◽  
Transmission Efficiency ◽  
Optical Wireless ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Long Distance ◽  
Transmission Distance ◽  
Led Array

Optical wireless power transmission (OWPT) is a technology that supplies energy remotely. Due to the great advantages of long transmission distances, high directionality, no electromagnetic interference noise, and loose safety regulations, light emitting diode (LED) based OWPT systems become appropriate candidates for powering various applications, especially for the Internet of things (IoT). In this paper, improved LED-OWPT systems are proposed based on a collimation scheme for optimizing the system dimension and output. In a single LED configuration, the system dimension is compressed by 46% while the high transmission efficiency is maintained. As for the LED-array system, the dimension is compressed by 56%, and the output is enhanced by 40%. In the experiment, a high electricity output of 532 mW is achieved at 1 m transmission distance. In addition, the effect of misalignment between LED and lens and the potential of long-distance transmission are clarified in the LED-array OWPT system.

scholarly journals Design of High-Power High-Efficiency Wireless Charging Coils for EVs with MnZn Ferrite Bricks

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Yuyu Zhu ◽  
Zuming Wang ◽  
Xin Cao ◽  
Li Wu
Keyword(s):  
High Power ◽  
High Efficiency ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Wireless Transmission ◽  
Wireless Charging ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Quality Factors ◽  
Transmission Distance

In wireless power transmission systems, the inductance, equivalent resistance, and quality factors of the coils are the main factors that influence the system’s transmission efficiency. When designing high-power wireless charging coils for electric vehicles (EVs), ferrite bricks that increase magnetic flux can be selected to increase the self-inductance of the coils, improving the wireless transmission distance and transmission efficiency. In this paper, the effects of the ferrite bricks, the size of the coils, the charging distance, and many other factors in real applications have been extensively studied. After theoretical analysis and simulation, the wireless transmission system has been fabricated and measured. The measured and simulated results are in good agreement. High-power high-efficiency wireless power transmission has been achieved for EVs compared with many other previous literatures.

scholarly journals Wireless power transfer system based on frequency and impedance matching hybrid adjustment against system detuning

2021 ◽  
Vol 2108 (1) ◽  
pp. 012035
Author(s):  
Zhengnan Yuan ◽  
Pengcheng Fu ◽  
Guangshuai Lu ◽  
Pengfei Cao
Keyword(s):  
Magnetic Resonance ◽  
Power Transmission ◽  
Impedance Matching ◽  
Transmission Efficiency ◽  
Resonant Circuit ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Transmission Distance ◽  
Magnetic Resonance Coupling ◽  
Resonance Coupling

Abstract System detuning caused by a variation in the distance between the transmitting and receiving terminals can greatly reduce the transmission power and efficiency of a magnetic resonance-coupled wireless power transmission (WPT) system, which limits the WPT application scope. This paper proposes a magnetic resonance coupling wireless power transmission system, which is based on jointly and continuously adjustable frequency compensation (CAFC) and two-transistor-controlled variable capacitor circuits (TCVCs). Therefore, this system can reach the resonant state by using CAFC and two-TCVCs when the transmission distance is changed. The proposed system can adaptively adjust combinations of the operating frequency and equivalent compensation capacitor’s capacitance to achieve impedance matching avoiding the phase difference caused by the imaginary part of the impedance, thus maintaining stable transmission efficiency under the condition of transmission distance variation. Compared to the traditional magnetic coupled resonant circuit based on impedance matching or variable resonant frequency, the proposed system achieves higher efficiency and stability and dynamic distance adaptation.

scholarly journals Research on the efficiency of single-wire power transmission

2021 ◽  
Vol 2121 (1) ◽  
pp. 012010
Author(s):  
Fei Zhang ◽  
Jing Guo ◽  
Jingming Wang ◽  
Xiaoying Ren ◽  
Lu Gao ◽  
...  
Keyword(s):  
Normal Distribution ◽  
Power Transmission ◽  
Gaussian Function ◽  
Transmission Efficiency ◽  
Theoretical Research ◽  
Wireless Power ◽  
Response Distribution ◽  
Single Wire ◽  
Transmission Distance ◽  
The Relationship

Abstract With the development of related theoretical research on Single Wire Power Transfer(SWPT), the SWPT system has demonstrated its advantages in a variety of special environments. In this paper, the influence of capacitance and inductance on transmission efficiency is studied in order to improve the transmission efficiency of swpt system. This article simplifies and analyzes the circuit model of the SWPT system. It can be found that the system is a second-order circuit, and its response distribution trend conforms to the Gaussian function distribution. There should be an optimal ratio between the capacitor and the inductance to maximize the circuit response. Through the influence of different capacitance, inductance, and transmission distance on transmission efficiency, multiple sets of experiments and simulations are carried out. The experiment found that the capacitance, inductance, and transmission efficiency are in accordance with the Gaussian non-normal distribution, and the acquired data is fitted by the Gaussian function. The average relative error of the fitting is less than 1% under different transmission distances, which can be better reflect the relationship between the three. The study of single-wire power transmission system will provide a key reference for wireless power transmission.

Analysis of Wireless Energy Transfer System Using Magnetic Resonant Coupling

2012 ◽  
Vol 591-593 ◽  
pp. 1164-1167
Author(s):  
Wei Xin Li ◽  
He Zhang
Keyword(s):  
Resonant Frequency ◽  
Power Transmission ◽  
Transmission System ◽  
Simulation Software ◽  
Maximum Efficiency ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Transmission Characteristics ◽  
Resonant Coupling ◽  
Power Transmission System

In order to research the relationship between coupling distance and transmission efficiency, study on the transmission characteristics of magnetic resonant coupling for wireless power transmission system, simulation model of wireless power transmission system via magnetic resonance coupling were established based on the theory of two ports network analysis method. The frequency expression of maximum efficiency and the resonant frequency splitting phenomenon condition of a contact-less power transmission system were derived. In a weak coupling at resonance, magnetic resonant coupling can transfer energy with high efficiency. The resonant frequency changes from two to one depending on the critical condition. Until a certain distance, maximum efficiencies are not got. The transmission characteristics of this system were researched by simulation software and experiments. The results show that the transmission characteristics are consistent with theoretical analysis and simulation.

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.

Sign in / Sign up

Export Citation Format

Share Document