scholarly journals Double-Coil Dynamic Shielding Technology for Wireless Power Transmission in Electric Vehicles

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5271
Author(s):  
Yuan Li ◽  
Shumei Zhang ◽  
Ze Cheng
Keyword(s):  
Electromagnetic Field ◽  
Electric Vehicles ◽  
Power Transmission ◽  
Wireless Power Transfer ◽  
Transmission Efficiency ◽  
Wireless Power ◽  
Modeling Simulation ◽  
Transmission Distance ◽  
Active Shielding ◽  
Different Levels

During wireless charging, the transmission distance of electric vehicles varies, resulting in different levels of electromagnetic field leakage. An improved active shielding technology, the double-coil dynamic shielding technology, is proposed in this paper for wireless power transfer (WPT) systems with different transmission distances. Modeling, simulation, and experiments are performed for the WPT system with a double-coil dynamic shielding scheme and compared with other cases. The results show that the proposed double-coil dynamic shielding scheme is able to shield approximately 70% of the electromagnetic field leakage for WPT systems at different transmission distances. In addition, it essentially causes no degradation in transmission efficiency (only 3.1%). The effectiveness and feasibility of the proposed scheme are verified.

Network Analysis and Impedance Matching Methods for Wireless Power Transfer via Coupled Magnetic Resonances

2013 ◽  
Vol 437 ◽  
pp. 301-305 ◽  
Author(s):  
Yan Ting Luo ◽  
Yong Min Yang ◽  
Zhong Sheng Chen
Keyword(s):  
Network Analysis ◽  
Power Transmission ◽  
Impedance Matching ◽  
Wireless Power Transfer ◽  
Transmission Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Matching Method ◽  
Transmission Distance ◽  
Magnetic Resonances

Wireless power transfer (WPT) via coupled magnetic resonances has received much attention owing to its high power transmission efficiency at mid-range distance in recent years. In this paper, a novel network method is used to analyze the WPT system. A two-port network model of the system is built and the ABCD parameters of the model are innovatively used to characterize the system. Then the power transmission efficiency is analyzed at different transmission distance. To improve the power transmission efficiency, an impedance matching method is proposed based on the network analysis of the system. In the end, its feasibility is testified by a case study. The results demonstrate that the maximum power transmission efficiency can be achieved by using the impedance matching method proposed in this paper.

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.

Characteristic Research on Wireless Power Transfer Based on Magnetic Coupling Resonant

2014 ◽  
Vol 687-691 ◽  
pp. 3379-3382
Author(s):  
Shui Xiang Cui ◽  
Zhi Juan Zhang ◽  
Xue Mei Liang
Keyword(s):  
Theoretical Analysis ◽  
Power Transmission ◽  
Magnetic Coupling ◽  
Load Resistance ◽  
Transmission Efficiency ◽  
Wireless Power ◽  
Load Power ◽  
Transmission Distance ◽  
Working Principle ◽  
Coil Size

This paper analyses the working principle of magnetic coupling resonant wireless power transmission system based on mutual inductance coil model, and then gets the expressions of load power and transmission efficiency. By the theoretical analysis the relations between the various system parameters such as: coil size, transmission distance, load resistance, the resonant frequency and load power, transmission efficiency are obtained. According to the results of theoretical analysis, the system’s characteristics of load power and transmission efficiency with varying transmission distance are studied. Finally, simulations verify the accuracy of analysis by Matlab/Simulink.

A Review of Methods and Challenges for Improvement in Efficiency and Distance for Wireless Power Transfer Applications

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sokol Kuka ◽  
Kai Ni ◽  
Mohammed Alkahtani
Keyword(s):  
Electric Vehicles ◽  
Power Efficiency ◽  
Near Field ◽  
Electronic Devices ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Inductive Power Transfer ◽  
The Past ◽  
Transmission Distance

AbstractOver the past few years, interest and research in wireless power transfer (WPT) have been rapidly incrementing, and as an effect, this is a remarkable technology in many electronic devices, electric vehicles and medical devices. However, most of the applications have been limited to very close distances because of efficiency concerns. Even though the inductive power transfer technique is becoming relatively mature, it has not shown near-field results more than a few metres away transmission. This review is focused on two fundamental aspects: the power efficiency and the transmission distance in WPT systems. Introducing the principles and the boundaries, scientific articles will be reviewed and discussed in terms of their methods and respective challenges. This paper also shows more important results in efficiency and distance obtained, clearly explaining the theory behind and obstacles to overcome. Furthermore, an overlook in other aspects and the latest research studies for this technology will be given. Moreover, new issues have been raised including safety and security.

scholarly journals An Improved Estimation Method of Mutual Inductance Angle for a Two-Dimensional Wireless Power Transfer System

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 448
Author(s):  
Sangyong Lee ◽  
Jeonho Lee ◽  
Jongkyum Kwon ◽  
Se-Kyo Chung
Keyword(s):  
Power Transmission ◽  
Estimation Method ◽  
Wireless Power Transfer ◽  
Transmission Efficiency ◽  
Mutual Inductance ◽  
Transfer System ◽  
Two Dimensional ◽  
Power Transfer ◽  
Wireless Power ◽  
Wireless Power Transfer System

The improvement of power transmission efficiency (PTE) is an important issue in the design of a wireless power transfer (WPT) system. The WPT system with multiple transmitting (Tx) or receiving (Rx) coils is a way to improve the PTE. This paper deals with the estimation of the mutual inductance angle for a two-dimensional (2D) WPT system with two Tx coils and one Rx coil. The mutual inductance angle is one of the most important parameters to determine the PTE in the 2D WPT system. The condition for the maximum PTE is investigated and the mutual inductance angle is defined for the 2D WPT system. An improved estimation method of the mutual inductance angle is proposed based on the phase-locked loop (PLL) technique using the voltages and currents of the Tx coils. The simulation and experimental results are provided to validate the effectiveness of the proposed method.

scholarly journals Electromagnetic Shielding Techniques in the Wireless Power Transfer System for Charging Inspection Robot Application

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Chaoqun Jiao ◽  
Yang Xu ◽  
Xiang Li ◽  
Xiumin Zhang ◽  
Zhibin Zhao ◽  
...  
Keyword(s):  
Vertical Direction ◽  
Wireless Power Transfer ◽  
Transmission Efficiency ◽  
Electromagnetic Shielding ◽  
Shielding Effect ◽  
Power Transfer ◽  
Wireless Power ◽  
Inspection Robot ◽  
Aluminum Plates ◽  
Active Shielding

Aiming at eliminating the leakage of magnetic fields from the wireless power transfer (WPT) system, the structural and working characteristics of the WPT system for the inspection robot are analyzed and an electromagnetic shielding method combining passive shielding and active shielding is proposed in this paper. Firstly, we simulated the magnetic field distribution of the WPT system in Maxwell. Secondly, passive shielding is configured in the WPT system, and the material, size, and position of the passive shielding are studied. Then, we add active shielding to areas where passive shielding cannot achieve a good shielding effect. Based on the analysis and summary of the two methods, we shield the WPT system in the horizontal direction with the appropriate size and distance of aluminum plate, and in the vertical direction, we use the active shielding coils. Simulation and experimental results show that the scheme only slightly reduces the transmission efficiency of the system (from 80.2% to 77.6%), but the shielding ability is 34.06% higher than that of only aluminum plates. The excellent effect of the proposed shielding method is verified in our experiment.

scholarly journals Design and Analysis of Magnetic Coils for Optimizing the Coupling Coefficient in an Electric Vehicle Wireless Power Transfer System

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4143 ◽  
Author(s):  
Yang Yang ◽  
Jinlong Cui ◽  
Xin Cui
Keyword(s):  
Electric Vehicles ◽  
Coupling Coefficient ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Transmission Efficiency ◽  
Secondary Coil ◽  
Power Transfer ◽  
Wireless Power ◽  
Ferrite Core ◽  
Internal Parameters

Although the wireless power transfer (WPT) system for electric vehicles (EVs) provides numerous advantages, there is still a low coupling coefficient and the misalignment between the primary coil and the secondary coil needs to be solved. In this paper, the transmission efficiency and transmitted power were calculated based on Series-Series (SS) compensation topology. The coupling coefficient is related to the coil parameters and misalignments. A simulation study was carried out to explore the variation in the coupling coefficient for different coil configurations under different air gaps and coil misalignments. Moreover, the influence of the internal parameters of the square coil on the coupling coefficient was further studied. Finally, this paper discusses the influence of ferrite cores with a square coil on the coupling coefficient. The results of this paper show that designing the optimal internal parameters of the square coil and the ferrite core can increase the coupling coefficient between the coils, which can also provide guidelines for the design and optimization of the magnetic coupling coils for a wireless charging system for electric vehicles.

The Application of Electromagnetic Metamaterials for Wireless Power Transfer

2013 ◽  
Vol 873 ◽  
pp. 619-623 ◽  
Author(s):  
Yun Sheng Guo ◽  
Ji Zhou
Keyword(s):  
Equivalent Circuit Model ◽  
Wireless Power Transfer ◽  
Transmission Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
The Third ◽  
Transmission Distance ◽  
Measurement Results ◽  
Set Up ◽  
Electromagnetic Metamaterials

In this paper, the equivalent circuit model of the two-coil wireless power transfer (WPT) is set up. Using this model, the currents in the transmitting and receiving coils, the input and output powers, and the transmission efficiency are discussed. In order to improve the transmission efficiency and distance, the third resonant coil is placed into the space between the transmitting and receiving coils of the WPT system. The measurement results show that this resonant coil which is actually only one unit of the periodic structure meatmaterial can improve not only the transmission distance but also the efficiency.

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