Development of high-efficiency capacitive discharge using magnetic resonance wireless power transfer systems

2021 ◽  
Author(s):  
Ju Ho Kim ◽  
Chin-Wook Chung
Keyword(s):  
Magnetic Resonance ◽  
High Efficiency ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Capacitive Discharge

Study on Topology Design of Wireless Power Transfer for Electric Vehicle Based on Magnetic Resonance Coupling

2011 ◽  
Vol 308-310 ◽  
pp. 1000-1003 ◽  
Author(s):  
Hao Qiang ◽  
Xue Liang Huang ◽  
Lin Lin Tan ◽  
Hui Huang
Keyword(s):  
Magnetic Resonance ◽  
Electric Vehicle ◽  
High Efficiency ◽  
Wireless Power Transfer ◽  
High Sensitivity ◽  
Topology Design ◽  
Power Transfer ◽  
Wireless Power ◽  
Magnetic Resonance Coupling ◽  
Resonance Coupling

Wireless power transfer (WPT) is required for the diffusion of Electric Vehicle (EV) because it makes possible the process of automatically charging EV. Magnetic resonance coupling is a new technology for WPT, which can transfer a large amount of energy with high efficiency in middle distance. In this paper the topology design of WPT for EV by using this technology is investigated. Through theoretical analysis we obtain expressions of optimal efficiency with different topologies based on equivalent circuits and define a condition criterion, which is related with load resistance, transmission distance, resonance frequency and coil size. According to the condition criterion we can design the appropriate topology easily to guarantee optimal transmission efficiency. Finally, simulations and experiments show that the defined condition criterion has high sensitivity and the proposed method of designing topology is effective and feasible.

Rollable metamaterial screen for magnetic resonance coupling-based high-efficiency wireless power transfer

2020 ◽  
pp. 1-9
Author(s):  
Woosol Lee ◽  
Yong-Kyu Yoon
Keyword(s):  
Magnetic Resonance ◽  
High Efficiency ◽  
Wireless Power Transfer ◽  
Network Analyzer ◽  
Power Transfer ◽  
Wireless Power ◽  
Magnetic Resonance Coupling ◽  
Power Transfer Efficiency ◽  
Resonance Coupling ◽  
The Magnetic Field

Abstract This paper presents a rollable metamaterial screen for high-efficiency wireless power transfer (WPT) system based on magnetic resonance coupling, which operates at 4.5 MHz. The rollable metamaterial screen with a fully expanded area of 750 mm × 750 mm is located in the middle between transmitter and receiver coils and focuses the magnetic field and, by such a way, significantly improves power transfer efficiency (PTE). The metamaterial screen can be rolled up, e.g. onto the ceiling when it is not used, and thus does not require any designated space for the screen saving space. A WPT system with the rollable metamaterial screen is designed, fabricated, and characterized. Improved PTE is qualitatively and quantitatively verified by light bulb experiments and vector network analyzer measurements. The PTE of the WPT system with the metamaterial screen increases from 36 to 58.52% and 10.24 to 31.36% for the distances between the transmitter and receiver coils 100 and 150 cm, respectively. The effects of lateral and angular misalignments on the PTE of the WPT system are also studied. Obtained results show that the rollable metamaterial screen improves the PTE even at the misaligned condition.

A Solution to Frequency Splitting in Magnetic Resonance Wireless Power Transfer Systems Using Double Sided Symmetric Capacitors

2021 ◽  
Vol 5 (2) ◽  
pp. 6-12
Author(s):  
Thabat Thabet ◽  
John Woods
Keyword(s):  
Magnetic Resonance ◽  
Resonance Frequency ◽  
High Efficiency ◽  
Impedance Matching ◽  
Wireless Power Transfer ◽  
Maximum Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Frequency Tracking ◽  
Tuning Method

The technology of wireless power transfer using magnetic resonance coupling has become a subject of interest for researchers with the proliferation of mobile. The maximum efficiency is achieved at a specific gap between the resonators in the system. However, the resonance frequency splits as the gap declines or gets smaller. Different methods have been studied to improve this such as frequency tracking and impedance matching, including capacitive tuning. However, the system has to maintain the same working frequency to avoid moving out of the license exempt industrial, scientific, and medical (ISM) band; and the efficiency must be as large as possible. In this paper, a symmetric capacitance tuning method is presented to achieve these two conditions and solve the splitting problem. In the proposed method, the maximum efficiency at one of the splitting frequencies is moved to match the original resonance frequency. By comparison to other works, both simulation and experiment show considerable improvements for the proposed method over existing frequency tracking and impedance matching methods. The paper also presents a proposal to apply this method automatically which can achieve wireless charging for electronic applications with high efficiency and through variable distance.

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