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.

Research on Wireless Power Transmission Based on Magnetic Resonance Coupling

2013 ◽  
Vol 811 ◽  
pp. 651-656
Author(s):  
Hao Wang ◽  
An Na Wang ◽  
Qiang Zhao ◽  
Yu Zhang
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Power Transmission ◽  
Coupled Mode Theory ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Coupled Mode ◽  
Magnetic Resonance Coupling ◽  
Resonance Coupling ◽  
Resonance Process

e. The formalism of wireless power transmission is discussed coupled mode theory can be used to describe the resonance process. According to the changing process of input impedance and input current to describe the demarcate of resonant frequency. also demonstrate that loop circuits have an important effect of the resonant magnetic field distribution.

scholarly journals Parameters Optimization for Magnetic Resonance Coupling Wireless Power Transmission

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Changsheng Li ◽  
He Zhang ◽  
Xiaohua Jiang
Keyword(s):  
Magnetic Resonance ◽  
Optimal Design ◽  
Power Transmission ◽  
Parameters Optimization ◽  
Maximum Power ◽  
Coupling Coefficients ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Magnetic Resonance Coupling ◽  
Resonance Coupling

Taking maximum power transmission and power stable transmission as research objectives, optimal design for the wireless power transmission system based on magnetic resonance coupling is carried out in this paper. Firstly, based on the mutual coupling model, mathematical expressions of optimal coupling coefficients for the maximum power transmission target are deduced. Whereafter, methods of enhancing power transmission stability based on parameters optimal design are investigated. It is found that the sensitivity of the load power to the transmission parameters can be reduced and the power transmission stability can be enhanced by improving the system resonance frequency or coupling coefficient between the driving/pick-up coil and the transmission/receiving coil. Experiment results are well conformed to the theoretical analysis conclusions.

scholarly journals Automatic Resonance Compensation for Efficient WPT via Magnetic Resonance Coupling Using Flexible Coils

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5254
Author(s):  
Sousuke Nakamura ◽  
Katsuki Baba ◽  
Takahiro Miyaura
Keyword(s):  
Magnetic Resonance ◽  
Resonant State ◽  
Transmission Efficiency ◽  
Wireless Power ◽  
Transmission Distance ◽  
Living Space ◽  
Magnetic Resonance Coupling ◽  
Resonance Coupling ◽  
Good Potential ◽  
Flexible Coils

With the recent proliferation of mobile and wearable devices, wireless power transfer (WPT) has gained attention as an up-and-coming technology to charge these devices. In particular, WPT via magnetic resonance coupling has attracted considerable interest for day-to-day applications since it is harmless to the human body and has relatively long transmission distance. However, it was difficult to be installed into environment (e.g., utensils and furniture) and flexible objects in the living space since the use of flexible coils leads to the decrease in transmission efficiency due to the collapse of the resonance caused by coil deformation. Therefore, this study proposes an automatic resonance compensation system that automatically compensates the inductance variation caused by coil deformation using a circuit that can electronically control the equivalent capacitance (a capacity control circuit), and thereby maintains the resonant state. An experiment was conducted to verify whether the efficiency was maintained when the coil deformed. The results indicated a transmission efficiency nearly as high as that of the ideal resonant state as well as a highly responsive control, and therefore, the proposed system has a good potential for use in real-world applications.

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