scholarly journals Coupling Independent Operation in Wireless Power Transfer System without Ferrite Usage

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Nattapong Hatchavanich ◽  
Sumate Naetiladdanon ◽  
Anawach Sangswang ◽  
Mongkol Konghirun
Keyword(s):  
Output Power ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Constant Current ◽  
Operating Frequency ◽  
Power Transfer ◽  
Wireless Power ◽  
Current Series ◽  
Power Transfer Efficiency ◽  
Primary Current

The power transfer efficiency and output power of a wireless power transfer (WPT) system are mainly affected by magnetic coupling between the primary and secondary coils. This paper presents a constant-current series-series compensated WPT system. Based on the bifurcation criteria, kcri and Lcri, the splitting zero phase angle (ZPA) frequencies is adopted as the operating frequency. The proposed system remains fully compensated even under coupling variations, and without ferrite. The current and voltage gains at the operating frequency can be estimated through the primary current and voltage. A phase-locked loop circuit is used to track the corresponding ZPA frequency due to the coil positioning variations. Experimental results have shown that the 1-kW of output power with the satisfied efficiency of 96%.

Study on the transmission characteristics of magnetic resonance wireless power transfer system

2017 ◽  
Vol 9 (9) ◽  
pp. 1799-1807
Author(s):  
Xiufang Wang ◽  
Yu Wang ◽  
Yilang Liang ◽  
Guangcheng Fan ◽  
Xinyi Nie ◽  
...  
Keyword(s):  
High Efficiency ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Parameter Extraction ◽  
Magnetic Flux Density ◽  
Power Transfer ◽  
Wireless Power ◽  
Element Analysis ◽  
Practical Applications ◽  
Power Transfer Efficiency

Magnetic coupling resonance wireless power transfer technology has attracted worldwide attention in recent years due to its mid-range, non-radiative, and high-efficiency power transfer. However, in regard to its practical applications, there are still some issues that need to be considered and studied with respect to coil design, such as coil structure, and parasitic parameter extraction. This paper investigated the characteristics of magnetic coupling resonance wireless power transfer systems with different coil structures, including circular coils and rectangular coils arranged in parallel. We calculated the magnetic field distributions and mutual inductances by subdividing the receiving coils and computing the magnetic flux density of each subdivision. The proposed analysis was validated by means of the finite element analysis and the experimental results. We investigated the effects of the coil's structure, and topological structures, on the power transfer efficiency. The results demonstrate that using circular coils in parallel is more advantageous than using rectangular coils.

scholarly journals Optimal design of a wireless power transfer link using parallel and series resonators

2016 ◽  
Vol 3 (2) ◽  
pp. 105-116 ◽  
Author(s):  
Giuseppina Monti ◽  
Alessandra Costanzo ◽  
Franco Mastri ◽  
Mauro Mongiardo
Keyword(s):  
Optimal Design ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Quality Factors ◽  
Coupled Resonators ◽  
Power Transfer Efficiency ◽  
Analytical Formulas ◽  
Parallel Series

The optimal design problem for a wireless power transfer link based on a resonant inductive coupling is addressed in this paper. It is assumed that the magnetic coupling coefficient and the inductor quality factors are known. By employing the conjugate image impedances, the values of the inductances realizing the optimal design with respect to given values of the network input and load impedances are derived. It is demonstrated that there is just one optimal design maximizing both the power delivered to the load and the power transfer efficiency of the link. The four possible schemes corresponding to the use of a parallel or a series arrangement for the two coupled resonators (Parallel-Parallel, Series-Series, Parallel-Series, and Series-Parallel) are considered and discussed. Closed form analytical formulas are derived and validated by circuital simulations.

scholarly journals Analysis and Design of Asymmetric Mid-Range Wireless Power Transfer System with Metamaterials

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1348
Author(s):  
Yingqin Zeng ◽  
Conghui Lu ◽  
Cancan Rong ◽  
Xiong Tao ◽  
Xiaobo Liu ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Power Transmission ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Circuit Board ◽  
Power Transfer ◽  
Wireless Power ◽  
Analysis And Design ◽  
Transfer Distance ◽  
Power Transfer Efficiency

In a wireless power transfer (WPT) system, the power transfer efficiency (PTE) decreases sharply with the increase in transfer distance. Metamaterials (MMs) have shown great potential to enhance PTE in mid-range WPT systems. In this paper, we propose two MM slabs of a 3 × 3 array to enhance the magnetic coupling. The MM unit cell was designed by using square spiral patterns on a thin printed circuit board (PCB). Moreover, the asymmetric four-coil WPT system was designed and built based on the practical application scenario of wireless charging for unmanned devices. The simulation and experimental results show that two MM slabs can enhance power transmission capability better than one MM slab. By optimizing the position and spacing of two MM slabs, the PTE was significantly improved at a mid-range distance. The measured PTEs of a system with two MM slabs can reach 72.05%, 64.33% and 49.63% at transfer distances of 80, 100 and 120 cm. When the transfer distance is 100 cm, the PTE of a system with MMs is 33.83% higher than that without MMs. Furthermore, the receiving and load coils were integrated, and the effect of coil offset on PTE was studied.

scholarly journals Optimization of CC-Coil Design for Wireless Power Transfer System with Series-Series Magnetic Resonance Compensation Technique

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Muhammad Muhaimin Mohd Taib ◽  
◽  
Asmarashid Ponniran ◽  
Keyword(s):  
Magnetic Resonance ◽  
Output Power ◽  
Coupling Coefficient ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Coil Design ◽  
Wireless Power ◽  
Transfer Distance ◽  
Power Transfer Efficiency ◽  
Compensation Technique

This study aims to increase the coupling coefficient of the coils and power transfer efficiency (PTE) of the wireless power transfer (WPT) system. WPT system has a severe issue with the PTE as the transfer distance between the transmitter and receiver increases. Therefore, the transmitter and receiver of the single-circular coil (CC-coil) need to be optimized in geometry to maintain high coupling at an optimum distance. Ferrite and aluminum shielding are also crucial on CC-coil optimization. Implementing the series-series (S-S) magnetic resonance compensation technique can increase the PTE of the WPT system. Therefore, the CC-coil is optimized using Ansys Electronics Desktop and co-simulated with the magnetic resonance circuit using Ansys Twin Builder. The results show that the CC-coils' coupling coefficient increased by 21.38% with the shielding implementation. The maximum optimum transfer distance of 37 mm for horizontal misalignment and 30 mm for vertical misalignment. Implementing the S-S magnetic resonance compensation technique can improve the PTE and output power of the WPT system. The power transmitted also varied with the transfer distance, which caused the system's variation of input impedance. Hence, it is essential to consider the coil design and compensation circuit to achieve high PTE and output power at a higher transfer distance.

scholarly journals Design and analysis of 2-coil wireless power transfer (WPT) using magnetic coupling technique

2019 ◽  
Vol 10 (2) ◽  
pp. 611
Author(s):  
A. Ali ◽  
M.N.M Yasin ◽  
M.F.C. Husin ◽  
N.A.M Ahmad Hambali
Keyword(s):  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Effective Distance ◽  
Spiral Coil ◽  
Single Coil ◽  
Coil Diameter ◽  
Power Transfer Efficiency ◽  
Quality Factor Q

2-coil non-radiative wireless power transfer (WPT) is studied to find the coil diameter ratio to effective distance of power transfer efficiency (PTE). Single circular coil and spiral coil are designed and simulated using CST software to compare the result of coil diameter versus effective distance of PTE by using S<sub>21</sub> value. Accordingly, the quality factor (Q) of both coils are presented as Q factor is one of the parameter that affect the performance of WPT system. The result is promising as the effective distance is more than the coil diameter with (PTE) more than 50% using spiral coil as compare to single coil design.

scholarly journals Optimization of Multiresonant Wireless Power Transfer Network Based on Generalized Coupled Matrix

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Qiang Zhao ◽  
Anna Wang
Keyword(s):  
Optimization Algorithm ◽  
High Efficiency ◽  
Impedance Matching ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Transfer Model ◽  
Power Transfer ◽  
Wireless Power ◽  
Power Transfer Efficiency

Magnetic coupling resonant wireless power transfer network (MCRWPTN) system can realize wireless power transfer for some electrical equipment real-time and high efficiency in a certain spatial scale, which resolves the contradiction between power transfer efficiency and the power transfer distance of the wireless power transfer. A fully coupled resonant energy transfer model for multirelay coils and ports is established. A dynamic adaptive impedance matching control based on fully coupling matrix and particle swarm optimization algorithm based on annealing is developed for the MCRWPTN. Furthermore, as an example, the network which has twenty nodes is analyzed, and the best transmission coefficient which has the highest power transfer efficiency is found using the optimization algorithm, and the coupling constraints are considered simultaneously. Finally, the effectiveness of the proposed method is proved by the simulation results.

scholarly journals Inductive coupling for wireless power transfer and near-field communication

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Christoph Degen
Keyword(s):  
Signal Analysis ◽  
Data Transfer ◽  
Near Field ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Coupling System ◽  
Load Calculation ◽  
Power Transfer Efficiency

AbstractThis paper gives an overview of optimizing wireless power transfer systems using magnetic coupling. Optimization aims to maximize either the power transfer efficiency or the transferred power. The resulting load calculation and matching strategies are revisited. Moreover, the coupling system is described, starting with its equivalent circuit and scattering parameters. In addition to wireless power transfer, communication in RFID and NFC systems and its frequency characteristics and bandwidth issues are highlighted. The focus in this paper is on load modulation for data transfer between a tag and reader. For this purpose, subcarrier voltages are derived using time-domain as well as frequency-domain signal analysis.

Scaling Law of Coupling Coefficient and Coil Size in Wireless Power Transfer Design via Magnetic Coupling

2017 ◽  
Vol 137 (4) ◽  
pp. 326-333
Author(s):  
Chiaki Nagai ◽  
Kenji Inukai ◽  
Masato Kobayashi ◽  
Tatsuya Tanaka ◽  
Kensho Abumi ◽  
...  
Keyword(s):  
Coupling Coefficient ◽  
Scaling Law ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Coil Size

Analysis and Design of EIT-Like Magnetic Coupling Wireless Power Transfer Systems

2021 ◽  
pp. 1-11
Author(s):  
Zhi-Juan Liao ◽  
Qi-Kai Feng ◽  
Chen-Hui Jiang ◽  
Fan Wu ◽  
Chen-Yang Xia ◽  
...  
Keyword(s):  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Analysis And Design

scholarly journals Maximizing Transfer Efficiency with an Adaptive Wireless Power Transfer System for Variable Load Applications

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1417
Author(s):  
Jung-Hoon Cho ◽  
Byoung-Hee Lee ◽  
Young-Joon Kim
Keyword(s):  
Loading Condition ◽  
Wireless Power Transfer ◽  
Input Voltage ◽  
Transfer Efficiency ◽  
Maximum Efficiency ◽  
Variable Load ◽  
Power Transfer ◽  
Wireless Power ◽  
Variable Loading ◽  
Power Transfer Efficiency

Electronic devices usually operate in a variable loading condition and the power transfer efficiency of the accompanying wireless power transfer (WPT) method should be optimizable to a variable load. In this paper, a reconfigurable WPT technique is introduced to maximize power transfer efficiency in a weakly coupled, variable load wireless power transfer application. A series-series two-coil wireless power network with resonators at a frequency of 150 kHz is presented and, under a variable loading condition, a shunt capacitor element is added to compensate for a maximum efficiency state. The series capacitance element of the secondary resonator is tuned to form a resonance at 150 kHz for maximum power transfer. All the capacitive elements for the secondary resonators are equipped with reconfigurability. Regardless of the load resistance, this proposed approach is able to achieve maximum efficiency with constant power delivery and the power present at the load is only dependent on the input voltage at a fixed operating frequency. A comprehensive circuit model, calculation and experiment is presented to show that optimized power transfer efficiency can be met. A 50 W WPT demonstration is established to verify the effectiveness of this proposed approach.

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