scholarly journals WPT, Recent Techniques for Improving System Efficiency

2021 ◽  
Author(s):  
Mohamed Aboualalaa ◽  
Hala Elsadek ◽  
Ramesh K. Pokharel
Keyword(s):  
Power Transmission ◽  
Coupled Systems ◽  
Transfer Efficiency ◽  
Transmission Range ◽  
Power Transfer ◽  
Wireless Power ◽  
Strongly Coupled ◽  
Received Power ◽  
Power Transfer Efficiency ◽  
Two Parameters

Wireless power transfer (WPT) technologies have received much more attention during the last decade due to their effectiveness in wireless charging for a wide range of electronic devices. To transmit power between two points without a physical link, conventional WPT systems use two coils, one coil is a transmitter (Tx) and the other is a receiver (Rx) which generates an induced current from the received power. Two main factors control the performance of the WPT schemes, power transfer efficiency (PTE) and transmission range. Power transfer efficiency refers to how much power received by the rechargeable device compared to the power transmitted from the transmitter; while transmission range indicates the longest distance between transmitter and receiver at which the receiver can receive power within the acceptable range of power transfer efficiency. Several studies were carried out to improve these two parameters. Many techniques are used for WPT such as inductive coupling, magnetic resonance coupling, and strongly coupled systems. Recently, metamaterial structures are also proposed for further transfer efficiency enhancement. Metamaterials work as an electromagnetic lensing structure that focuses the evanescent transmitted power into receiver direction. Transmitting & Receiving antenna systems may be used for sending power in certain radiation direction. Optimizing the transmitter antenna and receiver antenna characteristics increase the efficiency for WPT systems. This chapter will present a survey on different wireless power transmission schemes.

scholarly journals Power Transfer Efficiency Analysis for Omnidirectional Wireless Power Transfer System Using Three-Phase-Shifted Drive

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2159 ◽  
Author(s):  
Zhaohong Ye ◽  
Yue Sun ◽  
Xiufang Liu ◽  
Peiyue Wang ◽  
Chunsen Tang ◽  
...  
Keyword(s):  
Power Transmission ◽  
Control Mechanism ◽  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Three Phase ◽  
Power Transfer Efficiency ◽  
Computer Emulation ◽  
Receiving Coil

In order to implement the omnidirectional wireless power transfer (WPT), a novel three-phase-shifted drive omnidirectional WPT system is proposed. This system is comprised of three independent phase-adjusted excitation sources, three orthogonal transmitting coils, and one planar receiving coil. Based on the mutual coupling theory, the power transfer efficiency is derived and the corresponding control mechanism for maximizing this efficiency is presented. This control mechanism only depends on the currents’ root-mean-square (RMS) values of the three transmitting coils and simple calculations after each location and/or posture change of the receiving coil, which provides the real-time possibility to design an omnidirectional WPT system comparing with the other omnidirectional systems. In aid of computer emulation technique, the efficiency characteristic versus the omnidirectional location and posture of the receiving coil is analyzed, and the analytical results verify the validity of the control mechanism. Lastly, a hardware prototype has been set up, and its omnidirectional power transmission capacity has been successfully verified. The experimental results show that the wireless power is omnidirectional and it can be effectively transmitted to a load even though its receiving coil moves and/or rotates in a 3-D energy region.

scholarly journals Printed Split-Ring Loops with High Q-Factor for Wireless Power Transmission

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2884
Author(s):  
Jingchen Wang ◽  
Mark Paul Leach ◽  
Eng Gee Lim ◽  
Zhao Wang ◽  
Rui Pei ◽  
...  
Keyword(s):  
Power Transmission ◽  
Transfer Efficiency ◽  
Q Factor ◽  
Power Transfer ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Split Ring ◽  
Spiral Coil ◽  
High Q ◽  
Power Transfer Efficiency

The use of printed spiral coils (PSCs) as inductors in the construction of Wireless Power Transmission (WPT) circuits can save space and be integrated with other circuit boards. The challenges and issues of PSCs present for WPT mainly relate to maintaining an inductive characteristic at frequencies in Ultra High Frequency (UHF) band and to maximising the power transfer efficiency (PTE) between primary and secondary circuits. A new technique is proposed to increase the Q-factor relative to that offered by the PSC, which is shown to enhance WPT performance. This paper provides four-turn planar split-ring loops with high Q-factor for wireless power transmission at UHF bands. This design enhances the power transfer efficiency more than 12 times and allows for a greater transfer distance from 5 mm to 20 mm, compared with a conventional planar rectangular spiral coil.

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.

Power transfer efficiency of magnetic resonance wireless power link with misaligned relay resonator

2012 ◽  
Author(s):  
Ki Young Kim ◽  
Young-Ho Ryu ◽  
Eunseok Park ◽  
Nam Yoon Kim ◽  
Jinsung Choi ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Power Transfer Efficiency

Wireless Power Transfer Systems via Strong Coupled Magnetic Resonances — Design, PCB Implementation and Tests

2011 ◽  
Vol 383-390 ◽  
pp. 5984-5989
Author(s):  
Yan Ping Yao ◽  
Hong Yan Zhang ◽  
Zheng Geng
Keyword(s):  
Printed Circuit Board ◽  
Experimental System ◽  
Wireless Power Transfer ◽  
Circuit Board ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Power Transfer Efficiency ◽  
Coil Winding ◽  
Magnetic Resonances

In this paper, we present theoretical analysis and detailed design of a class of wireless power transfer (WPT) systems based on strong coupled magnetic resonances. We established the strong coupled resonance conditions for practically implementable WPT systems. We investigated the effects of non-ideal conditions presented in most practical systems on power transfer efficiency and proposed solutions to deal with these problems. We carried out a design of WPT system by using PCB (Printed Circuit Board) antenna pair, which showed strong coupled magnetic resonances. The innovations of our design include: (1) a new coil winding pattern for resonant coils that achieves a compact space volume, (2) fabrication of resonant coils on PCBs, and (3) integration of the entire system on a pair of PCBs. Extensive experiments were performed and experimental results showed that our WPT system setup achieved a guaranteed power transfer efficiency 14% over a distance of two times characteristic length(44cm). The wireless power transfer efficiency in this PCB based experimental system was sufficiently high to lighten up a LED with a signal generator.

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