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.

scholarly journals Application of Shielding Coils in Underwater Wireless Power Transfer Systems

2019 ◽  
Vol 7 (8) ◽  
pp. 267
Author(s):  
Wang ◽  
Song ◽  
Mao
Keyword(s):  
Autonomous Underwater Vehicles ◽  
Wireless Power Transfer ◽  
Underwater Vehicles ◽  
Transfer Efficiency ◽  
Maximum Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Power Transfer Efficiency

Underwater wireless power transfer (WPT) technology can enhance the endurance of the autonomous underwater vehicles (AUV). WPT that based on electromagnetic theory will generate eddy current loss (ECL) in seawater. In this paper, we make use of shielding coils to weaken the electromagnetic field (EMF) in seawater, which can reduce ECL and improve the transfer efficiency. Simplified circuit models were proposed to provide an intuitive and comprehensive analysis of the transfer efficiency and the finite element analysis (FEA) was used to simulate the distribution of EMF. We learn that the system with shielding coils performs better when the operating frequency is relatively high by comparing the power transfer efficiency of the underwater WPT systems with and without the shielding, and its maximum efficiency is higher than the system without shielding. The effect of the shielding coils has the similar influence when compared with the metallic plate. While considering the efficiency and weight of coils, the results show that the shielding coils can be used in the underwater WPT system to improve the 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.

scholarly journals A Modified Wireless Power Transfer System for Medical Implants

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1890 ◽  
Author(s):  
Yosra Ben Fadhel ◽  
Sana Ktata ◽  
Khaled Sedraoui ◽  
Salem Rahmani ◽  
Kamal Al-Haddad
Keyword(s):  
Form Factor ◽  
Wireless Power Transfer ◽  
The Body ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Medical Implants ◽  
Wireless Power ◽  
Small Form ◽  
Power Transfer Efficiency ◽  
Small Form Factor

Wireless Power Transfer (WPT) is a promising technique, yet still an experimental solution, to replace batteries in existing implants and overcome the related health complications. However, not all techniques are adequate to meet the safety requirements of medical implants for patients. Ensuring a compromise between a small form factor and a high Power Transfer Efficiency (PTE) for transcutaneous applications still remains a challenge. In this work, we have used a resonant inductive coupling for WPT and a coil geometry optimization approach to address constraints related to maintaining a small form factor and the efficiency of power transfer. Thus, we propose a WPT system for medical implants operating at 13.56 MHz using high-efficiency Complementary Metal Oxide-Semiconductor (CMOS) components and an optimized Printed Circuit Coil (PCC). It is divided into two main circuits, a transmitter circuit located outside the human body and a receiver circuit implanted inside the body. The transmitter circuit was designed with an oscillator, driver and a Class-E power amplifier. Experimental results acquired in the air medium show that the proposed system reaches a power transfer efficiency of 75.1% for 0.5 cm and reaches 5 cm as a maximum transfer distance for 10.67% of the efficiency, all of which holds promise for implementing WPT for medical implants that don’t require further medical intervention, and without taking up a lot of space.

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