scholarly journals Effects of Foreign Metal Object on Soft-Switching Conditions of Class-E Inverter in WPT

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1926 ◽  
Author(s):  
Wenxun Xiao ◽  
Ruigeng Shen ◽  
Bo Zhang ◽  
Dongyuan Qiu ◽  
Yanfeng Chen ◽  
...  
Keyword(s):  
Soft Switching ◽  
Receiver Coil ◽  
Power Transfer ◽  
Wireless Power ◽  
Metal Object ◽  
Transfer Capability ◽  
Transmitter Coil ◽  
Metal Materials ◽  
Simulation Results ◽  
Class E

A foreign metal object will deteriorate the performance of wireless power transfer (WPT) systems and cause insecurity issues. Therefore, the influence principles and rules of foreign metal objects on soft-switching conditions of Class-E inverters and the performance of WPT systems are developed in this paper. The effects of different metal materials on coil parameters at different frequencies and positions are analyzed first, then the effects of foreign metal objects on soft-switching conditions of Class-E inverters and the power transfer capability of WPT systems are investigated. Principle analyses and simulation results demonstrate that there are significantly different effects on the soft-switching conditions and power transfer when a foreign metal object is placed near the transmitter coil or the receiver coil. In addition, the monotonicity of the variation in power transfer also depends on the position of the foreign metal object. Finally, a WPT experimental prototype with a Class-E inverter is implemented to verify the influence principles and rules of foreign metal objects. The experimental results are highly consistent with the principle analyses and simulation results.

scholarly journals Design of 2MHz OOK transmitter/receiver for inductive power and data transmission for biomedical implant

2019 ◽  
Vol 9 (4) ◽  
pp. 2779 ◽  
Author(s):  
Abdelali El Boutahiri ◽  
Mounir Ouremchi ◽  
Ahmed Rahali ◽  
Mustapha El Alaoui ◽  
Fouad Farah ◽  
...  
Keyword(s):  
Data Transmission ◽  
Supply Voltage ◽  
Receiver Coil ◽  
Cmos Process ◽  
Power Transfer ◽  
Biomedical Implant ◽  
Transmitter Coil ◽  
Implant System ◽  
Inductive Power ◽  
Class E

<p>In this work a 2 MHz on-off keying (OOK) transmitter/receiver for inductive power and data transmission for biomedical implant system is presented. Inductive link, driven by a Class E power amplifier (PA) is the most PA used to transfer data and power to the internal part of biomedical implant system. Proposed transmitter consists of a digital control oscillator (DCO) and a class E PA which uses OOK modulation to transfer both data and power to a biomedical implant. In proposing OOK transmitter when the transmitter sends binary value “0” the DCO and PA are turned off. With this architecture and 2 MHz carrier wave we have implemented a wireless data and power transfer link which can transmit data with data rate 1Mbps and bit error rate (BER) of 10-5. The efficiency of power transfer is 42% with a 12.7 uH transmitter coil and a 2.4 uH receiver coil and the power delivered to the load is about 104.7 mW. Proposed transmitter is designed for output power 4.1V. OOK receiver consists of an OOK demodulator, powered by rectified and regulated 5V p-p RF signal across the receiver coil. The supply voltage of proposed voltage regulator is 5 V with 9mV/V line regulation of. All circuits proposed in this paper were designed and simulated using Cadence in 0.18 um CMOS process.</p>

scholarly journals Simulation Analysis of Wireless Power Transfer for Future Office Communication Systems

2019 ◽  
Vol 8 (9S) ◽  
pp. 533-538
Keyword(s):  
Output Power ◽  
Communication Systems ◽  
Wireless Power Transfer ◽  
Secondary Coil ◽  
Receiver Coil ◽  
Input Frequency ◽  
Power Transfer ◽  
Wireless Power ◽  
Primary Coil ◽  
Transmitter Coil

A Wireless Power Transfer system consists of a transmitter coil which is inductively coupled with secondary coil and is popular for wireless charging of future office communication system. Wireless power transfer is used in different applications ranging from mobile chargers to charging stations. In this paper simulation of Wireless Power Transfer for future office communication systems has been conducted over Maxwell 3d of Ansys electromagnetic suite. The input frequency of primary coil is varied from 1kHz -120kHz with respect to the change in resonant capacitance and observed that input frequency between 20kHz-30 kHz, the output power in secondary coil appears to be maximum at variable distances between transmitter coil and receiver coil. There is an improvement of 72% seen in the output power of secondary coil for 25kHz input frequency of primary coil as compared with 40kHz input frequency. This model can be helpful to design future Office Communication systems for charging the mobile phones, Laptops and to turn on the printer wirelessly.

scholarly journals Effect of DC voltage source on the voltage and current of transmitter and receiver coil of 2.5 kHz wireless power transfer

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
A. H. Butar-Butar ◽  
J. H. Leong ◽  
M. Irwanto
Keyword(s):  
Wireless Power Transfer ◽  
Voltage Source ◽  
Receiver Coil ◽  
Power Transfer ◽  
Wireless Power ◽  
Dc Voltage ◽  
Transmitter Coil ◽  
Current Flows ◽  
Set Up ◽  
Field Area

A solenoid supplied by alternating current (AC) voltage generates electromagnetic which has a field area depends on the level of supplied voltage and current flows through the solenoid. The electromagnetic filed can be captured by the other solenoid in the field area. This concept can be applied in a wireless power transfer (WPT) as presented in this paper. The WPT has transmitter coil and receiver coil which each has form of solenoid. The transmitter coil is connected a half bridge circuit to generate AC voltage on the transmitter coil which transferred to the receiver coil. In the experimental set up, the receiver coil is supplied by DC voltage source and it is changed to observe its effect on the voltage and current on the transmitter and receiver coil of the WPT system.

scholarly journals Efficiency Enhancement in a Multi-coil Wireless Power Transfer System

2021 ◽  
Vol 58 (1) ◽  
pp. 3477-3488
Author(s):  
Samuel Afoakwa, Kyei Anim, Young-Bae Jung
Keyword(s):  
Wireless Power Transfer ◽  
Horizontal Displacement ◽  
Transfer Efficiency ◽  
Receiver Coil ◽  
Power Transfer ◽  
Wireless Power ◽  
Coil Array ◽  
Frequency Splitting ◽  
Transmitter Coil ◽  
Splitting Effect

Wireless power transfer technology via magnetic resonance coupling now has significant interest in industry and research with many applications. This paper proposes a linear multiple transmitter coil array (5 coils) for wireless power transfer for added gain and hence higher transfer efficiency in comparison to a single transmitter coil. The frequency splitting effect as a result of the coupling between the resonant transmitter coils due to their close proximity is shown to reduce the transfer efficiency to a receiver. The effect of the array spacing on splitting effect suppression is verified. It is shown that the splitting effect is sup-pressed as the distance between the coils is increased leading to a higher received signal and hence higher efficiency. Proposed horizontal displacement of the middle transmitter coils (2nd and 4th coils) in the coil array is shown to suppress frequency splitting. To further suppress the splitting effect due to the magnetic coupling between the transmitter coils, a multiple transmitter array is proposed with different coil turns. Thus it is shown that designing the multiple coil array with mixed number of coil turns (the 2nd and 4th coils are designed to have different number of turns as compared to the other three coils) causes uniform coupling among the coils reducing and eventually eliminating the splitting effect. Also to increase the efficiency at the receiver coil, displaced stacked coils are introduced on top of the coil array. The pro-posed stacked coil array is demonstrated to improve the transfer efficiency. Using the techniques, the proposed linear array structure achieves a transfer efficiency of 36.9% for a receiver coil at the boresight of the array at a transfer distance of 40 cm.

scholarly journals Design and Analysis of a Novel Magnetic Coupler of an In-Wheel Wireless Power Transfer System for Electric Vehicles

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 332
Author(s):  
Young Jin Hwang ◽  
Jae Young Jang
Keyword(s):  
Electromagnetic Compatibility ◽  
Combustion Engine ◽  
Wireless Power Transfer ◽  
Air Gap ◽  
Receiver Coil ◽  
Power Transfer ◽  
Coupling Coefficients ◽  
Wireless Power ◽  
Transmitter Coil ◽  
Low Efficiency

Electric vehicle (EVs), which use an electric motor, are expected to replace internal combustion engine vehicles. However, to date EVs are not highly attractive to consumers due to their unsatisfactory battery charging characteristics and high cost. In particular, the existing conductive charging method makes it more difficult to spread EVs due to the inconvenience of charging and the risk of electric shock. The wireless power transfer (WPT) system can eliminate all of the charging troubles of EVs. However, the WPT systems in existing EVs have large air gaps between the transmitter coil and the receiver coil, posing a hurdle that prevents success. The large air gap cause issues such as a loose coupling, low efficiency, and troublesome electromagnetic compatibility (EMC). An in-wheel WPT system can serve as a solution to address the issues arising due to the large air gap. In this paper, we propose a magnetic coupler structure of an in-wheel WPT system for EV applications. A design of two coils is introduced, in which the transmitter coil and receiver coil are designed based on a design method. Moreover, the pad structure according to the ferromagnetic core geometry is designed and discussed. The aim of this research is to find a suitable configuration of the magnetic coupler for an in-wheel WPT system. The values of the coupling coefficients according the magnetic coupler structure are determined. This paper is expected to provide a good reference for further research, including work on the manufacturing of a prototype.

scholarly journals A 3D wireless charging cube with externally enhanced magnetic field for extended range of wireless power transfer

2019 ◽  
Vol 6 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Qi Zhu ◽  
Hua Han ◽  
Mei Su ◽  
Aiguo Patrick Hu
Keyword(s):  
Electromotive Force ◽  
Three Dimensional ◽  
Wireless Power Transfer ◽  
Receiver Coil ◽  
Wireless Charging ◽  
Power Transfer ◽  
Wireless Power ◽  
Magnetic Cores ◽  
Transfer Capability ◽  
Extended Point

More mobile devices such as mobile phones and robots are wirelessly charged for convenience, simplicity, and safety, and it would be desirable to achieve three-dimensional (3D) wireless charging with high spatial freedom and long range. This paper proposes a 3D wireless charging cube with three orthogonal coils and supporting magnetic cores to enhance the magnetic flux outside the cube. The proposed system is simulated by Ansoft Maxwell and implemented by a downsized prototype. Both simulation and experimental results show that the magnetic cores can strengthen the magnitude of B-field outside the cube. The final prototype demonstrates that the power transfer distance outside the cube for getting the same induced electromotive force in the receiver coil is extended approximately by 50 mm using magnetic cores with a permeability of 2800. It is found that the magnitude of B-field outside the cube can be increased by increasing the width and the permeability of the magnetic cores. The measured results show that when the permeability of the magnetic cores is fixed, the induced electromotive force in the receiver coil at a point 300 mm away from the center of the cube is increased by about 2V when the width of the magnetic cores is increased from 50 to 100 mm. The increase in the induced electromotive force at an extended point implies a greater potential of wireless power transfer capability to the power pickup.

scholarly journals A comparative study on slim 3-D receiver coil structures for omnidirectional wireless power transfer applications

2019 ◽  
Vol 6 (2) ◽  
pp. 85-96
Author(s):  
Minxin Wu ◽  
Wenxing Zhong ◽  
Siew Chong Tan ◽  
S. Y. R. Hui
Keyword(s):  
Comparative Study ◽  
Mutual Coupling ◽  
Three Dimensional ◽  
Wireless Power Transfer ◽  
Receiver Coil ◽  
Transfer System ◽  
Power Transfer ◽  
Wireless Power ◽  
Transmitter Coil ◽  
Wireless Power Transfer System

AbstractThis paper presents a comparative study on three types of slim coil structures used as a three-dimensional (3-D) receiver in a wireless power transfer system with a planar transmitter coil. The mutual coupling values and their variations between the receiver structures and the transmitter coil are compared under different distances and angular orientations with respect to the transmitter coil. The merits of performance are related to the consistency of the mutual coupling values under different orientations in a range of distances from the transmitter coil. The practical results show that slim 3-D receiver coil structures can be compatible with a planar transmitter coil with reasonably high-mutual coupling.

scholarly journals High Efficiency with Small Coils Area Ratio of Magnetic Resonant Wireless Power Transfer System

2018 ◽  
Vol 2 (6) ◽  
Author(s):  
Thabat Thabet ◽  
John Woods
Keyword(s):  
High Efficiency ◽  
Wireless Power Transfer ◽  
Area Ratio ◽  
Receiver Coil ◽  
Transfer System ◽  
Power Transfer ◽  
Wireless Power ◽  
Flux Lines ◽  
Transmitter Coil ◽  
Wireless Power Transfer System

Wireless power transfer using magnetic resonance requires cutting flux lines generated from the transmitter coil by the receiver coil. This letter shows that an exact one to one coil area ratio or CAR (i.e. primary relative to secondary) is not a pre-condition to obtain high efficiency. It is also shown that high efficiency can be achieved for relatively small CARs by adjustment of the turns ratio. We go on to show that it is possible to achieve a higher energy efficiency than the coil area ratio and the associated flux cut would dictate.

Sign in / Sign up

Export Citation Format

Share Document