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 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 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.

scholarly journals Wireless power transfer framework for minirobot based on resonant inductive coupling and impedance matching

2020 ◽  
Vol 11 (1) ◽  
pp. 317
Author(s):  
Kin Yun Lum ◽  
Jyi-Shyan Chow ◽  
Kah Haur Yiauw
Keyword(s):  
Impedance Matching ◽  
Wireless Power Transfer ◽  
Good Alternative ◽  
Inductive Coupling ◽  
Transfer Efficiency ◽  
Receiver Coil ◽  
Power Transfer ◽  
Wireless Power ◽  
Transmission Distance ◽  
Transmitter Coil

Minirobots which are under the field of miniature robotics, have a dimension of a few centimetres to even a few millimetres. Conventionally, these small sized robots are usually powered up by batteries. The batteries can take up a lot of space and result in a bulky system. Isolating the energy storage components from the robot itself can provide a good alternative to further down sized the robot. This can be done with the incorporation of wireless power transfer (WPT) technology. However, studies of small-size WPT are usually reported with poor efficiency. The objective of this paper is to present an efficient wireless power transfer framework for the minirobot by employing the resonant inductive coupling together with impedance matching technique. The theory and design process will be discussed. Then, a simple prototyping experiment was conducted to verify the proposed framework. Result showed 35% transfer efficiency had been achieved on a transmission distance of 0.5 cm. The proposed framework had also successfully powered a 4 watts minirobot prototype at about 16% transfer efficiency where its receiver coil was located 3.5 cm above the transmitter coil.

scholarly journals Increase in Robustness against Effects of Coil Misalignment on Electrical Parameters Using Magnetic Material Layer in Planar Coils of Wireless Power Transfer Transformer

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1970 ◽  
Author(s):  
Joao Pinon Pereira Dias ◽  
Masafumi Miyatake
Keyword(s):  
Magnetic Material ◽  
Wireless Power Transfer ◽  
Light Rail ◽  
Receiver Coil ◽  
Power Transfer ◽  
Wireless Power ◽  
Electrical Parameters ◽  
Material Layer ◽  
System A ◽  
Transmitter Coil

Utilization of wireless power transfer in light rail transits is seen as one solution for electrification of lines. The main advantage of this supply system is the reduction of installation; moreover, the alignment between the transmitter coil in the track and the receiver coil in the train should be perfect in order not to affect the power transfer. To reduce the effects of misalignment on the input and output electric parameters of the system, a new planar core and coil design, called hybrid intercore coil, is proposed. The proposed design uses a magnetic material layer between the windings in the inner half of the coil to create a non-uniform magnetic field distribution, which makes the system more robust against the effects of coil misalignment on the system current and voltage. Simulations with finite element method software were conducted to compare designs. The results show that the proposed design is less susceptible to the effects of misalignment and is more efficient. Prototype cores were constructed to verify the simulation results. Measurements show a smaller input overcurrent and output overvoltage when operating in resonance mode. The proposed design reduced the effects of coil misalignment on electrical parameters.

scholarly journals An Inverter Topology for Wireless Power Transfer System with Multiple Transmitter Coils

2019 ◽  
Vol 9 (8) ◽  
pp. 1551 ◽  
Author(s):  
Supapong Nutwong ◽  
Anawach Sangswang ◽  
Sumate Naetiladdanon
Keyword(s):  
Output Voltage ◽  
Wireless Power Transfer ◽  
Detection Algorithm ◽  
Receiver Coil ◽  
Power Transfer ◽  
Wireless Power ◽  
Operation Conditions ◽  
Power Switches ◽  
Transmitter Coil ◽  
Inverter Topology

This paper presents an inverter topology for a wireless power transfer (WPT) system that is intended to reduce the component counts and complexity of the conventional excitation circuit for multiple transmitter coils. The proposed inverter topology requires only (n+2) power switches, where “n” is the number of transmitter coils. An excitation of a proper transmitter coil pattern with regard to the receiver coil position is determined. The output voltage can be regulated through the primary-side control by adjusting the duty cycles of the inverter switches. A detection method of the receiver coil position is presented using the detection switches on the secondary side. The detection algorithm is based on the reflected impedance knowledge and requires only a current sensor on the primary side. A proper transmitter coil pattern is energized to ensure maximum transfer efficiency throughout the operation. The proposed system is experimentally validated on the created 500-watt WPT multi-coil system. After the receiver coil is placed in a designated area, the proper transmitter coil pattern can be automatically selected and energized. The output voltage can be regulated to a desired value under the typical operation conditions, including load change.

scholarly journals Transmitter Module Optimization for Wireless Power Transfer Systems with Single Transmitter to Multiple Receivers

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2928
Author(s):  
Joungha Lee ◽  
Seung Beop Lee
Keyword(s):  
Wireless Power Transfer ◽  
Transfer Efficiency ◽  
Total Power ◽  
Receiver Coil ◽  
Power Transfer ◽  
Wireless Power ◽  
Load Voltage ◽  
Multiple Receivers ◽  
Power Transfer Efficiency ◽  
Transmitter Coil

Most of the coil designs for wireless power transfer (WPT) systems have been developed based on the “single transmitter to a single receiver (S-S)” WPT systems by the empirical design approaches, partial domain searches, and shape optimization methods. Recently, the layout optimizations of the receiver coil for S-S WPT systems have been developed using gradient-based optimization, fixed-grid (FG) representation, and smooth boundary (SB) representation. In this paper, the new design optimization of the transmitter module for the “single transmitter to multiple receivers (S-M)” WPT system with the resonance optimization for the S-M WPT system is proposed to extremize the total power transfer efficiency while satisfying the load voltage (i.e., rated power) required by each receiver and the total mass used for the transmitter coil. The proposed method was applied to an application model (e.g., S-M WPT systems with two receiver modules). Using the sensitivity of design variables with respect to the objective function (i.e., total power transfer efficiency) and constraint functions (i.e., load voltage of each receiver module and transmitter coil mass) at each iteration of the optimization process, the proposed method determines the optimal transmitter module that can maximize the total power transfer efficiency while several constraints are satisfied. Finally, the optimized transmitter module for the S-M WPT system was demonstrated through comparison with experiments under the same conditions as the simulation environment.

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