scholarly journals A Double Helix Flux Pipe-Based Inductive Link for Wireless Charging of Electric Vehicles

2020 ◽  
Vol 11 (2) ◽  
pp. 33
Author(s):  
Young Jin Hwang ◽  
Jong Myung Kim
Keyword(s):  
Electric Vehicles ◽  
High Efficiency ◽  
Double Helix ◽  
Load Resistance ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Inductive Link ◽  
Proposed Model ◽  
Planar Coil ◽  
Power Transfer Efficiency

This paper presents a novel inductive link for wireless power transfer (WPT) system of electric vehicles (EVs). The WPT technology uses an alternating magnetic field to transfer electric power through space. The use of the WPT technology for charging electric vehicle provides an excellent alternative to the existing plug-in charging technology. It has been reported that the inductive link using planar coils such as the circular and rectangular coil are capable of transferring a high power with high efficiency. However, they have a poor tolerance for lateral misalignment, thus their power transfer efficiency decreases significantly with the misalignment. Due to the poor misalignment performance of the planar coil topology, extensive studies have been carried out on the flux pipe topology due to their excellent misalignment tolerance. To address this, in this paper, a novel inductive link using double helix flux pipe topology is proposed. The performances of the inductive link using the proposed double helix flux pipe are analyzed and compared with inductive links using conventional flux pipe. The proposed model has excellent characteristics in terms of the power transfer efficiency and tolerance against misalignments. The proposed model is capable of transferring over 1.6 kW of power with a coil-to-coil efficiency of over 98.5% at a load resistance of 20 Ω.

scholarly journals SERIES-SERIES AND SERIES-PARALLEL COMPENSATION TOPOLOGIES FOR DYNAMIC WIRELESS CHARGING

2021 ◽  
Vol 22 (2) ◽  
pp. 199-209
Author(s):  
Muhammad Amirul Asyraf Roslan ◽  
Nadia Nazieha Nanda ◽  
Siti Hajar Yusoff
Keyword(s):  
Resonance Frequency ◽  
Power Efficiency ◽  
Load Resistance ◽  
Transfer Efficiency ◽  
Wireless Charging ◽  
Power Transfer ◽  
Good Efficiency ◽  
Charging Station ◽  
Power Transfer Efficiency ◽  
Ev Charging

Electric vehicles (EV) have gained worldwide attention since the implementation of a wireless power transfer (WPT) to charge their batteries. With WPT, it can be very convenient for EV to be charged dynamically. Nevertheless, there are some issues in dynamic WPT, such as maintaining the power transfer efficiency. Several factors that lead to these problems include disruption of the alignment and the optimum distance between the transmitter and receiver coils. It is thus contributing to the loss of power efficiency when charging the EV. Not to mention, manufacturers build different specifications of EV charging station for different types of EV models in order to meet customer demands. An incompatible charging device will not utilize EV wireless charging to its maximum potential. Hence, to improve the power output capability as well as stabilizing the maximum power transfer during the charging process, a compensation circuit is added to the system. This article focuses on comparing two available compensation circuits (series-series (SS) topology and series-parallel (SP) topology) under the application of dynamic wireless charging. The simulations are conducted using NI Multisim based on the relationship of power transfer efficiency with resonance frequency, coefficient of coupling, and the load resistance. The WPT efficiency for SP-topology shows that it is sensitive to the change of resonance frequency and coupling coefficient, whereas SS-topology maintains good efficiency during the WPT process. Nonetheless, SS-topology performance suffers efficiency loss when paired with a higher load, while SP-topology acts differently. This article will observe the best conditions on the selected compensation designs for better application in EV charging systems in a moving state. ABSTRAK: Kenderaan elektrik (EV) telah menarik perhatian dunia sejak pelaksanaan alih kuasa wayarles (WPT) bagi mengecas bateri. Melalui WPT, EV lebih mudah kerana ia boleh dicas secara dinamik. Namun, pengecasan dinamik WPT turut mengalami masalah, seperti mengimbang kecekapan pemindahan kuasa. Beberapa faktor yang membawa kepada masalah ini adalah kerana terdapat gangguan penjajaran dan jarak optimum antara gegelung pemancar dan penerima. Kerana ini, ia menyumbang kepada kehilangan kecekapan kuasa semasa mengecas EV. Pengeluar juga membina spesifikasi stesen pengisian EV berlainan mengikut jenis model EV demi memenuhi permintaan pelanggan. Namun, platform pengecas EV yang berbeza, tidak dapat mengecas EV secara wayarles dengan maksimum. Oleh itu, bagi membaiki keupayaan jana kuasa serta menstabilkan pengeluaran kuasa maksimum semasa proses pengecasan, litar gantian ditambah ke dalam sistem. Artikel ini memberi keutamaan pada dua litar gantian berbeza (topologi bersiri (SS) dan siri-selari (SP)) di bawah aplikasi pengecasan wayarles dinamik. Simulasi dibuat menggunakan NI Multisim mengikut kecekapan pemindahan kuasa dengan frekuensi resonan, pekali gandingan dan rintangan beban. Kecekapan WPT bagi topologi-SP menunjukkan ianya sensitif pada perubahan frekuensi resonan dan pekali gandingan. Manakala topologi-SS kekal cekap semasa proses WPT. Walau bagaimanapun, prestasi topologi-SS berkurangan ketika diganding dengan beban besar, begitu juga berbeza bagi topologi-SP. Artikel ini akan mengkaji keadaan terbaik pada reka bentuk gantian terpilih bagi aplikasi EV dalam sistem pengecasan bergerak.

Analytical layout optimization of printed planar coil with variable trace width for inductive wireless power transfer

2021 ◽  
pp. 1-17
Author(s):  
Yuhua Cheng ◽  
Wenyu Kang ◽  
Gaofeng Wang ◽  
Maysam Ghovanloo ◽  
Wenjun Li
Keyword(s):  
Power Transmission ◽  
Layout Optimization ◽  
Consumer Electronics ◽  
Power Transfer ◽  
Wireless Power ◽  
Transmission Distance ◽  
Proposed Model ◽  
Planar Coil ◽  
Power Transfer Efficiency ◽  
Speed Up

In the inductive wireless power transmission (WPT) designs of consumer electronics and implantable devices, the printed planar coil in standard manufacture is commonly used. Layout optimization of the coils is one of the important ways to make the power transmission system more efficient. Varying the trace width and turn-to-turn spacing together for the coils is proposed to optimize the maximum achievable power transfer efficiency (𝜂max). An accurate analytical model for the printed square coils is also established as well to speed up the design process. By virtue of this model, an optimal scaling factor of the trace width and the optimal frequency can be quickly estimated. The proposed model is validated by both the simulations (ANSYS HFSS) and experiments. A WPT link of two planar coils with size of 50 mm × 50 mm × 1 mm, operating at 23 MHz, is optimized by using this methodology. After optimization, the measured 𝜂max of the WPT system is increased from 22.60% to 32.74% at a 100-mm transmission distance.

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 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 Magnetic nozzle radiofrequency plasma thruster approaching twenty percent thruster efficiency

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kazunori Takahashi
Keyword(s):  
Magnetic Field ◽  
Electric Propulsion ◽  
Transfer Efficiency ◽  
Rf Plasma ◽  
Power Transfer ◽  
Rf Power ◽  
Plasma Production ◽  
Magnetic Nozzle ◽  
Plasma Thruster ◽  
Power Transfer Efficiency

AbstractDevelopment of a magnetic nozzle radiofrequency (rf) plasma thruster has been one of challenging topics in space electric propulsion technologies. The thruster typically consists of an rf plasma source and a magnetic nozzle, where the plasma produced inside the source is transported along the magnetic field and expands in the magnetic nozzle. An imparted thrust is significantly affected by the rf power coupling for the plasma production, the plasma transport, the plasma loss to the wall, and the plasma acceleration process in the magnetic nozzle. The rf power transfer efficiency and the imparted thrust are assessed for two types of rf antennas exciting azimuthal mode number of $$m=+1$$ m = + 1 and $$m=0$$ m = 0 , where propellant argon gas is introduced from the upstream of the thruster source tube. The rf power transfer efficiency and the density measured at the radial center for the $$m=+1$$ m = + 1 mode antenna are higher than those for the $$m=0$$ m = 0 mode antenna, while a larger thrust is obtained for the $$m=0$$ m = 0 mode antenna. Two-dimensional plume characterization suggests that the lowered performance for the $$m=+1$$ m = + 1 mode case is due to the plasma production at the radial center, where contribution on a thrust exerted to the magnetic nozzle is weak due to the absence of the radial magnetic field. Subsequently, the configuration is modified so as to introduce the propellant gas near the thruster exit for the $$m=0$$ m = 0 mode configuration and the thruster efficiency approaching twenty percent is successfully obtained, being highest to date in the kW-class magnetic nozzle rf plasma thrusters.

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