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1
Yunus, A. M. Shiddiq, Apollo Apollo, Muhammad Ruswandi Djalal, and Ahmed Abu-Siada. "Characteristic of Current Diffusion on Double-Plate Conductor for Smaller Resistive Load." EPI International Journal of Engineering 2, no. 1 (2019): 56–60. http://dx.doi.org/10.25042/epi-ije.022019.10.
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Power transmission line is one of the pivotal parts of a power system. It connects power generation house with the consumer even in the long distances. Research on current diffusion on the conductor is inevitable to maximize the power dispatch on transmission line. The main purpose of this study is to recognize the behaviors and characteristics of current diffusion in double-plates conductor for further development in the future. The research outcomes would be very useful, particularly in the transmission line study. In this paper, study will be focused on the characteristic of current diffusion in conductor due to its variation impedance value of load particularly when resistive load is smaller than the conductor impedance (Zo). This research is conducted by experimental test and carried out through extensive simulation using MATLAB and Visual Basic Program in MS. Excel. Poynting theory is employed as a validation approach. The simulation and experiment results show that if RL is smaller than the line impedance Zo, deficiency current establish will occur where the electromagnetic energy is not sufficient for the load.
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Daw, Hnin Yu Lwin, and Hla Myo Htay U. "Design of 230 kV Twin Bundle Double Circuit Overhead Transmission Line." International Journal of Trend in Scientific Research and Development 3, no. 5 (2019): 1967–70. https://doi.org/10.5281/zenodo.3591731.
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The purpose of this paper is to study and design of 230 kV twin bundle double circuit overhead transmission line. In design consideration, the selection of economic voltage, choice of conductor size, number of insulators, maximum sag of conductor and minimum height of conductor are considered. The electrical transfer of energy from one place to another over long distance with standard regulations is one of the major problems in the field of electrical power engineering. The parameters of overhead transmission line are resistance, inductance and capacitance. The bundle conductors are used for reducing the reactance on the line, corona losses, radio interference and surge impedance. Daw Hnin Yu Lwin | U Hla Myo Htay "Design of 230 kV Twin Bundle Double Circuit Overhead Transmission Line" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27830.pdf
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Yamaoka, Masaru, and Jun Hasegawa. "Numerical Calculation of Overhead Transmission Line Galloping by Double Conductor Method." IEEJ Transactions on Power and Energy 116, no. 5 (1996): 539–46. http://dx.doi.org/10.1541/ieejpes1990.116.5_539.
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He, Jian, and Xian Xin Li. "Application Analysis of Expanded Conductor in 1000kV UHV Double-Circuit Line." Applied Mechanics and Materials 664 (October 2014): 318–25. http://dx.doi.org/10.4028/www.scientific.net/amm.664.318.
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This paper discusses the feasibility and effectiveness of the application of expanded conduct in 1000kVultra high voltage AC (UHVAC) transmission line. Through the comparison and analysis between expanded conduct and conventional conduct in transmission capacity, mechanical properties, project investment, annual cost and other aspects, it shows that the initial investment of expanded conduct is 4% lower than that of conventional conduct; and the annual cost of expended conductor is superior to that of conventional conduct when transmission capacity, power price and use hours are low.
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Kolyshkin, A. A., and Rémi Vaillancourt. "Double conductor line above a two-layered cylinder with varying properties." Journal of the Australian Mathematical Society. Series B. Applied Mathematics 38, no. 1 (1996): 1–15. http://dx.doi.org/10.1017/s0334270000000436.
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AbstractThe change of impedance per unit length in a single or double conductor line situated parallel to an infinitely long two-layered metallic circular cylinder is found (within the quasistatic approximation) in the form of an infinite series. The cylinder consists of an inner core and an outer annulus. The properties of the inner core are assumed to be constant. The relative magnetic permeability, μ(r) = rα and the conductivity, σ(r) = σ(0)rκ, of the outer annulus vary with respect to the radial coordinate, r, and α and κ are arbitrary real numbers. Numerical results are presented in the form of figures and tables.
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Hrabovský, Juraj, Roman Gogola, Justín Murín, and Tibor Sedlár. "Modeling of Ice-Shedding from ACSR Power Line." Strojnícky casopis – Journal of Mechanical Engineering 67, no. 1 (2017): 45–54. http://dx.doi.org/10.1515/scjme-2017-0005.
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Abstract In this contribution, the analysis of ice-shedding from Aluminium Conductor Steel Reinforced (ACSR) power lines is presented. The impact of the icing position on the overhead power lines, the resulting jump height, and impact on attachment tension points after ice-shedding is examined. In the numerical simulations the effective material properties of the ACSR conductor is calculated using the homogenisation method. Numerical analysis of one power line and double-bundle power lines with icing over the whole range or only on certain sections of single and double-bundle power lines are performed
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Kim, Byung Geol, Su Dong Park, Shang Shu Kim, and Hee Woong Lee. "Strain Change and Creep Behavior of STACIR/AW Power Line with Heat Exposure." Materials Science Forum 475-479 (January 2005): 1751–54. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.1751.
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As a way to expand electric capacity in power line with hovering of electric power demand, STACIR/AW (super thermal-resistant Al alloy conductors Al-clad Invar-reinforced) overhead conductor which cans double ampacity has been developed. The STACIR/AW power line is mechanically composite stranded wire composed of INVAR/AW stranded wire as core for sag control and heat-resistant aluminum alloy for delivering doubled electric current. Recently, in order to ensure stable line operation and to predict its span of life, the changes of thermal properties for STACIR/AW have been investigated. In the present work, the changes of strain with temperature and the creep behavior as important factors in sag control will be presented. The transition temperature of STACIR/AW 410sqmm was estimated approximately 130°C and the creep rates were decreased with temperatures.
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Zhou, Ruqin, Wanshou Jiang, and San Jiang. "A Novel Method for High-Voltage Bundle Conductor Reconstruction from Airborne LiDAR Data." Remote Sensing 10, no. 12 (2018): 2051. http://dx.doi.org/10.3390/rs10122051.
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The security of high-voltage power transmission corridors is significantly vital to the national economy and daily life. With its rapid development, LiDAR (Light Detection and Ranging) technology has been widely applied in the inspection of transmission lines. As the basis of potential hazard detection, a robust and precise power line model is a necessary requirement for rapid and correct clearance. Thus, this paper proposes a novel method for high-voltage bundle conductor reconstruction, which can precisely reconstruct each sub-conductor. First, points in high-voltage power transmission corridors are detected and classified into four categories; second, for classified power lines, single power line spans are extracted, and bundle conductors are identified by analyzing the single spans’ fitting residuals; and then, each sub-conductor of bundle conductors is extracted by a projected dichotomy method on the XOY and XOZ planes, respectively; finally, a double-RANSAC (random sample consensus)-based algorithm was introduced to reconstruct each power line. The proposed method makes use of the distribution of bundle conductors in high-voltage transmission lines, and our experiments showed that it could preferably reconstruct the real structure of bundle conductors robustly with a high precision better than 0.2 m.
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Chen, Jian-Xin, Ching-Hong K. Chin, and Quan Xue. "Double-Sided Parallel-Strip Line With an Inserted Conductor Plane and Its Applications." IEEE Transactions on Microwave Theory and Techniques 55, no. 9 (2007): 1899–904. http://dx.doi.org/10.1109/tmtt.2007.904055.
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Mohammad Reza, Bahrami. "Mechanics of Electrical Transmission Line Robot Inspector: Pendulum as a Dynamic Vibration Absorber." E3S Web of Conferences 162 (2020): 03004. http://dx.doi.org/10.1051/e3sconf/202016203004.
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The purpose of this article is to design a new dynamic vibration absorber (DVA) and create a mathematical model to analyze the electrical transmission lines inspection robot movement on the line. First, the vibration of the electrical line while the robot inspector moves along it has been modeled considering the conductor as a stretched string and the robot as a moving load. It follows by using a double pendulum as the dynamic vibration absorber. To better understanding the performance of the DVA, the results are compared with the model in which a robot inspector is considered as a pendulum with a suspension base (here the conductor). This example shows the possibility of usage of the double pendulum as the DVA in electrical transmission inspection robots.
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Jitendra, G. Jamnani. "Power Transmission Capacity Enhancement of EHV AC Double Circuit Transmission lines by Increasing Surge Impedance Loading Level Considering Corona Loss Effect." European Journal of Advances in Engineering and Technology 5, no. 1 (2018): 55–60. https://doi.org/10.5281/zenodo.10701848.
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<strong>ABSTRACT </strong> Increase in the power demand requires the development of EHV AC double circuit and high power carrying capacity lines. Generally, the power generating stations are far away from the distribution network and to connect the power surplus region to power deficit region we need long EHV AC double circuit transmission lines to carry large amount of power. But the long EHV AC transmission lines are limited by their SIL (Surge Impedance Loading) limit which is much below the thermal limit of conductor due to large inductive reactance of the line. SIL depends on various factors and geometrical arrangement of double circuit transmission lines i.e. bundle spacing, diameter of conductor, no. of sub-conductors per phase, etc. In this paper an attempt is made to present various techniques implemented on EHV AC double circuit transmission lines to improve SIL level and also its effect on corona loss is shown with the help of mathematical programming in Matlab software. In this paper various double circuit configuration and its comparison is also presented.
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Berzan, V., V. Patiuc, and G. Rybacova. "Mathematical Model of Electrical Line with Transposition of Phase Circuits." Problemele Energeticii Regionale 2(37) (August 15, 2018): 1–12. https://doi.org/10.5281/zenodo.1343398.
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The purpose of this paper is to elaborate the mathematical model and the method of calculation of the permanent regime in the line with many conductors with transposed phases. The mathematical model is based on the telegraph equations and takes into account the fact that the electric lines are lines with distributed parameters. As a subject of the study it is selected the 110 kV overhead power line with two compact circuits with the conductors placed horizontally and circularly transposed. The initial and boundary conditions are formulated for the case of two-circuit electric line and the adjustment of the phase angle of the voltages at the line input. In the transposition the values of the conductor parameters change by leap, which complicates the process of calculating the operating mode. The developed model and elaborated software include all these features. Based on the developed model, calculations of the operating mode of the two-circuit electric circuit and of the selfcompensated line were performed. Numerical solutions have been obtained regarding the evolution of active and reactive power in the phases of the line in its various sections under regulation and nonregulation of the phase shift angle for the cases without and with the transposition of the phase conductors. The applicability of the model for studying power transfer processes in multi-conductor power lines has been demonstrated. There were obtained the numerical solutions useful for estimating the degree of mutual influence of phases on the ability to transfer power to load under the transposition of conductors.
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Rohit, Gupta, Gupta Rahul, and Verma Dinesh. "Analysis of Transmission Lines by Double Rohit Transform." SSRG International Journal of Recent Engineering Science 10, no. 3 (2023): 33–38. https://doi.org/10.14445/23497157/IJRES-V10I3P105.
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Abstract - The term transferral or transmission or transference line points to a specialized wire manufactured from copper or aluminum laid out with excellent dielectric or non-conductor and used for the transferral of electrical energy. Generally, a transferral line has a resistor put up by the two wires taken together, an inductor, a shunt conductance and a capacitor. The four quantities form the principal criterion of the transferral lines, and they turn on the class and assembly of transferral lines. Traditionally, the wave equations of transferral lines are examined by the Fourier transform or Laplace Transform. These transform procedures are very opportune for examining typical wave equations of electric transferral lines. The RT is the latest integral transform technique that has been tried to examine the boundary value differential equations standing up in separate engineering scopes. This paper disburses the solution of wave equations of transferral lines having negligible losses to earth or deck through dielectric by the double RT. The double RT will transpire to be a very positive tool for examining the wave equations of transferral lines.
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Jun, Ma, Shi Yonggang, Dong Gang, et al. "Spacer for Double Bundle in Phase Conductor of Transmission Line Based on Cross Universal Joint Structure." IOP Conference Series: Earth and Environmental Science 687, no. 1 (2021): 012117. http://dx.doi.org/10.1088/1755-1315/687/1/012117.
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Fache, N., and D. De Zutter. "Full-wave analysis of a perfectly conducting wire transmission line in a double layered conductor-backed medium." IEEE Transactions on Microwave Theory and Techniques 37, no. 3 (1989): 512–18. http://dx.doi.org/10.1109/22.21622.
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Yao, Lidan, Yongle Wu, Mingxing Li, and Yuanan Liu. "Three‐dimensional high‐isolated dual‐band balun using double‐sided parallel‐strip line with inserted conductor plane." Electronics Letters 53, no. 17 (2017): 1211–13. http://dx.doi.org/10.1049/el.2017.1954.
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Djekidel, Rabah, Ahmed Bessedik, and Abdechafik Hadjadj. "Electric field modeling and analysis of EHV power line using improved calculation method." Facta universitatis - series: Electronics and Energetics 31, no. 3 (2018): 425–45. http://dx.doi.org/10.2298/fuee1803425d.
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This paper aims is devoted to modeling and simulation of electric field created by EHV power transmission line of 275 kV using an efficient hybrid methodology, the charge simulation method (CSM) with the Simplex Simulated Annealing (SIMPSA) algorithm in order to find the optimal position and number of fictitious charges used in CSM for an accurate calculation. Various factors that affect the electric field intensity were analyzed; it is found that the influence of the conductor sagging is clearly remarked, the maximum electric field strength at 1 m above the ground level recorded at mid-span point of the power line is 3.09 kV/m, in the proximity of the pylon, the maximum value is significantly reduced to 1.28 kV/m. The configuration type of the transmission line (single or double circuit) and the arrangements of phase conductors on double circuit pylons have a significant effect on the levels of electric field around the transmission line. For a single circuit, the triangular configuration provides the lowest maximum value of electric field. For a double circuit, the inverse phase arrangement (abc-cba) or low-reactance phasing produces the lowest maximum value of electric field. The resulting maximum electric field levels were found below the exposure values set by the ICNIRP and IRPA standards for both occupational and general public. The simulation results of electric field are compared with those obtained from the COMSOL 4.3b Multiphysics software, a fairly good agreement is found.
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Makwana, Vijay H., and Bhavesh R. Bhalja. "A New Digital Distance Relaying Scheme for Series-Compensated Double-Circuit Line During Open Conductor and Ground Fault." IEEE Transactions on Power Delivery 27, no. 2 (2012): 910–17. http://dx.doi.org/10.1109/tpwrd.2011.2178438.
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GONZALEZ CAGIGAL, MIGUEL ANGEL, JOSE ANTONIO ROSENDO MACIAS, ALFONSO BACHILLER SOLER, LUCIA MATEO SANCHEZ, and ROBERTO ALVARO HERMANA. "DYNAMIC LINE RATING IN OVERHEAD TRANSMISSION LINES. MONITORING METHODS AND FIELD APPLICATION." DYNA DYNA-ACELERADO (December 19, 2022): [ 7 pp]. http://dx.doi.org/10.6036/10729.
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This paper presents different methods for overhead transmission line monitoring and the calculation of dynamic line rating. Some of these techniques are based on the reading or the prediction of the whole set of meteorological variables involved in the corresponding equations, whereas other methods use direct or indirect measurements of the conductor temperature. Additionally, a correction method will be described for incomplete monitoring situations. Finally, a real case study is presented for a 220-kV overhead line, where a double monitoring technique is considered for the calculation of the dynamic line rating, with a remarkable improvement in the utilization of the assets, compared to the seasonal rating. Keywords: Dynamic line rating, overhead transmission lines, grid operation and planning, electric power system monitoring.
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Daniel, Isaac H., Nicodemus Kure, Peter Anthony, and Phillibus M. Gyuk. "Stitched Transmission Line for Broadband Operations." Physics Access 03, no. 01 (2023): 22–27. http://dx.doi.org/10.47514/phyaccess.2023.3.1.004.
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Wearable stitched transmission lines made from stripped RG174 and textile materials are introduced for broadband operations. The stitched transmission lines which are 150 mm long consists of an inner conductor surrounded by a tubular insulating layer. For shielding purposes, the structures are stitched into a denim material with conductive threads. The performances of the stitched transmission lines with three different stitch patterns, Double Overlock, Flatlock stitch and Ric-Rac stitch were investigated and results obtained confirm that Ric-Rac stitched transmission line has fewer DC losses than the three stitched transmission lines for frequencies up to 1 𝐺𝐻𝑧. However, beyond that up to 2.4 𝐺𝐻𝑧 and above, it was observed that the Flatlock stitched transmission line and the Double Overlock stitched transmission line have fewer radiation losses compared to the Ric-Rac stitched transmission line. Similarly, the performance of the stitched transmission line when bent through curved angles of 90° and 180° was considered, and a much better 𝑆ଶଵ was observed with a curved angle of 180° for frequencies below 2.1 𝐺𝐻𝑧, with radiation loss increasing afterwards. Finally, the sensitivity of the design to manufacturing tolerances, with changes in cross-sectional dimensions of the stitched transmission line and the transmission characteristics with different textile substrates were both considered. While simulated results showed that the stitched transmission line is sensitive to small variations in its circular dimensions, measured results conversely showed that Denim and Felt materials can be used as a substrate without any significant effect on its propagation characteristics.
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Li, Tianchu, Zhipeng Wu, Yuanhuang Liu, Hongyan Liu, and Ming Fang. "Influence of phase sequence arrangement on the electromagnetic environment of four-circuit AC line on the same tower." Journal of Physics: Conference Series 2474, no. 1 (2023): 012048. http://dx.doi.org/10.1088/1742-6596/2474/1/012048.
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Abstract The paper predicts the power frequency electric field (PFEF), audible noise (AN), and radio interference (RI) of double-circuit 220kV and double-circuit 110kV four-circuit lines on the same tower erected on the same tower through the numerical calculation method of electromagnetic environment (EME) of AC transmission lines (TLs). Through a typical tower structure, the influence of the phase sequence (PS) on the EME is analysed, and the optimal and worst PSs are obtained. The optimal PS can significantly improve the EME, especially with a good confinement effect on the electric field’s power frequency. In addition, it also focuses on analyzing the influence degree of PS when the phase spacing, conductor-to-ground height and layer spacing change and establishes the applicable range of the optimal PS.
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Swetapadma, Aleena, and Anamika Yadav. "Fuzzy Inference System Approach for Locating Series, Shunt, and Simultaneous Series-Shunt Faults in Double Circuit Transmission Lines." Computational Intelligence and Neuroscience 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/620360.
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Many schemes are reported for shunt fault location estimation, but fault location estimation of series or open conductor faults has not been dealt with so far. The existing numerical relays only detect the open conductor (series) fault and give the indication of the faulty phase(s), but they are unable to locate the series fault. The repair crew needs to patrol the complete line to find the location of series fault. In this paper fuzzy based fault detection/classification and location schemes in time domain are proposed for both series faults, shunt faults, and simultaneous series and shunt faults. The fault simulation studies and fault location algorithm have been developed using Matlab/Simulink. Synchronized phasors of voltage and current signals of both the ends of the line have been used as input to the proposed fuzzy based fault location scheme. Percentage of error in location of series fault is within 1% and shunt fault is 5% for all the tested fault cases. Validation of percentage of error in location estimation is done using Chi square test with both 1% and 5% level of significance.
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Krotkov, Evgenij A., Nadezhda V. Bezmenova та Aleksandr A. Shchobak. "Accounting for wire saggingоn span of 220 kV OHL whendetermining current, induced in ground wire by phase current magnetic fields". Vestnik of Samara State Technical University. Technical Sciences Series 30, № 1 (2022): 106–17. http://dx.doi.org/10.14498/tech.2022.1.7.
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Overhead ground-wire cable (GW) is more prone to ice formation compared to 220 kV overhead lines. Ice-melting methods for GW using special power source have certain engineering constraints and required is connection of overhead line. Preventive heating of GW to above-zero temperature is an equivalent method to ice-melting. Preventive heating shall be provided by induction from electromagnetic field (EMF) of 220 kV overhead lines while in service. Induction methods of 220 kV OHL GW heating have been summarized and briefly described. Mathematical models of GW inductive heating do not consider the influence of wire and GW saggingon EMF parameters and equivalent circuit ground wire-earth. Therefore, sufficient mathematical model is required to use induction method of GW heating at 220 kV OHL segment. We propose induction heating for GW of double-circuit 220 kV OHL inclosed circuit ground wire-additional conductor top reventice formation. Mathematical model have been developed to calculate current, induced in circuit ground wire-additional conductor by magnetic fields of 220 kV OHL current while in service. Influence of wire and GW saggingon EMF parameters and equivalent circuit ground wire-additional conductor has been estimated. Due to mathematical model we could estimate induced current to prevent ice formation on GW of double-circuit 220 kV OHL while in service. Closed circuit ground wire-additional conductor is recommended for practical use, with capacitor loop included into circuit, its capacitance to be determined based on voltage resonance conditions.
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Huang, Wen, Wei Ruan, and Fei Tan. "A Miniaturized 4 : 1 Unequal Wilkinson Power Divider Using Artificial Transmission Lines and Double-Sided Parallel-Strip Lines." International Journal of Antennas and Propagation 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/6751694.
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A 4 : 1 unequal Wilkinson power divider using microstrip artificial transmission lines (ATLs) is proposed. For the ATL, a series of meandered-line inductors, parallel-plate capacitors, and interdigital capacitors are employed. The designed power divider is composed of three ATLs, and a method has been proposed using technology of ATLs and double-sided parallel-strip lines (DSPSLs) to design line of high characteristic impedance. Microstrip line with very high characteristic impedance of over 150 Ω has been achieved by this method, which cannot be easily achieved by conventional transmission lines because of comparably thin conductor width. The fabricated 4 : 1 unequal power divider has good operational performance and occupies55.3 mm×37.8 mm, which is only about 40% of area compared to a conventional one at 0.9 GHz.
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Liu, Lei, Minchuan Liao, Lei Jia, Bin Li, and Wenxin Wan. "The Calculation Method of the Floating Conductor Potential in the Ion Flow Field." Journal of Physics: Conference Series 2656, no. 1 (2023): 012013. http://dx.doi.org/10.1088/1742-6596/2656/1/012013.
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Abstract For bipolar DC transmission projects, when one pole conductor is charged and running normally, and the other pole conductor is in a standby state (including cold standby and hot standby), if the standby pole conductor is not grounded, a high charging potential will appear on the surface. On the one hand, it will affect the insulation coordination and protection setting of the DC system. On the other hand, it will also affect the ion current and synthetic electric field on the ground. This article studies the calculation method of the potential of suspended conductors in the presence of floating conductors in the ion flow field, establishes a calculation model based on the minimum absolute value of the space charge density on the surface of the conductor, and calculates and analyzes the distribution of ionizing current and synthetic electric field below the ground of high-voltage DC lines in the presence of suspended conductors. The distribution laws of ground field strength and ion current in single-circuit bipolar DC transmission lines are studied when one pole is suspended, the other is operated, and when one circuit is operated. One circuit is shut down in double-circuit DC transmission lines on the same tower. For practical engineering, on the one hand, it is possible to predict the potential of suspended conductors in the ion flow field and propose adjustment plans for protection settings, insulation coordination, etc., in advance. On the other hand, when considering abnormal operating conditions, the impact of ion flow fields on the ground electromagnetic environment can be reduced by changing the geometric architecture and line selection.
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An, Guan, Zhu, and Zhang. "Research on Windage Yaw Flashovers of Transmission Lines under Wind and Rain Conditions." Energies 12, no. 19 (2019): 3728. http://dx.doi.org/10.3390/en12193728.
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Windage yaw flashovers under strong wind and rain conditions leave a negative impact on the safe operation of transmission lines. However, the mechanism behind this is not well known yet. Therefore, this paper proposes a systematic method, including three basic parts described as simulation of wind and rain loads, calculation of windage yaw, and flashover analysis, to analyze windage yaw flashovers of transmission lines. The YanMeng-particle swarm optimization (YanMeng-PSO) algorithm is proposed to enhance the simulation accuracy. Unlike the conventional approach, the windage yaw status of conductors and insulator strings is dynamically described with key nodes and the breakdown voltage of their clearances rather than windage yaw angle. Furthermore, in the second part, a new method named key-node method (KNM) is proposed to calculate the conductors’ windage yaw. Moreover, the rain effect is also considered in this paper. This paper then presents a case study on a 110 kV double-circuit transmission line section that suffered severe collapse when the typhoon Rammasun landed in Hainan island. Particular focus was placed on the windage yaw flashover before the structural failure of the transmission line. The results validated the significant rain effect and found that conductors/ground suffer more severe windage yaw flashover than insulator strings. Finally, constructive solutions such as interphase spacers, reasonable conductor arrangement in the design phase, and regular measurements and adjustments of conductor sag in the maintenance phase are proposed to improve the design of transmission lines to enhance their capacity against windage yaw flashovers.
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Bouhassoune, Ibtissame, Rachid Saadane, and Khalid Minaoui. "RFID Double-Loop Tags with Novel Meandering Lines Design for Health Monitoring Application." International Journal of Antennas and Propagation 2019 (October 1, 2019): 1–12. http://dx.doi.org/10.1155/2019/5076139.
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In this paper, we propose a design of two compact and miniaturized RFID epidermal tags in the UHF band for health monitoring applications. The two conceptions of meandered double-loop antennas with T-match configuration, namely, a double-loop antenna with meandered line in the horizontal direction and a double-loop antenna with meandered lines in two directions, are placed at very close distance from the human body. The proposed tags are composed of bio-silicone substrate, to protect the human skin from the electromagnetic waves, and a copper conductor loaded by T-match configuration, to suit the complex impedance of the antenna to that of the chip. We have performed numerical simulations of these conceptions of two tags using the HFSS and CST solvers. Our results show two optimal sizes with a high communication performance, good matching features, and a large read range. We placed afterwards these two optimized tags in an elliptical environment to test their flexibility and examine their performance on different parts of the human body.
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Tomislav Barić, Zijad Haznadar, and Sead Berberović. "PARAMETERS AFFECTING THE TRANSIENT RESPONSE OF VERTICAL PIPE ELECTRODES TO IMPULSE EXCITATION." Journal of Energy - Energija 57, no. 2 (2022): 226–45. http://dx.doi.org/10.37798/2008572323.
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In this article, an application of the transmission line theory is presented for analyzing various parameters that affect the transient response of ground electrodes. In order to simplify the presentation and the interpretation of the results obtained, a vertical buried pipe electrode was chosen as the ground electrode. The ground electrode is connected to a grounding conductor, the upper part of which is connected to an ideal current source. The impact of the overhead geometry of the grounding conductor upon the transient response of the ground electrode is analyzed by varying the length of the grounding conductor. The ideal current source generates a normalized wave shape current impulse, a so-called double exponential impulse. The effect of the time to peak of the impulse (steepness of the rising edge of the peak current) on the transient response of the ground electrode is analyzed by varying the current wave shape parameters. The impact of soil parameters on the transient response of the ground electrode is also analyzed. The soil is modeled as a single-layer homogeneous isotropic semispace. The soil-air boundary is represented by a plane. The results obtained are presented graphically and discussed.
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Liu, Yunjia. "Analysis and Research on Power Supply Strategies of Electric Vehicles Based on Wind Farms." World Electric Vehicle Journal 13, no. 2 (2022): 38. http://dx.doi.org/10.3390/wevj13020038.
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The widespread growth of electric vehicles could pose significant grid and charging infrastructure challenges, especially in areas with underdeveloped infrastructure. This has affected the ease of charging electric vehicles. In this paper, I design a power supply strategy for electric vehicle charging facilities based on wind farm power supply. In this strategy, a preliminary selection of line conductors is carried out, and several schemes are preliminarily determined. Further comparative analysis is made from the three aspects of conductor, tower type, and bus. Through the PowerWorld software, a simulation model is established for each scheme, and an optimal strategy that takes into account economy, security, and system stability is obtained (AAC 31.5 mm double split, tower A and bus 5). This can assist in the transformation of electric vehicle power supply and the construction of wind farm power supply facilities.
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Li, Lu, Wei-Zheng Zhang, Jia-Tao Zhang, Xin Qu, Qi Peng, and Run-Ge Hu. "Study on the Propagation Characteristics of Partial Discharge Electromagnetic Waves in Gas Insulated Line." Journal of Nanoelectronics and Optoelectronics 16, no. 8 (2021): 1317–24. http://dx.doi.org/10.1166/jno.2021.3074.
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Defects in the gas insulated line can cause partial discharge, and the electromagnetic wave is generated. The finite difference time domain method is used to research the propagation of electromagnetic wave in gas insulated line structures. The electric field strength of time-domain waveform is selected as characteristic factor for analysis. By changing the gas insulated line model, the attenuation of electromagnetic wave through double insulator, L-type corner, T-type corner, straight tube and different GIL sizes is studied. In the straight tube structure, the amplitude attenuation of electromagnetic wave is linear and the attenuation band is between 1 GHz and 1.7 GHz. In the insulator, basin insulator has more serious influence on signal isolation than disc insulator. After passing through the insulator, the signal attenuation is obvious in the frequency band above 1 GHz. The amplitude of electromagnetic wave decreases more seriously through the corner structure, and the attenuation is at the whole frequency band. In different sizes of gas insulated line, the larger diameters of shell and conductor, the larger electromagnetic wave will be, and the faster attenuation will be; the length of gas insulated line cavity has little effect on electromagnetic wave. The theoretical research is expected to help to arrange the position of ultra-high frequency sensor reasonably.
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Xingdong, Bai, Du Minsheng, Zhou Zhangpeng, Liu Feng, Lv Qiang, and Zhang Yongxin. "Simulation Analysis of Electric Field on the Body Surface of Personnel Engaged in Interphase Live Working on 750 kV Double Circuit Transmission Lines on the Same Tower." Journal of Physics: Conference Series 2704, no. 1 (2024): 012008. http://dx.doi.org/10.1088/1742-6596/2704/1/012008.
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Abstract This article focuses on the assistance of electric lifting devices for phase-to-phase live working. Taking a typical 750 kV double circuit vertical arrangement line on the same tower as the research object, a three-dimensional simulation model of a real tower conductor simulated human is established. The field strength on the human body surface is calculated and analyzed during the process of operators entering the equipotential (conductor) while riding the electric lifting device in order to determine the risk points of the operation and determine the safety protection measures for the human body. Through simulation, it is found that when simulating human entry (exit) and phase-down operations, the human body is located at different distances of 0.4 m-1.5 m directly below the conductor. When not wearing shielding clothing, the maximum field strength of the human head is much greater than the allowable value. If using shielding clothing with a shielding efficiency of 60 dB for safety protection, the surface field strength inside the worker’s clothing can be reduced to 2.25 kV/m, meeting the requirements of live working. Operators should pay attention to the electric field protection at each phase wire when using an electric lifting device to enter (exit) the interphase wire. Equipotential operators must wear a complete set of shielding clothing for 750 kV live working.
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Rostov, Vladislav V., Alexei S. Stepchenko, Pavel V. Vykhodtsev, and Ruslan V. Tsygankov. "High-Voltage Drivers Based on Forming Lines with Extended Quasi-Rectangular Pulses for High-Power Microwave Oscillators." Electronics 11, no. 3 (2022): 406. http://dx.doi.org/10.3390/electronics11030406.
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The paper considers such modifications of an ordinary pulse-forming line (PFL) as double-width and triple-width forming lines (DWFL, TWFL) built around the PFL by nesting one and two additional uncharged lines, respectively, into its free volume inside the inner conductor of the PFL. The theoretical analysis is supported by simulation and experimental data, showing that the TWFL provides a 3-fold increase in the voltage pulse width and that it can be further increased by an arbitrary integer factor k. The results of the numerical simulations also show the electric field behavior and other features, including the edge effect in the TWFL. The proposed method opens up new opportunities for designing compact high-power microwace (HPM) sources.
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Alameri, Ban M. "ELECTROMAGNETIC INTERFERENCE (EMI) PRODUCED BY HIGH VOLTAGE TRANSMISSION LINES." EUREKA: Physics and Engineering 5 (September 30, 2020): 43–50. http://dx.doi.org/10.21303/2461-4262.2020.001398.
Full textAbstract:
Electromagnetic interference in high voltage transmission lines has been an interest topic due to its effect on human health, plants, electrical and telecommunication equipment. Extremely high voltages (EHV) in transmission lines are reasons of electrostatic effects, while short circuit currents and line loading currents are responsible for electromagnetic effects. The aim of this research is to analyze electromagnetic fields in high voltage transmission lines in theoretical study and calculating its level in overhead T. L and therefore estimated the EMI produced, by employing a mathematical model of 230 KV tower double circuit configurations of high voltage transmission lines. The calculation is based on computer aided analysis (CAA) by using fields and corona effects software (FACE). It's found that the overhead power lines of general frequency (50 Hz) generates a highly intense magnetic field, the electromagnetic fields depends on the distance from sources and the type of line configuration. They decrease as the distance increase from the tower and conductors and increase with a high current. The strength of an electric field is proportional to the voltage of the line and the magnetic field strength is proportional to the current in the high voltage transmission lines. Distribution line with a high current load may produce a magnetic field that is as high as those produced by some high voltage transmission lines. Some techniques of reduction of the effects of electromagnetic interference have suggested such as rearrangement conductors of transmission line, and distance from phase conductor and grounding system. The study recommended to keep safety distance operation in high voltage transmission lines with the necessity for engineer to take into account the effect of electromagnetic interference in the design stage of high voltage transmission power system, and to avoid any addition cost may be occur due to neglected effects of electromagnetic interference that produces by high voltage transmission lines
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Lee, Eui Su, and Han-Cheol Ryu. "Resonance Control of VO2 Thin-Film-Based THz Double-Split Rectangular Metamaterial According to Aspect Ratio." Photonics 9, no. 12 (2022): 966. http://dx.doi.org/10.3390/photonics9120966.
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The resonance characteristics of a double-split rectangular metamaterial based on a vanadium dioxide (VO2) thin film were controlled according to the aspect ratio of the rectangle in the terahertz (THz) frequency region. The VO2 thin film line was etched between the double-split rectangular gaps so that the resonance band could be switched by varying the characteristics of the VO2 thin film. When the VO2 thin film is in an insulator state, the rectangle is separated and resonates individually; thus, it resonates in the high-frequency band. When the VO2 thin film changes from an insulator to a conductor with a change in the temperature, the divided rectangles are electrically connected to operate as a single resonator, and the resonant frequency shifts to a low-frequency band. Varying the aspect ratio of the rectangle changes the resonant frequency and resonance strength of the double-split rectangular metamaterial. If the aspect ratio is increased by fixing the width of the unit cell of the metamaterial and adjusting the height, the resonant frequency is lowered in all situations, regardless of the state of the VO2 thin film and the polarization of the incident THz wave. The resonant frequency and resonance strength of the double-split rectangular metamaterial proposed in this paper could be controlled stably through a change in only the aspect ratio, not the overall unit cell size. The proposed double-split rectangular metamaterial based on an etched VO2 thin film is expected to be essential for THz tag, sensing, and wireless communication applications.
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Bora, Pankaj, Utpaljyoti Mahanta, Jayanta Kumar Sarmah, and Jyoti Prasad Gogoi. "Estimation of Microwave Absorption Properties of RGO-SiC-LLDPE Composites." Advanced Materials Research 1165 (July 23, 2021): 87–97. http://dx.doi.org/10.4028/www.scientific.net/amr.1165.87.
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The present work investigate the microwave absorption properties of reduced graphene oxide (RGO)-Silicon carbide (SiC)-Linear low-density polyethylene (LLDPE) composites prepared in different concentration of fillers(10, 20, 30, 40 wt. %) with LLDPE matrix. Synthesis of RGO is confirmed from XRD analysis and SiC is used as received from supplier. Complex permittivity of the composites is measured using Nicolson Ross method showing an increasing trend with increasing filler concentrations with maximum and for 40 wt. % composite sample. Based on transmission line theory and using measured value of complex permittivity, conductor backed single and double layer absorber is designed by thickness optimization. The calculated reflection loss (RLc) value of ~-71 dB at 11.23 GHz is observed for 40 wt. % composite sample of 7 mm thickness with -10 dB absorption bandwidth of 1.48 GHz and -20 dB bandwidth of 0.64 GHz.
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Ban, M. Alameri. "ELECTROMAGNETIC INTERFERENCE (EMI) PRODUCED BY HIGH VOLTAGE TRANSMISSION LINES." EUREKA: Physics and Engineering, no. 5 (September 30, 2020): 43–50. https://doi.org/10.21303/2461-4262.2020.001398.
Full textAbstract:
Electromagnetic interference in high voltage transmission lines has been an interest topic due to its effect on human health, plants, electrical and telecommunication equipment. Extremely high voltages (EHV) in transmission lines are reasons of electrostatic effects, while short circuit currents and line loading currents are responsible for electromagnetic effects. The aim of this research is to analyze electromagnetic fields in high voltage transmission lines in theoretical study and calculating its level in overhead T. L and therefore estimated the EMI produced, by employing a mathematical model of 230 KV tower double circuit configurations of high voltage transmission lines. The calculation is based on computer aided analysis (CAA) by using fields and corona effects software (FACE). It's found that the overhead power lines of general frequency (50 Hz) generates a highly intense magnetic field, the electromagnetic fields depends on the distance from sources and the type of line configuration. They decrease as the distance increase from the tower and conductors and increase with a high current. The strength of an electric field is proportional to the voltage of the line and the magnetic field strength is proportional to the current in the high voltage transmission lines. Distribution line with a high current load may produce a magnetic field that is as high as those produced by some high voltage transmission lines. Some techniques of reduction of the effects of electromagnetic interference have suggested such as rearrangement conductors of transmission line, and distance from phase conductor and grounding system. The study recommended to keep safety distance operation in high voltage transmission lines with the necessity for engineer to take into account the effect of electromagnetic interference in the design stage of high voltage transmission power system, and to avoid any addition cost may be occur due to neglected effects of electromagnetic interference that produces by high voltage transmission lines
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Hou, Sizu, and Xiaoyi Guo. "Research on Fault Location of Distribution Lines Based on the Standing Wave Principle." Processes 9, no. 8 (2021): 1436. http://dx.doi.org/10.3390/pr9081436.
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Aiming at the fast and accurate location of a single-phase ground fault in the distribution network, a single terminal injection signal location method, based on the standing wave principle, is proposed. Firstly, the double conductor standing wave principle formation, based on uniform transmission line theory, is analyzed, and the mathematical model of the fault distance algorithm is established. Secondly, a fault detection circuit is built by simulation, and the distribution trend of the standing wave and its relationship with unit capacitance and unit inductance are studied. By setting the source signal frequency and detection point interval and other parameters, the fault location of this method under direct grounding fault and through grounding resistance fault is simulated and studied. Finally, the fault distance is calculated and located by an experiment. The results show that the positioning accuracy is high, which verifies the effectiveness of the standing wave positioning method.
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Purwantono, Purwantono, Bahrul Amin, Abdul Aziz, Jasman Jasman, and Andre Kurniawan. "Performance test of Pikohidro Cross flow Water Turbine using multilevel double penstock." Teknomekanik 2, no. 2 (2019): 76–80. http://dx.doi.org/10.24036/tm.v2i2.4172.
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This study aims to examine the performance of pico hydro scale cross flow water turbines using multilevel double penstock as a conductor of water flow. Multilevel double penstock is used to reduce the transportation process from highways that are affordable to four-wheeled vehicles / cars to the location of the installation of the turbine. This condition causes the need for small-scale water turbine designs with lightweight construction with a kock down system. Overall the picohidro scale turbine construction is needed relatively cheaper transportation costs, so that people who have not been reached by the PLN network can be touched by small and cheap electricity. Turbine construction data has a runner diameter of 170 mm, body dimensions 200 mm x 300 mm x 250 mm, frame 250 mm x 800 mm. Pool tando 600 mm x 1200 mm and penstock length 16m. The power produced is theoretically around 2500 watts, with a data flow of 50 liters / second and a water level of 8 m. 65% efficiency. The research method is analyzing the double penstock water flow, by making paralon pipes in stages, ranging from 5 incci diameter, 4 inches and 3 inches, flow analysis approach using a gradient line, where the incoming water velocity and water velocity come out until entering the transmitting pipe. The performance results of this turbine provide an average actual power of up to 2000 watts. The stability of the inlet water condition is used by the Tando pond as a water bath. If there is excess water in the sediment tank, the water gate is used out, where excess water will automatically flow into the exhaust channel.
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Ruwah Joto, Dhimas Dhesah Kharisma, Mochammad Mieftah, and Aly Imron. "Optimalisasi Konfigurasi Fasa Vertikal Pada Saluran Udara Tegangan Ekstra Tinggi." Elposys: Jurnal Sistem Kelistrikan 12, no. 1 (2025): 43–48. https://doi.org/10.33795/elposys.v12i1.6848.
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The dangers arising from the 500 kV extra high voltage overhead lines to the surrounding environment can actually be minimized in several ways. One of the methods is to change the configuration of the conductor arrangement. Based on the laws in field theory which state that the magnitude of the field quantity on a charged conductor can differ depending on the distance, area, or volume, an analysis was carried out to understand the effect of the phase arrangement on the electric field intensity under the 500 kV overhead transmission line. The Finite Difference Method uses a numerical approximation to the partial derivative of the differential equation describing the electric field. The use of the Hybrid Tower combines vertical and horizontal designs to achieve a balance between low electric fields and land efficiency. Of the 36 combinations of phase arrangements on transmission lines with a double-circuit vertical configuration, there is a large variation in the resulting field intensity. Information on the phase arrangement that produces the smallest field intensity is very important. The arrangement of 36 (arrangement T1-S1-R1: T2-S2-R2) produces the lowest electric field intensity. Compared with the super bundle arrangement (arrangement R1-S1-T1: R2-S2-T2), there is a decrease in field intensity of up to 45.842%, while compared with the low reactance arrangement (arrangement R1-S1-T1: T2-S2-R2), there is a decrease in field intensity of up to 33.374%.
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Hussein, Khalid F. A. "Optimized Wideband Impedance Matching Balun for Conducting Two-Arm Antennas." International Journal of Antennas and Propagation 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/748216.
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A split coaxial balun with a step transition of the inner conductor diameter is introduced to satisfy impedance matching between unbalanced feeder and balanced antennas. The location of the step transition along the axis of the balun and the diameter change are two dimensional parameters that are not present in the conventional split coaxial balun. These additional parameters, together with the double slot width, provide more flexibility to design the balun for better impedance matching. The effects of the three dimensional parameters on the input impedance seen at the (unbalanced) coaxial line side of the balun are investigated when it is terminated with specific lumped impedance at its (balanced) split side. An optimization procedure is introduced to arrive at the balun dimensional parameters to give the best matching with specific load impedance. The proposed balun is designed to feed (balanced) two-arm antennas such as the dipole and the bowtie antenna from 50 Ω-coaxial line. The electromagnetic simulation shows that the proposed balun results in a perfect impedance matching. A comparison with the performance of the conventional split balun used to feed a dipole antenna shows that the balun proposed in the present paper gives a much lower value of the return loss at the design frequency and a wider bandwidth for VSWR ≤ 1.5. The simulation results obtained using the MoM are compared with experimental measurements showing good agreement.
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Trotsenko, Yevgeniy, Artem Nesterko, and Mandar Dixit. "ANALYSIS OF APPROACHES FOR ESTIMATING THE LIGHTNING PERFORMANCE OF OVERHEAD TRANSMISSION LINES." Transactions of Kremenchuk Mykhailo Ostrohradskyi National University, no. 6(131) (December 26, 2021): 116–21. http://dx.doi.org/10.30929/1995-0519.2021.6.116-121.
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Purpose. A review of the current literature, regarding the existing approaches used to estimate the lightning perfor-mance of overhead power lines, was performed. A review of available lightning activity data over India was also per-formed. Methodology. The electro-geometrical model was chosen to analyze the lightning performance of overhead power lines. International normative documents and national standard were used to highlight the main parameters that should to be paid main attention to when estimating lightning performance of overhead power lines. Results. Presently, approaches from IEEE and CIGRE guides can be used for analysis of statistical distributions of lightning current pa-rameters. Further studies are required on thunderstorm days, ground flash density and current parameters statistical dis-tributions for different locations, which will be supportive in performing analysis for Indian power lines. Originality. To graphically analyze the shielding failure mechanism with a help of electro-geometric model, the sketch of real 220 kV double-circuit transmission line tower was used. Using electro-geometric model it was graphically shown how downward lightning leader that propagate from thunderstorm cloud toward ground can finish its path on the overhead shield wire, phase conductor or ground plane. Practical value. Available data on lightning activity over different parts of India are still not enough complete. It is of great importance to obtain reliable statistical data on thunderstorm characteristics in the area of the studied power line route. Measurement techniques based on satellites have limitations in obtaining ground flash density values. Thus, for India there is a need in development of modern lightning detection networks and related studies on lightning characteristics. Conclusions. Future efforts should be focused on obtaining not only the positions and number of lightning strikes to the overhead power line, and calculation of lightning flashover rate parameters, but also the statistical distributions of lightning current values and related overvoltage parameters at the overhead wires and different phase conductors. References 21, figures 4.
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Basharkin, Maksim. "Dependence of rail potential on the resistance of the traction substation grounding device and rail line parameters." Bulletin of scientific research results 2024, no. 3 (2024): 24–33. http://dx.doi.org/10.20295/2223-9987-2024-03-24-33.
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Purpose: to analyse the dependence of the potential on rails on the track coordinate at different values of conductivity of the grounding device of the traction substation (g0 = 0 S, 10 S, 25 S, 50 S). Methods: the analysis was carried out on the developed substitution diagram of the traction rail network section using the method of nodal potentials. The calculation was implemented in Mathcad 15 mathematical package. Selection of initial data was carried out taking into account the values established in the current normative documentation. Results: an equivalent substitution scheme of the traction rail network on a double-track section has been developed, in which each homogeneous section of the rail line is replaced by an equivalent U-shaped quadrupole. This allows to transform an electric circuit with distributed parameters into a circuit with concentrated parameters. If it is necessary to simulate transverse or longitudinal asymmetry of traction current in a section, such a section is replaced by a three-wire substitution diagram in which the earth conductor is taken into account. To improve the accuracy of the modelling results, the inter-track jumpers are taken into account, and the number of nodal potentials is increased to 7. It is established that the highest modulus value of voltage on rails is observed near the traction substation. It has been determined that the voltage value on rails near the traction substation decreases when the conductivity of the earthing device increases. Practical significance: values of rail-ground potential at different values of conductivity of grounding device of traction substation for tracks of both directions of traffic — even and odd tracks — are determined. The value of conductivity of the traction substation grounding device at which it is safe for the personnel to stay on the rails near the traction substation has been determined. The obtained results can be recommended for practical use in railway transport.
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Mendes Da Silva, Rita, Anita Zeidler, Henrik Bradtmüller, et al. "Structure of amorphous materials in the NASICON system Na 1+x Ti2Si x P 3−x O12." Journal of Physics: Condensed Matter 35, no. 27 (2023): 274002. http://dx.doi.org/10.1088/1361-648x/acc8af.
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Abstract The structure of glasses in the sodium (Na) super-ionic conductor (NASICON) system Na 1 + x Ti2Si x P 3 − x O12 with x = 0.8 and x = 1.0 was explored by combining neutron and high-energy x-ray diffraction with 29Si, 31P and 23Na solid-state nuclear magnetic resonance (NMR) spectroscopy. The 29Si magic angle spinning (MAS) NMR spectra reveal that the silica component remains fully polymerized in the form of Si4 units, i.e. the silicon atoms are bound to four bridging oxygen atoms. The 31P{23Na} rotational echo adiabatic passage double resonance (REAPDOR) NMR data suggest that the 31P MAS NMR line shape originates from four-coordinated P n units, where n = 1, 2 or 3 is the number of bridging oxygen atoms per phosphorus atom. These sites differ in their 31P-23Na dipolar coupling strengths. The results support an intermediate range order scenario of a phosphosilicate mixed network-former glass in which the phosphate groups selectively attract the Na+ modifier ions. Titanium takes a sub-octahedral coordination environment with a mean Ti–O coordination number of 5.17(4) for x = 0.8 and 4.86(4) for x = 1.0. A mismatch between the P–O and Si–O bond lengths of 8% is likely to inhibit the incorporation of silicon into the phosphorus sites of the NASICON crystal structure.
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Thai, Nguyen, and Dong Doan Van. "A Research on Passenger Carrying Capacity of an Innovative Electric Traction Power Supply System based on ROCS of 750 V DC MRT." Engineering, Technology & Applied Science Research 14, no. 4 (2024): 15033–38. http://dx.doi.org/10.48084/etasr.7625.
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This article presents the results of a study on the feasibility of a Rigid Overhead Conductor-rail System (ROCS) for a Mass Rapid Transit (MRT) system using 750 V DC power based on a carrying capacity transport-supply voltage level relationship. In particular, peak load conditions often cause serious problems of voltage drops occurring along the contact line, affecting the reliability, flexibility, system safety, and efficiency performance of the MRT system. The potential at the pantograph of a train on the segment of power supply depends significantly on the structure of the traction power supply network, contact network type, and voltage level. Recently, there have been studies on the dynamics of ROCSs under the impact of train motion, thereby applying the design to several railway systems in the world in specific conditions such as tunnels, stations, or viaducts. To consolidate the advantages of this trend, this paper studies the operating voltage of an ROCS in a full-line MRT system with a voltage level of 750 V DC belonging to the third rail. Matlab R2017b/Railway Systems is a reliable software for simulating and analyzing the necessary data. The results exhibit the feasibility of the designed ROCS. The system has a passenger carrying capacity of up to 90,000 passengers per hour per direction (p/h/d) under both normal and fault conditions. In this case, this capacity is achieved with a single-end feed at a distance of 2 km from a Traction Power Station (TPS), with the minimum feeder voltage at the pantograph point being 532.7200 V. The lowest operational feeder voltage of the system is 523.6667 V, supplied from a double-end feed at a distance of up to 5 km from the TPS.
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Qin, Qiuliang, Shaoning Zhang, Chendong Zhao, et al. "Octopus-like carbon nanomaterial for double high stretchable conductor." Carbon 199 (October 2022): 200–207. http://dx.doi.org/10.1016/j.carbon.2022.08.023.
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Dong Il Lee, Jeong Boo Kim, Koo Yong Shin, Kwang Ho Yang, Hee Sung Ahan, and Ja Yoon Koo. "Audible noise performance of 6-rail conductors on a 765-kV double circuit test line." IEEE Transactions on Power Delivery 12, no. 3 (1997): 1343–51. http://dx.doi.org/10.1109/61.637013.
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Hao, Shu Ying, Kun Tao Zhou, Zhi Gang Chen, and Qi Chang Zhang. "Finite Element Analysis on Dynamic Tension of Quad-Bundle Conductor of Transmission Line Galloping." Applied Mechanics and Materials 48-49 (February 2011): 523–26. http://dx.doi.org/10.4028/www.scientific.net/amm.48-49.523.
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For profoundly understanding the influence of wind speed on the dynamic tension of iced bundle conductor, the influence of wind speed on galloping rules, tension variation, and amplitude of quad-bundle conductor under number 4-8 wind were investigated by nonlinear finite element analysis and theoretical analysis methods. The results shows that wind speed have great influence on galloping amplitude and dynamic tension. Galloping amplitude will rapidly increase with the increase of the wind speed at the beginning, but when the wind speed increased to a certain extent, the increase of galloping amplitude in plane and dynamic tension will become not obviously, and the maximum dynamic tension approximately doubles the static tension. The galloping and tension variation rules of bundle conductor were changed from stability periodic motion to complicated quasi periodic motion.
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Landini, Marco, Giovanni Mazzanti, and Riccardo Mandrioli. "Procedure for Verifying Population Exposure Limits to the Magnetic Field from Double-Circuit Overhead Power Lines." Electricity 2, no. 3 (2021): 342–58. http://dx.doi.org/10.3390/electricity2030021.
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The verification of the limits of the population’s exposure to the magnetic field generated by double-circuit power lines from field measurements carried out on site is not trivial. It requires knowledge of the power line current instant values during the measurement period, the determination of the relationship between current and field at the measurement points (made more complex by the double-circuit overhead line configuration) and the use of that relationship to extrapolate the field values. Nevertheless, the verification of exposure limits for double-circuit power lines from on-site measurements is often conducted with rough, or not particularly stringent, procedures. A practical and straightforward procedure of general validity for non-optimized double-circuit lines is proposed here. No specific measurement position or conductors disposition knowledge is required as well as no complex three-dimensional finite element method code is necessary. The procedure, potentially also applicable to high- and extra-high-voltage lines, is validated on a medium-voltage (15 kV) double-circuit overhead power line study case. Exposure limits assessment suggests that if the line is operated at its rated capacity (230/285 A), the 3 μT quality target is missed. Results are provided with a 95% confidence interval ranging from ±100 nT to ±140 nT in all the cases.
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Agati, Jean-Louis, Sébastien Caille, André Debackère, et al. "Activities and Achievements of the Double Star Committee of the Société Astronomique de France." Proceedings of the International Astronomical Union 2, S240 (2006): 509–26. http://dx.doi.org/10.1017/s174392130700645x.
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In a synthesis article (see ref. below), the double star expert Paul COUTEAU put the work of French pioneers of double stars observation in the perspective of the double star work carried in the world. After Antoine Yvon VILLARCEAU and Camille FLAMMARION, one prominent pioneer of double stars was Robert JONCKHEERE (1888–1974), an amateur before circumstances prompted him to become a professional astronomer, who devoted his life to double stars. Kenneth Glyn Jones wrote a biography and Charles Fehrenbach his obituary. Jean-Claude Thorel studied his life and career in double star observations (see Section 10 below). In the 1930s, another precursor of the Commission des Étoiles Doubles, Maurice DURUY (1894–1984) invented the micrometer with a comparison star, and applied the diffraction micrometer invented by Ejnar Hertzsprung to the measure of double stars, which he regularly observed at Nancy with a 275-mm telescope, at Lyon with a 162-mm telescope and in his observatory of Beaume-Mêle with a 40-cm and later a 60-cm telescope at Le Rouret (Alpes–Maritimes). He measured standard pairs of the list of Paul Muller and published his measures in the Journal des Observateurs; these measures requested by Paul Muller aimed at comparisons of between observers. He also collaborated with the Webb Society of Great Britain; Glyn Jones published his astronomical biography. Already in 1924, the pediatrician Paul BAIZE (1901–1995) had started the measurement of double stars as an amateur. He was granted permission to measure them with the 38-cm of the Paris Observatory and made an impressive number of measures during his long “career" (24044). He also made orbit calculations and established a formula for the calculation of dynamic parallaxes in 1946. He wrote articles explaining new observation techniques devoted to double stars in the magazine L'Astronomie and continued his astronomical activity until the beginning of the 1990s. Glyn Jones published an astronomical biography of Paul Baize. In the 1960s, Bernard CLOUET and the late Robert SAGOT (1910–2006) made double star observations for the book which was then in preparation under the title La revue des constellations. Their measures remained unpublished; but publication of the measures made by Robert SAGOT is in preparation. At about the same time, the neurology professor Jacques LE BEAU (1908–1998) made the acquaintance of renowned professional astronomer Paul COUTEAU and learned from him how to measure double stars. Each year, he stayed for two weeks at Nice and conducted his observations with the 50-cm refractor of the Nice Observatory. In 1978, Paul COUTEAU published the first book in French devoted to double stars: L'observation des étoiles doubles visuelles. That book triggered the interest of more amateur astronomers for double stars and indirectly influenced the creation of a group of double star observers which was transformed into the Commission des Étoiles Doubles
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Dusanic, Slobodan. "Prosopographic notes on roman mining in Moesia superior: The families of wealthy immigrants in the mining districts of Moesia superior." Starinar, no. 56 (2006): 85–102. http://dx.doi.org/10.2298/sta0656085d.
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The author analyzes epigraphic evidence (fresh or based on documents the reading and/or interpretation of which has been revised in sections I-V) to show that Roman mining in Moesia Superior, under the Principate, was largely based on private - frequently senatorial - financial investment. I An unpublished inscription (IInd cent.?) from the Kosmaj argentariae discloses two Publii Fundanii, obviously members of the same family which was to produce P. Fundanius Eutyches, a colonus of the near-by Rudnik mines early in Septimius Severus' reign (IMS I 168). It is perhaps no simple coincidence that, long before, a P. Fundanius Hospes was active in the ferrariae of Noricum (CIL III 4915 a, Magdalensberg); as is well known, the involvement of wealthy Romans in the mining business tended to be hereditary. II The set of Dardanian lead-ingots found at the wreck site of Caesarea Palaestinae registers interesting stamps (Ann. ?p. 1999, 1683; Domitianic). Their testimony can be understood, on a number of points, more completely than has been done by previous editors (I shall discuss the ingots' epigraphic problems in a separate article). Here, let us note that the stamp (d) P.T.R., is best read P(ublius) T(arius) R(ufus) (the genitive construction being possible, too). Like several other families from Liburnia and Nedinum itself (e.g. the Quinti Gnorii), the Tarii Rufi (there seems to be independent evidence that they employed the praenomen Publius [CIL III 2877] among other praenomina) will have invested their money in the mining of Illyricum/Upper Moesia. This state of affairs probably went back to L. Tarius Rufus, cos. 16 BC. III As briefly noted by A. Evans (and more or less forgotten by later scholars), there was a Roman mining region in northwest Dardania (Mokra Gora - Suva Planina), which has left traces in the toponymy (the eloquent Serbian place-name "Rudnik"), archaeological material (including "traces of the ancient workings "), and inscriptions (the mining aspects of which remained unobserved). The presence of rich people/bearers of significant gentilicia should be pointed out here; it tends to be overlooked by the epigraphists. A Greek inscription from Rudnik (Spomenik 71 [1931] 92 no. 215) records a Fulcinius (line 1), who probably originated in Macedonia and may have been a distant successor to the Fulcinius figuring as quaestor in the province's Fasti for 148 BC. The economic expansion of the Fulcinii from Macedonia to the mining districts in the north obviously went via Scupi (IMS VI 121). Another inscription of the same provenance was erected by a Paconius (Spomenik 71[1931] 92 no. 213, with photograph), certainly connected with the city ?lite of S(plonum?) and Risinium, perhaps also with merchants from Delos and Thessalonice. IV The honorary base of Gamicus conductor an(nis) X, lib(ertus) Pont[io(rum)], found at Agio Pnevma not far from Siris (Ann. ?p. 1986, 629, slightly modified), is of double interest. On the one hand, it provides an instructive piece of evidence on iron-mines in the south of Macedonia. (A number of facts tend to indicate their role in the matter: Gamicus' title of conductor, his being a freedman of the Pontii [? to be identified with the senatorial family of the Pontii from Dardania, whose social success, it is generally assumed, must have owed much to the mines in the neighbourhood of Ulpiana], and the mineral wealth of the Strymon region) If Gamicus is really taken to have belonged to the Dardanian branch of the Pontii as their libertus, i.e. the prominent family owning i.a. the ferrariae in Macedonia, their interest in iron may be attributed to the intensity of their need for tools, typical of people possessing mines as well as latifundia. On the other hand, despite the silence of scholars on the subject, it seems that the Gamicus of Ann. ?p. 1986, 629, must be identified with the Gamicus of the Mursan dedication reading [I.]O.M./[pr]o salute/C. Iul. Agatho/pi c(onductoris)/ f(errariarum) Panno5/niar(um) itemq. provinciar(um) / transmarinar(um) / Gamicus ark(arius) / v.s.l.m. (Fitz Verwaltung Pannoniens, 740 f. no. 2; early Severan). Two circumstances favour the identification - the comparative rarity of the name Gamicus and the fact that the conductor as well as the arcarius served in ironmines (under the regime of conductoriate). Probably, Gamicus was a slave of Agathopus' Iulii first; after their being replaced by the Pontii at the head of a part (doubtless the south-eastern one) of the complex of the iron-mines formerly administered by Agathopus, he was taken over by the Pontii (? related to the Dardanian family of that name which has just been discussed) who manumitted him. Writing of the personnel of the portorium Illyrici (whose case naturally, was similar), P. ?rsted noted an analogous practice: "?new conductores bought the slaves of the departing conductor" (Roman Imperial Economy?340). If the foregoing deductions prove accurate, they can lead to a number of comments concerning the administrative and prosopographic history of the iron-mines in Illyricum. V In the last section of the article, the inscriptions from the Scupian dossier of the (senatorial) Libonii are discussed (IMS VI 27, 75, 167 ?now lost?, and 224 ?discovered at Lopate nr. Kumanovo?). New readings and interpretation of CIL III 8227 = IMS VI 167 (with R. Ardevan's suggestions) have been proposed. We are led to the conclusion that the Libonii constituted another senatorial family with estates in Moesia Superior (Dardania) that sought profit from mining. This would explain the two interesting features of the text of IMS VI 167 which have been overlooked/misinterpreted by previous editors. First, the gentile Libonii (not Sibonii or Sidonii) can be seen among the lettertraces of lines 1 and 6. Second, a mining title occurs in lines 4/5: (procurator, vilicus sim) arg(entariarum) (?) / [D]ar[d(anicarum)]. Palaeographical and onomastic considerations sustain the former point (note that IMS VI 27 and 167 share the cognomina Maxima /Maximus and Severus). The latter point recalls the fact that the Kumanovo territory, to the north of Scupi, is known for its Roman mines of argentiferous lead; for Lopate, where the Le/ibonian inscription IMS VI 224 was found, see TIR K 34,VIII d.