Journal articles: 'Overhead conductors'

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Bedialauneta, Miren T., Igor Albizu, Elvira Fernandez, and A. Javier Mazon. "Uncertainties in the Testing of the Coefficient of Thermal Expansion of Overhead Conductors." Energies 13, no. 2 (January 14, 2020): 411. http://dx.doi.org/10.3390/en13020411.

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Overhead lines can be replaced by high temperature low sag (HTLS) conductors in order to increase their capacity. The coefficients of thermal expansion (CTE) of the HTLS conductors are lower than the CTE of conventional conductors. The utilities and conductor manufacturers usually carry out the verification of the CTE of the overhead conductors in an actual size span. The verification is based on the observation of the change of the conductor length as a result of the conductor temperature change. This process is influenced by the coefficient of thermal expansion to be verified. However, there are other factors that also affect it. This paper analyzes the effect of some of the uncertainty sources in the testing of the coefficient of thermal expansion of the overhead conductors. Firstly, the thermal expansion process is described and the uncertainty sources related to the conductor and the line section are identified. Then, the uncertainty sources and their effect on the CTE testing are quantified.

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Mamala, Andrzej, Tadeusz Knych, Beata Smyrak, Paweł Kwaśniewski, Grzegorz Kiesiewicz, Michał Jabłoński, and Wojciech Ściężor. "An Analytical Model for the High Temperature Low Sag Conductor Knee Point Determination." Key Engineering Materials 641 (April 2015): 173–80. http://dx.doi.org/10.4028/www.scientific.net/kem.641.173.

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The modern high voltage power overhead lines operate with high temperature low sag (HTLS) conductors due to possibility of the current capacity increase. HTLS conductors are material and technological advanced solutions. The main advantage of HTLS conductors is a special designed operation conditions which cause the transformation of tensile stresses from the external aluminium base layers to the core. The conditions of this transformation are called “knee point” because a rapid change of the conductor sag - temperature relationship is observed. Prediction of conditions of the “knee point” temperature (KPT) is a key problem during overhead line design. The KPT is a function of different factors like conductor materials properties, conductor design, span parameters, sagging procedures and overhead line exploitation conditions. The paper presents an original theoretical model for HTLS conductors KPT calculations and shows some examples and comparisons of the different conductor designs and parameters.

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Volokhovskiy, Vasily, Vasily Sukhorukov, and Victor Tzukanov. "Strength Assessment of Deteriorated OHL Conductors and Earth Wires Based on Non-Destructive Testing." Key Engineering Materials 569-570 (July 2013): 1156–63. http://dx.doi.org/10.4028/www.scientific.net/kem.569-570.1156.

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Safety operation of overhead lines depends on many factors including strength of conductors and earth wires. Therefore worn-out or defective conductors or earth wires must be detected. Estimation of conductor technical conditions is based on comparison of revealed flaws with requirements of overhead line project and build documentation. It is well known that conductors are affected by corrosion, friction and fatigue wear. All this factors may cause loss of strength and even breakage of conductor. Steel core is the most important part of conductor when it comes to mechanical loads. That is why it is very important to know actual technical conditions of steel core of conductor. Worn or defective wires must be repaired or replaced. Principles of strength assessment of deteriorated of steel-aluminum conductors and steel earth wires based on magnetic non-destructive testing technique are presented. The retention of overhead line conductor and earth wire is one of the most reasonable ways to eliminate the unacceptable clearances. The allowable magnifying tension, regarding the reliable operation, is set relying upon the non-destructive testing of conductors or earth wires in actual state. The measured loss of metallic cross-section area due to abrasion, corrosion etc. and local wire breaks are treated as input data for mechanical model of objects under test. The residual strength estimates give the specialists network company further information that helps to make a valid decision on testing time-limit and policy. Some results of assessing the strength of overhead line conductors and earth wires according to the NDT data are demonstrated.

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Mišák, Stanislav, Štefan Hamacek, and Mikołaj Bartłomiejczyk. "Verification of a Novel Method of Detecting Faults in Medium-Voltage Systems with Covered Conductors." Metrology and Measurement Systems 24, no. 2 (June 27, 2017): 277–88. http://dx.doi.org/10.1515/mms-2017-0020.

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AbstractThis paper describes the use of new methods of detecting faults in medium-voltage overhead lines built of covered conductors. The methods mainly address such faults as falling of a conductor, contacting a conductor with a tree branch, or falling a tree branch across three phases of a medium-voltage conductor. These faults cannot be detected by current digital relay protection systems. Therefore, a new system that can detect the above mentioned faults was developed. After having tested its operation, the system has already been implemented to protect mediumvoltage overhead lines built of covered conductors.

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Badibanga, Remy, Thiago Miranda, Pedro Rocha, Jorge Ferreira, Cosme da Silva, and José Araújo. "The effect of mean stress on the fatigue behaviour of overhead conductor function of the H/w parameter." MATEC Web of Conferences 165 (2018): 11001. http://dx.doi.org/10.1051/matecconf/201816511001.

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The objective of this work is to evaluate the effects of mean stress on the fatigue behaviour of an All Aluminium Conductor (AAC Orchid), Aluminium Conductor Steel Reinforced (ACSR Tern), and an Aluminium Conductor Alloy Reinforced (ACAR 750 MCM). In this sense, 72 fatigue tests on overhead conductors were performed using different values of H/w parameter. Based on the experimental results, the parameters which describe the fatigue behaviour of the conductors were determined after generating theirs S-N curves. In the assessment of the mean stress effects on the fatigue life, Goodman and Gerber’s relations were fitted to evaluate the use of such models for the conductors. It was observed that the evaluation of the mean stress effect on the overhead conductor could be made by using the fatigue relations.

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Varygina, A. O., and N. V. Savina. "Calculation the current carrying capacity of the new generation overhead lines conductors." Power engineering: research, equipment, technology 22, no. 4 (November 15, 2020): 3–15. http://dx.doi.org/10.30724/1998-9903-2020-22-4-3-15.

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Currently, there is an increase in power flows along power lines. An important task for the development of the power grid complex is to increase the current-carrying capacity of existing power lines. The use of advanced conductors has become a successful technical solution for this purpose. "New generation conductors" are modern conductors that have advanced mechanical and electrical properties and characteristics. Thus, it has become important to have information about the maximum operation temperature and current limits of the overhead line with new conductors. The approximate current-carrying capacity in Amperes is the value of current at which the conductor temperature reaches its maximum permissible value. It determines the maximum current load of overhead power lines. For traditional steelaluminum conductors, there are several methodological approaches to determining the maximum current load. This fact complicates the definition of an approach to calculating the current carrying capacity for advanced conductors. Nevertheless, the general basis of all methodological approaches is the thermal balance of the conductor. The purpose of this article is to assess the possibility of adapting the method of calculating the approximate currentcarrying capacity of traditional conductors to the calculation of advanced conductors. The article deals with advanced conductors of various brands of comparable cross-section with the classic ACSR 240/39. This work provides information about the selected conductors, their characteristics and design features. The paper shows a mathematical model for calculating the approximate current-carrying capacity of a conductor and shows calculating results for selected conductors. According to the results of analysis and calculations, the adaptation of the presented mathematical model is possible if we refine its parameters and coefficients.

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Deng, Yuan Jing, Jun Chao Yu, Kai Quan Xia, and Lin Yang. "Corrosion Conditions Analysis of In-Service ACSR Overhead Lines." Applied Mechanics and Materials 446-447 (November 2013): 753–58. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.753.

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The corrosion conditions of in-service aluminum conductor steel reinforced (ACSR) overhead lines in typical climate were studied by using macroscopic and microscopic methods. According to its operating environment, the corrosion causes were also analyzed. It is found that the corrosion of the outer aluminum stranded conductors is more serious than other parts. And partial corrosion pits have been found on the outer layers of aluminum stranded conductors. While there is no obvious corrosion appeared on the steel core matrix. Additionally, corrosion products can reduce the corrosion rate of aluminum stranded conductors but accelerate corrosion of the steel core. Through this research, more attention should be paid to monitor the aluminum stranded conductors.

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Zheng, Wei, Xizhong Li, Zhongkai Xu, Zhuochen Jin, and Yang Liu. "Research on corrosion mechanism of overhead conductor." E3S Web of Conferences 233 (2021): 01085. http://dx.doi.org/10.1051/e3sconf/202123301085.

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During the operation of overhead conductors, conductors are corroded to varying degrees by the smoke and dust, harmful gases from factories around the lines, or in corrosive salt fog atmosphere in coastal and island areas, as well as humid and hot weather conditions. In this paper, through the study of the corrosion mechanism of the conductor, the types of the corrosion are analyzed, and the factors leading to the corrosion and the corrosion process are analyzed by selecting the steel cored aluminum stranded wire, so as to provide theoretical basis for the development of anti-corrosion wire and the judgment of corrosion detection.

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Liu, Yongdou, Zhiwei Chen, and Quan Gu. "Numerical Algorithms for Calculating Temperature, Layered Stress, and Critical Current of Overhead Conductors." Mathematical Problems in Engineering 2020 (April 30, 2020): 1–14. http://dx.doi.org/10.1155/2020/6019493.

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Accurate calculation of temperature, stress, sag, and critical current (corresponding to critical temperature) of operational overhead conductors is important for ensuring the strength and sag safety of overhead lines. Based on 2D steady-state heat transfer equations, this article studies the temperature fields of the cross section of typical electrified conductors and establishes numerical simulation methods for calculating the layered stress, sag, and critical temperature. Using the algorithm, the relationship between the critical temperature and characteristics of conductors (e.g., the sag and tensile force) is studied. The results are verified by a comparison with the test results for heat-resistant aluminum alloy conductors JNRLH1/G1A-400/65 and JNRLH1/G1A-630/55. Finally, the paper studies the relationship between the critical temperature of the conductor and its most sensitive factors.

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Zhao, Xin Ze, Zhen Xing Yang, Mei Yun Zhao, Lei Wang, and Zhi Cheng Fu. "Analysis on Corona Discharge Characteristics of the Overhead Conductor." Advanced Materials Research 1092-1093 (March 2015): 233–37. http://dx.doi.org/10.4028/www.scientific.net/amr.1092-1093.233.

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LGJ150/25 steel core aluminum stranded wires were selected as the test wires, and the aeolian vibrations which work in different cycle times of wire that is under the conditions of dry and acidic corrosion were simulated by the self-made test bed. The electronic number of corona discharge of each pre-set conductor was measured, when applying AC high voltage on the wearing wires step by step,so that the corona inception voltages of the conductors could be confirmed. And the effect of the vibration cycle times and environmental conditions on the corona discharge was researched. Taking the sum of all aluminium stands wear area of a pre-set wire as the fretting wearing capacity, the relationship between the wire wearing capacity and the corona discharge was studied. The results indicate that the corona inception voltages of the conductors decrease with the increase of the cycle times and the wires wear capacity. In general, the wear capacity of the acidic corrosion conductors is larger, and its corona inception voltage is lower. Therefore the decrease of the conductor fretting wear can effectively reduce the corona loss of transmission lines and other hazards.

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11

Jiang, Yu Ze, Zhen Guang Liang, Can Li, and Bin Xiang Du. "Effect of Phase Sequence Layout on Electric Field under Overhead Lines." Advanced Materials Research 960-961 (June 2014): 921–24. http://dx.doi.org/10.4028/www.scientific.net/amr.960-961.921.

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This paper discusses effect of phase sequence layout on electric field under overhead lines. Charge simulation method is used. Examples of two circuit overhead lines and four circuit overhead lines show that phase arrangment of lowest height conductors has major influence and phase arrangment of middle height conductors has lesser influence on electric field under overhead lines. Interlacing placed lowest height conductors with different phase and phase arrangement of middle height conductors different from that of lowest height conductors help to reduce electric field.

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12

Azam Khan, Amir, David Bong Boon Liang, Andrew Ragai Henry Rigit, Lim Soh Fong, Al-Khalid Othman, and . "Corrosion Study of Galvanized Ultra High Strength Steel Reinforced Overhead Transmission Conductors." International Journal of Engineering & Technology 7, no. 3.18 (August 2, 2018): 83. http://dx.doi.org/10.14419/ijet.v7i3.18.16681.

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Overhead high voltage transmission conductors used worldwide are produced in several configurations. A multi-strand conductor of the type ACSR330 is typically used for 275 kV overhead transmission lines. The conductor is composed of 7 inner strands of Ultra High Strength Galvanized Steel for the mechanical support of the conductor and 26 strands of high conductivity Aluminum wires meant for power transfer over long distances. During the use, weather conditions and power fluctuations tend to degrade the properties of these conductors. In the present work, study of the state of galvanization and oxidation of an ACSR330 conductor is undertaken with a view to understand the effectiveness of the loss in corrosion protection and changes in the zinc coating on the galvanized steel strands after use for 25 to 30 years. The Scanning Electron Microscopy (SEM), X Ray Diffraction (XRD) and Energy Dispersive Analysis through X rays (EDAX) provide a very useful insight into the state of the conductor and gives important information to the strategic decision maker, whether or not to replace the conductor. It was observed in the present study that the zinc coating diffuses inside the steel strand under temperature and time effect. This unique study on the used conductors also reveals that the morphology of the coating and its interface structure changes significantly compared to an unused conductor of the same age.

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13

Yaroslavskiy, D. A., V. V. Nguyen, M. F. Sadykov, M. P. Goryachev, and A. A. Naumov. "Model of own harmonic conductor oscillations for tasks of monitoring the status of airline power transmission lines." Power engineering: research, equipment, technology 22, no. 3 (September 8, 2020): 97–106. http://dx.doi.org/10.30724/1998-9903-2020-22-3-97-106.

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The article substantiates the relevance of the inspection of overhead power lines by determining the mechanical loads of the conductors. The conductor sways under the action of external loads and variable internal mechanical loads. The conductor behaves in span like a pendulum. Using the inclinometric method, it is possible to determine the deviations of the conductor in space from its equilibrium position. Having restored the geometry of the conductor in the span of an overhead power line, mechanical loads can be determined. A model of the harmonic oscillations of the conductor in flight is derived to assess the mechanical loads of the conductor overhead power lines. This mathematical model is based on mathematical models of a flexible thread and a model of a physical pendulum. A conductor is a physical pendulum, where the conductor acts as the body, and in the role of the fixed axis of rotation, a straight line passing through the suspension points of the conductor. The developed model allows you to determine the arrow of its sag from the period of oscillations of the conductor in the span. The article considers algorithms for calculating the conductor sag arrows for two cases: the conductor suspension points are at the same height; conductor suspension points are at different heights. A theoretical calculation is given for a model of a span overhead power line with an estimate of the sensitivity of the developed model and its error in determining the sag of the conductor. Using the arrow of the conductor sag, you can restore its geometry, and hence the mechanical load of the conductor. Therefore, knowing the initial geometric parameters of the span of the overhead power line and the current period of the conductor’s oscillations, it is possible to examine its current state.

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Gomez, Juan C., E. Florena, G. Zamarillo, and Juan C. Amatti. "Cables and conductors protection, part II: overhead conductors." IEEE Latin America Transactions 11, no. 1 (February 2013): 432–38. http://dx.doi.org/10.1109/tla.2013.6502842.

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15

Murín, Justín, Juraj Hrabovský, Roman Gogola, and František Janíček. "Dynamic Analysis of Overhead Power Lines after Ice–Shedding Using Finite Element Method." Journal of Electrical Engineering 67, no. 6 (December 1, 2016): 421–26. http://dx.doi.org/10.1515/jee-2016-0061.

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Abstract In this paper, the analysis of ice-shedding from ACSR conductors to its swing up height and vibration using Finite Element Method (FEM) is presented. For the numerical simulations the effective material properties of the ACSR conductor are calculated using the homogenisation method. Numerical analysis concerning vibration of one and triple-bundle conductors with icing for a whole range or on their certain parts are performed. The impact of ice-shedding to the mechanical tension in the conductors at the points of attachment is investigated and evaluated. Identification of the impact of ice-shedding from the ACSR conductors on its mechanical state may contribute to increasing the safety and quality of an electrical transmission system.

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Zhao, Mei Yun, Zheng Lin Liu, Xin Ze Zhao, and Rui Feng Wang. "Simulation Study on Amplitude of the Overhead Line Based on Simulink." Applied Mechanics and Materials 316-317 (April 2013): 161–66. http://dx.doi.org/10.4028/www.scientific.net/amm.316-317.161.

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Aeolian vibration often occurs in the high-voltage transmission overhead lines, and the amplitude of conductors has close relationship with conductors fretting wear. It is very difficult to measure actual amplitude of working conductor, so obtaining the amplitude of the conductor by the means of simulation is of practical significant to research quantitatively the relationship of the amplitude and the fretting wear. In this paper an imitation test-bed was built. The maximum amplitudes in the different location of a conductor in a test condition were obtained by Simulink software simulating, and the results were compared with the maximum amplitudes obtained by experimental test. The result of this comparison showed that between of them were of good similarity, and the locations of vibration nodes and maximum amplitudes were basically same. It was proved to be feasible that the aeolian vibration amplitude of the overhead conductor in kinds of conditions could be obtained by Simulink software simulating.

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Savadjiev, K., and M. Farzaneh. "Flashover between overhead line conductors." IEEE Transactions on Power Delivery 13, no. 2 (April 1998): 579–86. http://dx.doi.org/10.1109/61.660931.

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Castro, Pablo, Ramón Lecuna, Mario Manana, Maria Jose Martin, and Dolores del Campo. "Infrared Temperature Measurement Sensors of Overhead Power Conductors." Sensors 20, no. 24 (December 12, 2020): 7126. http://dx.doi.org/10.3390/s20247126.

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Efficiency in power lines operation is becoming more crucial as the electrification increases and more renewable energies are connected into the grid. New methods and sensors are being added to create smart grids to face these challenges and conductor temperature sensors are one of them. Contact temperature sensors have several problems regarding safety and electronic damage due to the electromagnetic fields induced on the conductors. The goal of this paper is to describe an infrared temperature measurement sensor and to compare contact and non-contact temperature measurements to estimate the temperature of power lines. Measurements were done for almost a year, storing around 150,000 measures of contact and infrared thermometers for many different weather and load conditions. The results conclude that the infrared system can be successfully used to control the temperature of the overhead conductor within a range of less than 4 ∘C difference with respect to contact temperature methods for the 88% of the samples and less than 6 ∘C for the 99%.

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Wydra, Michał, and Piotr Kacejko. "Power System State Estimation Accuracy Enhancement Using Temperature Measurements of Overhead Line Conductors." Metrology and Measurement Systems 23, no. 2 (June 1, 2016): 183–92. http://dx.doi.org/10.1515/mms-2016-0014.

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Abstract Power system state estimation is a process of real-time online modeling of an electric power system. The estimation is performed with the application of a static model of the system and current measurements of electrical quantities that are encumbered with an error. Usually, a model of the estimated system is also encumbered with an uncertainty, especially power line resistances that depend on the temperature of conductors. At present, a considerable development of technologies for dynamic power line rating can be observed. Typically, devices for dynamic line rating are installed directly on the conductors and measure basic electric parameters such as the current and voltage as well as non-electric ones as the surface temperature of conductors, their expansion, stress or the conductor sag angle relative to the plumb line. The objective of this paper is to present a method for power system state estimation that uses temperature measurements of overhead line conductors as supplementary measurements that enhance the model quality and thereby the estimation accuracy. Power system state estimation is presented together with a method of using the temperature measurements of power line conductors for updating the static power system model in the state estimation process. The results obtained with that method have been analyzed based on the estimation calculations performed for an example system - with and without taking into account the conductor temperature measurements. The final part of the article includes conclusions and suggestions for the further research.

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Liu, Zhao, Honglei Deng, Ruidong Peng, Xiangyang Peng, Rui Wang, Wencheng Zheng, Pengyu Wang, Deming Guo, and Gang Liu. "An Equivalent Heat Transfer Model Instead of Wind Speed Measuring for Dynamic Thermal Rating of Transmission Lines." Energies 13, no. 18 (September 8, 2020): 4679. http://dx.doi.org/10.3390/en13184679.

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With the increase in electricity demand, the ampacity calculation based on the dynamic thermal rating (DTR) technology is increasingly significant for assessing and improving the power transfer capacity of the existing overhead conductors. However, the DTR models now available present some inadequacies in measurement techniques related to wind speed. Therefore, it is essential to propose a new model instead of wind speed measuring in DTR technology. In this paper, the influence analysis of various weather parameters on the conductor ampacity is carried out by using the real weather data. Based on the analysis, it is confirmed that the impact of wind speed is significant, especially in the case of the low wind speed. Moreover, an equivalent heat transfer (EHT) model for DTR technology is proposed instead of wind speed measuring. For this EHT model, the calculation of conductor ampacity is realized through investigating the correlation of heat losses between the heating aluminum (Al) ball and conductor. Finally, combined with the finite element method (FEM), the EHT model proposed in this paper is verified by the Institute of Electrical and Electronic Engineers (IEEE) standard. The results indicate that the error of the EHT model is less than 6% when employing the steady thermal behavior of the Al ball to calculate the ampacity. The EHT model is useful in the real-time thermal rating of overhead conductors. It can increase the utilization of overhead conductors while also avoiding the limitation of the existing measurement techniques related to wind speed.

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DANILIN, A. N., L. N. RABINSKIY, and S. I. ZHAVORONOK. "DEFORMATION OF THE HELICAL TYPE WIRE STRUCTURES." Periódico Tchê Química 16, no. 33 (March 20, 2019): 583–601. http://dx.doi.org/10.52571/ptq.v16.n33.2019.598_periodico33_pgs_583_601.pdf.

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Analysis of overhead power transmission lines (OPL) involves the simulation of statics and oscillation. Solving such problems strictly requires the proper accounting of the internal conductor structure, in particular for power safety and reliability systems of information-telecommunication supply of aerodromes and aircraft systems, as well as for overhead transmission lines subjected to intense wind, especially in icing conditions. Due to the complexity of wire structures, known issues arise in the estimates of their deformations, stiffness, bearing capacity, etc. For instance, the bending stiffness of the conductor can vary considerably. Consequently, the stiffness can vary along the conductor axis as well as in time. This paper proposes a new deformation model of wire structures similar to typical OPL conductors. Such structures include not only conductors and cables, but spiral clamps intended for tension, suspension, joining, protection, and repair of conductors. Based on energy averaging each wire layer is considered as an equivalent elastic anisotropic cylindrical shell. Therefore a conductor or a spiral clamp can be modeled as a system of shells nested into each other and interacting by means of pressure and friction forces. In the process of the study, calculations were made that made it possible to formulate equations for the matrices of flexibility and cruelty of spiral structures. The interaction problem for a tension clamp with an external wire layer of a conductor has been formulated and solved. Finally, the mechanism of the force transfer from the clamp on the conductor has been investigated.

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Jerrell, J. W., W. Z. Black, and T. J. Parker. "Critical span analysis of overhead conductors." IEEE Transactions on Power Delivery 3, no. 4 (1988): 1942–50. http://dx.doi.org/10.1109/61.194004.

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Pytlak, Pawel, Petr Musilek, Edward Lozowski, and Janos Toth. "Modelling precipitation cooling of overhead conductors." Electric Power Systems Research 81, no. 12 (December 2011): 2147–54. http://dx.doi.org/10.1016/j.epsr.2011.06.004.

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Luqman, H. M., M. N. R. Baharom, N. A. M. Jamail, N. A. Othman, R. Abd Rahman, M. F. M. Yousof, and Irshad Ullah. "Conductor sag comparison for 132 kV overhead transmission line improvement in Malaysia." Bulletin of Electrical Engineering and Informatics 9, no. 1 (February 1, 2020): 39–47. http://dx.doi.org/10.11591/eei.v9i1.1863.

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This paper presents conductor sag comparison for 132 kV overhead transmission line improvement in Malaysia. Increasing industrialization and population growth around the world demands higher electricity supply. Power generation has yet to decline but transmitting sufficient electricity to consumers is worrisome due to scarce land space occupied by rapid urbanization. Hence reconductoring method was chosen to improve existing 132 kV overhead transmission line in Malaysia. A group of selected conductors were chosen for comparison where the high temperature low sag conductor stood out the most producing up to 40% sag reduction. This paper focuses on providing conductor alternatives to improve maximum sag of lowest conductor to ground for 132 kV transmission line in Malaysia in accordance to her climate and geographical factor.

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Smyrak, Beata, Tadeusz Knych, Andrzej Mamala, and Kinga Korzeń. "Rheological Inactivity of AIMgSi Conductors (AAAC) in Trend of Negative Stress Gradients." Materials Science Forum 765 (July 2013): 808–12. http://dx.doi.org/10.4028/www.scientific.net/msf.765.808.

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The authors of this paper present the research results of low temperature creep of AlMgSi (6101) wires and AAAC - All Aluminium Alloy Conductor. The conductor is made from AlMgSi wires (diameter 2.99 mm). Based on theoretical analysis it was proved that creep of an overhead conductors depends on the relation between stress and temperature of conductor and the span geometry. Thus the objective of the paper is to determine the wire and conductor creep under the conditions of stress drop. On the basis of the research it has been observed that the creep of both the AAAC conductor and the AlMgSi wires temporarily stopped.

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Boniardi, Marco, Silvia Cincera, Fabrizio D'Errico, and Chiara Tagliabue. "Fretting Fatigue Phenomena on an all Aluminium Alloy Conductor." Key Engineering Materials 348-349 (September 2007): 5–8. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.5.

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This paper concerns about a failure analysis of an electric all aluminum alloy conductor (AAAC) damaged and broken for fretting fatigue phenomena induced by aeolian vibrations. Life of electric conductors is often reduced by various degradation mechanisms such as repeated bending, fluctuating tension, distortion, fatigue, wear and corrosion phenomena. However the main limiting factor of the electrical conductors is related to aeolian vibrations in the high frequency range (between 5 to 50 Hz). Conductor oscillations may lead to fretting fatigue problems (otherwise called fretting wear) caused by wind excitation, mainly in the suspension clamp regions, spacers or other fittings. The induced aluminium wire fracture imply a drastic reduction in the transmission line service. Vibration dampers are considered the most effective method to extend service life of electric conductors, as they are the means to reduce fretting damage of aluminium wires. The aim of the present work is to investigate the failure of an AAAC conductor of a 400kV overhead transmission line (twin conductors) located in Touggourt Biskra (Algeria); the damaged and broken conductors were operated in-service only for six months without spacers or dampers. Three different types of conductors have been taken as experimental samples: the in-service broken conductor, another in-service damaged conductor and a new conductor from warehouse as terms of comparison. Samples have been analysed to identify the root cause of the failure and to verify the conformity of the conductor elements to the international standards. The investigation has outlined the morphology of the fretting damage: in all cases the fractured wires have shown typical static deformation marks and dynamic fretting wear tangential marks associated with intense presence of Al2O3 debris.

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Lee, Jae-bok, Jun Zou, Benliang Li, and Munno Ju. "Efficient evaluation of the earth return mutual impedance of overhead conductors over a horizontally multilayered soil." COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 33, no. 4 (July 1, 2014): 1379–95. http://dx.doi.org/10.1108/compel-08-2013-0265.

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Purpose – The per-unit-length earth return mutual impedance of the overhead conductors plays an important role for analyzing electromagnetic transients or couplings of multi-conductor systems. It is impossible to have a closed-form expression to evaluate this kind of impedance. The purpose of this paper is to propose an efficient numerical approach to evaluate the earth return mutual impedance of the overhead conductors above horizontally multi-layered soils. Design/methodology/approach – The expression of the earth return mutual impedance, which contains a complex highly oscillatory semi-infinite integral, is divided into two parts intentionally, i.e. the definite and the tail integral, respectively. The definite integral is calculated using the proposed moment functions after fitting the integrand into the piecewise cubic spline functions, and the tail integral is replaced by exponential integrals with newly developed asymptotic integrands. Findings – The numerical examples show the proposed approach has a satisfactory accuracy for different parameter combinations. Compared to the direct quadrature approach, the computational time of the proposed approach is very competitive, especially, for the large horizontal distance and the low height of the conductors. Originality/value – The advantage of the proposed approach is that the calculation of the highly oscillatory integral is completely avoided due to the fact that the moment function can be evaluated analytically. The contribution of the tail integral is well included by means of the exponential integral, though in an asymptotic way. The proposed approach is completely general, and can be applied to calculate the earth return mutual impedance of overhead conductors above a soil structure with an arbitrary number of horizontal layers.

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Rashmi, G. S. Shivashankar, and Poornima. "Overview of different overhead transmission line conductors." Materials Today: Proceedings 4, no. 10 (2017): 11318–24. http://dx.doi.org/10.1016/j.matpr.2017.09.057.

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Chen, S. L., W. Z. Black, and H. W. Loard. "High Temperature Ampacity Model for Overhead Conductors." IEEE Power Engineering Review 22, no. 6 (June 2002): 62. http://dx.doi.org/10.1109/mper.2002.4312314.

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Chen, Shelley L., William Z. Black, and Mike Fancher. "High Temperature Sag Model for Overhead Conductors." IEEE Power Engineering Review 22, no. 9 (September 2002): 62. http://dx.doi.org/10.1109/mper.2002.4312607.

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31

Chen, S. L., W. Z. Black, and M. L. Fancher. "High-temperature sag model for overhead conductors." IEEE Transactions on Power Delivery 18, no. 1 (January 2003): 183–88. http://dx.doi.org/10.1109/tpwrd.2002.801427.

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32

Chen, S. L., W. Z. Black, and H. W. Loard. "High-temperature ampacity model for overhead conductors." IEEE Transactions on Power Delivery 17, no. 4 (October 2002): 1136–41. http://dx.doi.org/10.1109/tpwrd.2002.804003.

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33

Tesar, Alexander, and Jana Kuglerova. "Tuned vibration control of overhead line conductors." International Journal for Numerical Methods in Engineering 48, no. 8 (July 20, 2000): 1215–39. http://dx.doi.org/10.1002/(sici)1097-0207(20000720)48:8<1215::aid-nme945>3.0.co;2-l.

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34

Barrett, J. S., and Y. Motlis. "Allowable tension levels for overhead-line conductors." IEE Proceedings - Generation, Transmission and Distribution 148, no. 1 (2001): 54. http://dx.doi.org/10.1049/ip-gtd:20010019.

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35

Li, Yong Ping, Yang Ni, Zhi Yi Huang, and Yu Cheng Su. "Estimation of Overhead Transmission Lines ACSR Combined Elastic Coefficient." Advanced Materials Research 639-640 (January 2013): 1127–30. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.1127.

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According to the characteristics of the aluminum conductors, coated-steel reinforced (ACSR), combined the feature that isotropic and continuity of the folded yarns, establish the calculated equation of the Poisson ratio of the discrete and anisotropic wires. After given the calculated equation of stiffness of large cross-section wires, we obtained the calculated equation of elastic modulus, shear modulus and Poisson ratio. These wires stiffness not only reflect the characteristics of the composite material, but also provide guidance and reference for the mechanical calculation of the wires and installation of overhead conductor and ground wires and the following equation also has certain value in mechanics calculation and lines of construction.

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36

Yaroslavsky, Danil, Van Vu Nguyen, Marat Sadykov, Mikhail Goryachev, Dmitry Ivanov, and Nikolay Andreev. "Determination the conductor sag according to the period of own harmonic oscillations." E3S Web of Conferences 220 (2020): 01036. http://dx.doi.org/10.1051/e3sconf/202022001036.

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The article substantiates the relevance of the inspection of overhead power lines by determining the mechanical loads of the conductors. The conductor sways under the action of external loads and variable internal mechanical loads. The conductor behaves in span like a pendulum. A model of the harmonic oscillations of the conductor in flight is derived to assess the mechanical loads of the conductor overhead power lines. This mathematical model is based on mathematical models of a flexible thread and a model of a physical pendulum. A conductor is a physical pendulum, where the conductor acts as the body, and in the role of the fixed axis of rotation, a straight line passing through the suspension points of the conductor. The article briefly describes an algorithm for calculating the conductor sag for the case when the conductor suspension points are at the same height. The results obtained using the developed model for calculating the sag of the conductor by its period are compared with the available experimental data. Experimental equipment is described. The error of the method is estimated.

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Abbasi, M. Z., B. Noor, M. A. Aman, S. Farooqi, and F. W. Karam. "An Investigation of Temperature and Wind Impact on ACSR Transmission Line Sag and Tension." Engineering, Technology & Applied Science Research 8, no. 3 (June 19, 2018): 3009–12. http://dx.doi.org/10.48084/etasr.2046.

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Power transmission is mainly based on overhead transmission lines with conductors being supported by transmission towers. Transmission lines are subjected to environmental stress (temperature changes, winds, snow etc), have an impact on the surrounding areas (visual pollution, building restrictions) and experience heavy losses due to resistive, magnetic and capacitive effects. Thus, proper modeling and installation of these conductors are necessary. The conductors are generally installed in a catenary shape to minimize the capacitive effects and to balance the tension. This paper presents an investigation on the sag and tension behavior under different temperature and wind of ACSR (Aluminum Conductor-Steel Reinforced) lines. Four different cases of temperature and wind are tested to calculate sag and tension. Simulation setup is done in ETAP (electrical transient and analysis program). Results are recorded and discussed.

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38

Lu, Jia Zheng, Chun Zhao, Bo Li, Zhen Fang, and Hong Xian Zhang. "A Novel Overhead Ground Wire with Winded Insulated Conductors for Ice-Melting." Advanced Materials Research 614-615 (December 2012): 1168–71. http://dx.doi.org/10.4028/www.scientific.net/amr.614-615.1168.

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Serious icing on overhead ground wires threatens the safe running of power system. Common overhead ground wires are difficult to realize ice-melting. A novel overhead ground wire structure for ice-melting is proposed. Some conductors coated with insulation layer are winded around the galvanized steel wires in a special way. Ice-melting experiments are performed on the novel overhead ground wire. Experimental results show that 30 W per meter of the wire is an economic power while 40 W per meter of the wire is an effective power for ice-melting. Engineering application of the novel overhead ground wire with insulated conductors is carried out. With the light moveable de-icer, onsite experiment is performed. Under the power of 40 W per meter of the wire, a temperature rise of 10 °C is achieved in 30 minutes. The result shows that the novel overhead ground wire can meet the demands of engineering application.

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Lu, Ying, Jian gong Zhang, Zheyuan Gan, and Zhibin Zhao. "Influence of Transmission Line Pitch on Passive Interference." E3S Web of Conferences 64 (2018): 05006. http://dx.doi.org/10.1051/e3sconf/20186405006.

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Passive interference of transmission lines to neighbouring radio stations may affect the effective reception and transmission of radio station signals. Therefore, it is the basis to accurately calculate the electromagnetic scattering of transmission lines including overhead wires and towers under the circumstance of electromagnetic waves from outside. Wherein for radio stations, the overhead conductor is the main factor that affects the radar detection because of the working mode of the radar and other factors. In this paper, in the general case of the application of moment method to carry out passive interference calculations, the overhead lines are assumed to be all the actual wire. The space electric field strength and RCS of the different pitch at different operating frequencies and spaces are obtained. The influence of pitch on passive interference of overhead conductors was analyzed. Thus providing a basis for modeling to save energy and reduce the effects of passive interference provides the modeling basis.

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Sakala, Japhet D. "Improved Calculation of Sag for a Conductor Supported at Unequal Heights." International Journal of Electrical Engineering & Education 45, no. 4 (October 2008): 327–35. http://dx.doi.org/10.7227/ijeee.45.4.6.

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The sag of conductors of an overhead line is determined from the horizontal tension at the lowest point of the conductors. In a conductor supported at unequal heights the lowest point is calculated, together with the horizontal tension, from hyperbolic expressions using an iterative procedure. In practice the hyperbolic functions are usually approximated by their first two terms. While the results are close to the actual values some differences may arise because the approximate methods may not converge to the exact values. The Newton Raphson sag method presented in the paper applies the Newton Raphson method to obtain fast convergence to the exact values. It is inherently more accurate than the classical iterative procedure based on approximating the hyperbolic functions; and the convergence criterion may be set as small as required. The method is also applicable to a conductor supported at equal heights.

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41

Deželak, Klemen, and Gorazd Štumberger. "Seeking the optimal arrangements of overhead power line conductors with conductor sagging consideration." International Journal of Applied Electromagnetics and Mechanics 42, no. 3 (April 1, 2011): 359–68. http://dx.doi.org/10.3233/tad-131670.

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42

Dawalibi, F. "Electromagnetic Fields Generated by Overhead and Buried Short Conductors. Part 1??? Single Conductor." IEEE Power Engineering Review PER-6, no. 10 (October 1986): 32–33. http://dx.doi.org/10.1109/mper.1986.5527601.

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43

Dawalibi, F. "Electromagnetic Fields Generated by Overhead and Buried Short Conductors Part 1 - Single Conductor." IEEE Transactions on Power Delivery 1, no. 4 (1986): 105–11. http://dx.doi.org/10.1109/tpwrd.1986.4308036.

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44

Beryozkina, Svetlana. "Evaluation Study of Potential Use of Advanced Conductors in Transmission Line Projects." Energies 12, no. 5 (March 1, 2019): 822. http://dx.doi.org/10.3390/en12050822.

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Transmission networks recently faced new technical and economic challenges. The direct use of advanced technologies and modern methods could solve these issues. This paper discusses the potential application of straightforward technology such as high-temperature low-sag conductors (HTLScs) as an additional measure for the protection and effective operation of overhead power lines. An evaluation was conducted to determine an approach for selecting the cross-sectional area and type of conductor with respect to a fault current limitation. It showed the potential benefits of using HTLScs based on an assessment of the throughput capacity and up-front capital costs. A case study considered two scenarios: the construction of a new power line and reconductoring of the existing one. The data for a real project with two overhead power lines were used. The obtained results are analyzed and discussed in detail in this paper.

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45

Yang, Jia Lun, Kuan Jun Zhu, Bin Liu, Jia Jun Si, Quan Yin, and Liang Hu Jiang. "Research Progress on Manual Ice Measurement Devices for Overhead Transmission Lines." Advanced Materials Research 765-767 (September 2013): 2272–75. http://dx.doi.org/10.4028/www.scientific.net/amr.765-767.2272.

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Sufficient icing data are very important for the design and operation of power grid in the places with potential accreted ice, meaning that it is necessary to pay due attention to the ice measurement devices. In this paper, the current ice measurement devices are classified into different types according to corresponding classification criteria with the aim of understanding the characteristics of each type of devices. Moreover, the research progress of the manual ice measurement devices are introduced in detail, including the diameter of conductors, the angle between conductor and wind direction. Finally, the existing problems are proposed for the further development of manual ice measurement devices for overhead transmission lines.

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46

Popoli, Arturo, Leonardo Sandrolini, and Andrea Cristofolini. "Reduction in the Electromagnetic Interference Generated by AC Overhead Power Lines on Buried Metallic Pipelines with Screening Conductors." Electricity 2, no. 3 (August 19, 2021): 316–29. http://dx.doi.org/10.3390/electricity2030019.

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This paper presents a numerical study on the reduction in the voltage and current induced on a 13.5 km buried metallic pipeline by an overhead power line. The mitigation effectiveness of different configurations and cross-section shapes of screening conductors is computed by means of a methodology that combines a 2D Finite Element Analysis with circuital analysis. A 35.72% reduction of the maximum induced voltage is obtained when 4 cylindrical steel screening conductors with 8 mm radius are buried 0.25m below the soil surface, along the pipeline path. The maximum induced pipeline current is reduced by 26.98%. A parametric study is also performed, to assess the influence of the per-unit-length admittance to earth of the screening conductors on the mitigation efficacy. The results show that screening conductors may help in reducing the inductive coupling between overhead power lines and buried metallic pipelines, and that the assumption of perfectly insulated screening conductors leads to an underestimation of the produced mitigation effect.

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47

Wang, Rui, Ruidong Peng, Xiangyang Peng, Zhao Liu, Jiajian Huang, Wencheng Zheng, and Gang Liu. "Non-contact Dynamic Capacity-Increasing of Overhead Conductor Based on Cooling Tester (CT)." E3S Web of Conferences 185 (2020): 01078. http://dx.doi.org/10.1051/e3sconf/202018501078.

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The traditional dynamic capacity-increasing technology of overhead conductors needs to monitor the operation state of conductors (temperature, sag, etc.), and the relevant sensors are usually installed directly on the surface of conductors. The installation cost is high, and the operating maintenance is complicated. In this paper, a non-contact dynamic capacity-increasing method for overhead conductors based on CT is proposed. Firstly, the theory of the non-contact dynamic capacity-increasing method for conductors is introduced, and a cooling testing device is designed according to the theory. Then, the cooling index is defined to represent the cooling capacity of the object, and the corresponding cooling indexes for the conductors and the CT are calculated based on the steady-state thermal balance equation. By establishing a cooling correlation model for the conductors and the CT, the calculation for the dynamic ampacity of the conductors can be obtained. Finally, the cooling conditions of cooling testing device at different ambient temperatures and wind speeds are calculated through the finite element simulation method. Combined with the dynamic capacityincreasing method proposed in this paper, the corresponding ampacity value are obtained, and the effect of capacity increase is analyzed. The results show that the non-contact dynamic capacity-increasing method based on the CT has obvious effect in capacity-increasing compared with the static ampacity.

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Erol, Harun, Hicran Tecer, Emine Acer, Coşkun Kadioğlu, and Mehmet Gündüz. "Tensile Strength of Al-Zr Overhead Line Conductors." Materials Science Forum 765 (July 2013): 793–97. http://dx.doi.org/10.4028/www.scientific.net/msf.765.793.

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Aluminium and its alloys are used in all bare overhead energy transmission lines. Researchers and manufacturers, have in the past, made significant improvements in the tensile strength and conductivity of overhead lines. In the present work, the effect of heat treatments on the tensile strength of Al-Zr alloys (Al-0.15, 0.20, 0.25wt.%Zr) has been investigated (all compositions hereafter are described in wt.%). The Al-Zr samples were prepared by using a melt furnace and a continuous casting line. The cast, extruded and drawn samples with different diameters (4, 6, 10 mm) were aged isothermally and isochronally in muffle and tube furnaces. Aging was performed over a wide range of temperatures (350-450 °C) at constant aging times (100 hrs., 125 hrs.) and over a wide range of aging times (50-150 hrs.) at a constant temperature (425 °C). It was found that, aging temperatures, aging times, composition, processing techniques and size of the samples affect the tensile strength.

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49

Rawlins, Charles B. "Flexural self-damping in overhead electrical transmission conductors." Journal of Sound and Vibration 323, no. 1-2 (June 2009): 232–56. http://dx.doi.org/10.1016/j.jsv.2008.12.022.

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50

Barber, K. W., and K. J. Callaghan. "Improved overhead line conductors using aluminium alloy 1120." IEEE Transactions on Power Delivery 10, no. 1 (1995): 403–9. http://dx.doi.org/10.1109/61.368373.

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Journal articles on the topic 'Overhead conductors'

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