Modeling of power transmission lines for lightning back flashover analysis (A case study: 220kV Biyagama-Kotmale transmission line)

Author(s):  
M. Chanaka ◽  
Kusum Shanthi ◽  
Ranjit Perera
Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1561
Author(s):  
Hao Chen ◽  
Zhongnan Qian ◽  
Chengyin Liu ◽  
Jiande Wu ◽  
Wuhua Li ◽  
...  

Current measurement is a key part of the monitoring system for power transmission lines. Compared with the conventional current sensor, the distributed, self-powered and contactless current sensor has great advantages of safety and reliability. By integrating the current sensing function and the energy harvesting function of current transformer (CT), a time-multiplexed self-powered wireless sensor that can measure the power transmission line current is presented in this paper. Two operating modes of CT, including current sensing mode and energy harvesting mode, are analyzed in detail. Through the design of mode-switching circuit, harvesting circuit and measurement circuit are isolated using only one CT secondary coil, which eliminates the interference between energy harvesting and current measurement. Thus, the accurate measurement in the current sensing mode and the maximum energy collection in the energy harvesting mode are both realized, all of which simplify the online power transmission line monitoring. The designed time-multiplexed working mode allows the sensor to work at a lower transmission line current, at the expense of a lower working frequency. Finally, the proposed sensor is verified by experiments.


Author(s):  
Guanghong Tao ◽  
Lijin Fang

Purpose The purpose of this paper is to introduce a robot mechanism designed for power transmission line inspection. The focus for this design is on obstacle-crossing ability with a goal to create a robot moving and crossing obstacle on not only the straight line but also the steering line. Design/methodology/approach A novel four-unit tri-arm serial robot mechanism is proposed. Every novel unit designed for pitching motion is based on parallelogram structure, which is driven by cables and only one motor. There is gripper-wheel compounding mechanism mounted on the arm. The prototype and obstacle environments are established, and the obstacle-crossing experiments are conducted. Findings The novel unit mechanism and robot prototype have been tested in the lab. The prototype has demonstrated the obstacle-crossing ability when moving and crossing fundamental obstacles on the line. The experimental results show that the robot mechanism meets the obstacle-crossing requirements. Practical implications The novel robot technology can be used for defect inspection of power transmission line by power companies. Social implications It stands to lower the intense and risk of inspection works and reduce the costs related to inspection. Originality/value Innovative features include its architecture, mobility and driving method.


2017 ◽  
Vol 40 (11) ◽  
pp. 3273-3292 ◽  
Author(s):  
Vikram Banthia ◽  
Yaser Maddahi ◽  
Kourosh Zareinia ◽  
Stephen Liao ◽  
Tim Olson ◽  
...  

This paper reports technical design of a novel experimental test facility, using haptic-enabled teleoperation of robotic manipulators, for live transmission line maintenance. The goal is to study and develop appropriate techniques in repair overhead power transmission lines by allowing linemen to wirelessly guide a remote manipulator, installed on a crane bucket, to execute dexterous maintenance tasks, such as twisting a tie wire around a cable. Challenges and solutions for developing such a system are outlined. The test facility consists of a PHANToM Desktop haptic device (master site), an industrial hydraulic manipulator (slave site) mounted atop a Stewart platform, and a wireless communication channel connecting the master and slave sites. The teleoperated system is tested under different force feedback schemes, while the base is excited and the communication channel is delayed and/or lossy to emulate realistic network behaviors. The force feedback schemes are: virtual fixture, augmentation force and augmented virtual fixture. Performance of each scheme is evaluated under three measures: task completion time, number of failed trials and displacement of the slave manipulator end-effector. The developed test rig has been shown to be successful in performing haptic-enabled teleoperation for live-line maintenance in a laboratory setting. The authors aim at establishing a benchmark test facility for objective evaluation of ideas and concepts in the teleoperation of live-line maintenance tasks.


Author(s):  
Ngo Minh Khoa ◽  
Nguyen Huu Hieu ◽  
Dinh Thanh Viet

<p>This paper focuses on analyzing and evaluating impact of a Static Var Compensator (SVC) on the measured impedance at distance protection relay location on power transmission lines. The measured impedance at the relay location when a fault occurs on the line is determined by using voltage and current signals from voltage and current transformers at the relay and the type of fault occurred on the line. The MHO characteristic is applied to analyze impact of SVC on the distance protection relay. Based on the theory, the authors in this paper develop a simulation program on Matlab/Simulink software to analyze impact of SVC on the distance protection relay. In the power system model, it is supposed that the SVC is located at mid-point of the transmission line to study impact of SVC on the distance relay. The simulation results show that SVC will impact on the measured impedance at the relay when the fault occurs after the location of the SVC on the power transmission line.</p>


Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1193 ◽  
Author(s):  
Zuzana Bukvisova ◽  
Jaroslava Orsagova ◽  
David Topolanek ◽  
Petr Toman

This work analyses a two-terminal algorithm designed to locate unsymmetrical faults on 110 kV power transmission lines. The algorithm processes synchronized voltage and current data obtained from both ends of the protected transmission line and calculates the distance of the fault. It is based on decomposing the equivalent circuit into the positive-, negative- and zero-sequence components and finding the point where the output voltages of the right and the left side of the transmission line are equal. Compared to the conventional distance relay locator, the accuracy of this method is higher and less influenced by the fault resistance, the parallel-operated line effect and line asymmetry, as discussed in this work. It is, however, very sensitive to the synchronization accuracy. The mathematical model of the power system was created in the PSCAD (Power Systems Computer Aided Design) environment and the computational algorithm was implemented in Mathematica software.


2013 ◽  
Vol 380-384 ◽  
pp. 3425-3428
Author(s):  
Guang Zu Ge ◽  
Bo Tang ◽  
Jian Xiong Zhu ◽  
Yin Huang ◽  
Zi Hang Qu

Resolving the contradiction between trees and power transmission lines in time is an important work to ensure the safety of transmission line operation. While it is difficult to decide the trees trimmed time during the transmission line operation and maintenance, the development of the management information system for protecting distance between transmission lines and trees, which is used to auxiliary predict the date of pruning, is a way to solve the problem. Collected attribute data of transmission lines and trees, the corresponding database is established. Therefore, Visual Basic 6.0 is adopted to develop the software system. Based on the spatial coordinates of line towers, conductors, and tree crown, the three-dimensional mathematical model is established to calculate the spatial distance between the conductor and tree crown. According to the mathematical model, the trees growth rate of year, month and day, respectively, and the protecting distance standard between conductor and tree crown, the system could calculate the actual spatial distance between conductor and tree crown, and auxiliary predict the pruning date.


2012 ◽  
Vol 249-250 ◽  
pp. 798-803
Author(s):  
Zi Fu Zhang ◽  
Zeng Lu Mo ◽  
Jing Du Geng

The breakage of conductor/ground wire seriously affects the secure operation of transmission line. According to the features of UHVDC power transmission lines, the broken conductor model for bundled conductors of continuous span is built and the broken conductor load is calculated; A simulating test was carried out the first time in China for a series of "broken conductor" events on one continuous span on the field to study the dynamic response of the transmission tower because of impact, then the dynamic strain and displacement were obtained. On the basis of the simulation and experiential research results, the paper discussed about the rational values of broken wire loads for the suspension towers of UHVDC.


2015 ◽  
Vol 49 (1) ◽  
pp. 87-94 ◽  
Author(s):  
E. V. Prokopenko

Abstract The fauna and structure of herbdwelling spider assemblages in mesophitic meadow under the high voltage power line near Irliava village (Uzhhorod District, Transcarpathian Region) were analyzed on the material collected by sweep netting. Th e counts were held at five sampling sites: 1) under the wires; 2) at a distance of 50 m; 3) 100 m; 4) 150 m; 5) 200 m. In total, 41 spider species of 14 families were collected. Erigonoplus globipes (L. Koch, 1872) and Hylyphantes nigritus (Simon, 1881) were recorded in the Carpathians for the first time. Th e reduction of total number and species richness of spiders was registered as the approaching to the high voltage power line. Except single finds, no species avoided the wire nearest sites (0-50 m). Abundance of most spider families (except Araneidae) was not significantly influenced by distance from the high voltage power line.


Electrical power generated and transmitted at a long distance away from the power stations is usually affected by inherent transmission line losses. The Ohmic and Corona losses which are predominantly common in power transmission lines are considered in this paper. These two losses are mathematically modeled with and without embedded bundled conductors. The resultant model which is a non-linear multivariable unconstrained optimized equation is minimized using the Hessian matrix determinant method for stability test purposes. The results obtained show that corona losses are minimized with embedded bundled conductors at a very low current value with large spacing distance between the bundled conductors. The decrease in the corona loss which is a consequence of spacing adjustment of the 2, 3, and 4 strands of bundled conductors was plotted using MATLAB 7.14. The plots obtained are in conformity with the inverse relation between corona loss and conductor spacing.


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