scholarly journals The Time-Varying Characteristics of Overhead Electric Transmission Lines Considering the Induced-Ice-Shedding Effect

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Kunpeng Ji ◽  
Xiaoming Rui ◽  
Lin Li ◽  
Chao Zhou ◽  
Chen Liu ◽  
...  
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Equations Of Motion ◽  
Line System ◽  
Electric Transmission ◽  
Electric Transmission Lines ◽  
Stiffness Matrices ◽  
Ice Shedding ◽  
Adverse Influence ◽  
Detachment Criterion

More ice deposits accreted on conductors or ground wires may be shed off when an overhead electric transmission line is responding to shocks initiated by natural ice shedding. Ice shedding causes the global mass, stiffness, and damping of the tower-line system to vary with time, and the successive shedding effect beyond a trigger event has not been taken into account in previous studies due to the lack of an adequate ice detachment model. In this paper, the ice shedding effect induced by initial shocks was considered in finite element (FE) analysis. An ice detachment criterion, in the way of user-defined element rupture subroutine, was implemented into the main commercial nonlinear FE program ADINA, making it possible to consider the induced-ice-shedding effect numerically. The incremental FE form of the system’s governing equations of motion is presented where the variations in the mass and stiffness matrices of the system are taken into consideration. Taking a transmission line section following natural ice shedding as a case study, the results indicate that neglecting successive ice shedding underestimates the adverse influence of natural ice shedding. The proposed method can help to improve the design and evaluation of transmission lines in cold regions and to ensure their mechanical security.

scholarly journals Predictive Models of Current, Voltage, and Power Losses on Electric Transmission Lines

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
O. M. Bamigbola ◽  
M. M. Ali ◽  
K. O. Awodele
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Predictive Models ◽  
Electrical Energy ◽  
Power Losses ◽  
Electric Transmission ◽  
Power Stations ◽  
Electric Transmission Lines ◽  
Current Voltage ◽  
Civilized Society

A modern and civilized society is so much dependent on the use of electrical energy because it has been the most powerful vehicle for facilitating economic, industrial, and social developments. Electrical energy produced at power stations is transmitted to load centres from where it is distributed to its consumers through the use of transmission lines run from one place to another. As a result of the physical properties of the transmission medium, some of the transmitted power is lost to the surroundings. The overall effect of power losses on the system is a reduction in the quantity of power available to the consumers. An accurate knowledge of transmission losses is hinged on the ability to correctly predict the available current and voltage along transmission lines. Therefore, mathematical physics expressions depicting the evolution of current and voltage on a typical transmission line were formulated, and derived therefrom were models to predict available current and voltage, respectively, at any point on the transmission line. The predictive models evolved as explicit expressions of the space variable and they are in close agreement with empirical data and reality.

scholarly journals Collapse Analysis of a Transmission Tower-Line System Induced by Ice Shedding

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiaxiang Li ◽  
Biao Wang ◽  
Jian Sun ◽  
Shuhong Wang ◽  
Xiaohong Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Transmission Lines ◽  
Progressive Collapse ◽  
Element Model ◽  
Transmission Tower ◽  
Line System ◽  
Finite Element Software ◽  
Transmission Towers ◽  
Ice Shedding ◽  
The Impact

Ice shedding causes transmission lines to vibrate violently, which induces a sharp increase in the longitudinal unbalanced tension of the lines, even resulting in the progressive collapse of transmission towers in serious cases, which is a common ice-based disaster for transmission tower-line systems. Based on the actual engineering characteristics of a 500 kV transmission line taken as the research object, a finite element model of a two-tower, three-line system is established by commercial ANSYS finite element software. In the modeling process, the uniform mode method is used to introduce the initial defects, and the collapse caused by ice shedding and its influencing parameters are systematically studied. The results show that the higher the ice-shedding height is, the greater the threat of ice shedding to the system; furthermore, the greater the span is, the shorter the insulator length and the greater the dynamic response of the line; the impact of ice shedding should be considered in the design of transmission towers.

scholarly journals Classification and direction discrimination of faults in transmission lines using 1D convolutional neural networks

2021 ◽  
Vol 12 (3) ◽  
pp. 1928
Author(s):  
Ahmed Thamer Radhi ◽  
Wael Hussein Zayer ◽  
Adel Manaa Dakhil
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Feature Extraction ◽  
Transmission Line ◽  
Convolutional Neural Networks ◽  
Transmission Lines ◽  
Fault Classification ◽  
Line System ◽  
Direction Discrimination ◽  
Conventional Methods

<span lang="EN-US">This paper presents a fast and accurate fault detection, classification and direction discrimination algorithm of transmission lines using one-dimensional convolutional neural networks (1D-CNNs) that have ingrained adaptive model to avoid the feature extraction difficulties and fault classification into one learning algorithm. A proposed algorithm is directly usable with raw data and this deletes the need of a discrete feature extraction method resulting in more effective protective system. The proposed approach based on the three-phase voltages and currents signals of one end at the relay location in the transmission line system are taken as input to the proposed 1D-CNN algorithm. A 132kV power transmission line is simulated by Matlab simulink to prepare the training and testing data for the proposed 1D- CNN algorithm. The testing accuracy of the proposed algorithm is compared with other two conventional methods which are neural network and fuzzy neural network. The results of test explain that the new proposed detection system is efficient and fast for classifying and direction discrimination of fault in transmission line with high accuracy as compared with other conventional methods under various conditions of faults.</span>

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