95/01555 Modified FT lighting surge analysis of an overhead line-underground coaxial cable system. Part I. Modal analysis of underground cables and overhead lines and effect of subterranean water on cable modal propagation characteristics

The Line Inspection Robot is used to detect the line's defects when it walks on the overhead lines. It will be swinging under its own vibration and the action of wind , due to the robot arms hanging on overhead line alone ,so the dynamic characteristics of robot arm cannot be ignored. In this paper, we establish three-dimensional models of the line inspection robot's manipulator with double manipulators of antisymmetric structure, and conduct solving and post-processing of statics and modal analysis after meshing and applying constraints. The manipulator's low frequencies and vibration modals are drawn, so we can provide a theoretical basis for the reasonable optimization improvements to the line inspection robot's manipulator with double manipulators of antisymmetric structure.

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The choice of optimum cross section for overhead line by economic intervals' method

Scientific Journal of Riga Technical University Power and Electrical Engineering ◽

10.2478/v10144-011-0006-x ◽

2011 ◽

Vol 28 (1) ◽

pp. 37-42 ◽

Cited By ~ 1

Author(s):

Svetlana Guseva ◽

Lubov Petrichenko

Keyword(s):

Cross Section ◽

Current Density ◽

Uncertain Information ◽

Overhead Line ◽

Market Conditions ◽

Overhead Lines ◽

Mathcad Software

The choice of optimum cross section for overhead line by economic intervals' methodIn this paper an approach to choosing the optimum cross section for overhead line in conditions of incomplete and uncertain information is considered. The two methods of such choice are presented: method of economic current density and economic intervals' method. The correction of the economic intervals method is offered under market conditions of costs. As example 20 kV and 110 kV overhead lines with aluminum, copper and ferroaluminum wires are selected. Universal nomograms with different standard cross section are calculated and constructed. The graphics using Mathcad software are offered.

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Photovoltaic Maximum Penetration Limits on Medium Voltage Overhead and Underground Cable Distribution Feeders: A Comparative Study

Energies ◽

10.3390/en14133843 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3843

Author(s):

Sultan Sh. Alanzi ◽

Rashad M. Kamel

Keyword(s):

Power System ◽

Power Factor ◽

Distribution System ◽

Power Flow ◽

Underground Cables ◽

Overhead Lines ◽

Medium Voltage ◽

Load Power ◽

Bus Voltage ◽

Pv Penetration

This paper investigates the maximum photovoltaic (PV) penetration limits on both overhead lines and underground cables medium voltage radial distribution system. The maximum PV penetration limit is estimated considering both bus voltage limit (1.05 p.u.) and feeder current ampacity (1 p.u.). All factors affect the max PV penetration limit are investigated in detail. Substation voltage, load percentage, load power factor, and power system frequency (50 Hz or 60 Hz) are analyzed. The maximum PV penetration limit associated with overhead lines is usually higher than the value associated with the underground cables for high substation voltage (substation voltage = 1.05 and 1.04 p.u.). The maximum PV penetration limit decreases dramatically with low load percentage for both feeder types but still the overhead lines accept PV plant higher than the underground cables. Conversely, the maximum PV penetration increases with load power factor decreasing and the overhead lines capability for hosting PV plant remains higher than the capability of the underground cables. This paper proved that the capability of the 60-Hz power system for hosting the PV plant is higher than the capability of 50 Hz power system. MATLAB software has been employed to obtain all results in this paper. The Newton-Raphson iterative method was the used method to solve the power flow of the investigated systems.

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Study on Reasons of the Falling of the Overhead Line Based on Fault Tree Analysis

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.325-326.590 ◽

2013 ◽

Vol 325-326 ◽

pp. 590-593

Author(s):

Fei Xiang Wei ◽

Yang Song ◽

Xiao Xu Ma ◽

Ying Qian

Keyword(s):

Power System ◽

System Reliability ◽

Fault Tree ◽

Fault Tree Analysis ◽

Power System Reliability ◽

Overhead Line ◽

Qualitative And Quantitative Analysis ◽

Tree Analysis ◽

Overhead Lines ◽

Qualitative And Quantitative

The transmission line is an important part of the power system, its reliability will directly affect the reliability of the power system. The reliability of the overhead line plays a crucial role for the power system reliability. This paper analyze the reasons of the falling of the overhead lines, establish a fault tree, and make qualitative and quantitative analysis of the fault tree.

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Underground cables and overhead lines

Electrical Safety and the Law ◽

10.4324/9781315617626-14 ◽

2017 ◽

pp. 233-246

Author(s):

John M. Madden

Keyword(s):

Underground Cables ◽

Overhead Lines

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Overhead Transmission Line Sag Estimation Using the Simple Opto-Mechanical System with Fiber Bragg Gratings—Part 2: Interrogation System

Sensors ◽

10.3390/s20092652 ◽

2020 ◽

Vol 20 (9) ◽

pp. 2652 ◽

Cited By ~ 1

Author(s):

Krzysztof Skorupski ◽

Damian Harasim ◽

Patryk Panas ◽

Sławomir Cięszczyk ◽

Piotr Kisała ◽

...

Keyword(s):

Fiber Bragg Grating ◽

Bragg Grating ◽

Optical Parameters ◽

Overhead Line ◽

Exact Matching ◽

Small Shift ◽

Optomechanical System ◽

Overhead Lines ◽

Overhead Transmission Line ◽

Experimental Part

This article presents the use of a sensor with fiber Bragg grating along with an interrogation system used for monitoring the overhead lines’ wire elongation. The possible interrogation methods based on adjusted filters were considered. In the experimental part, three types of fiber Bragg grating pairs, characterized by a small shift in spectra in pairs and gratings with exact matching, were examined. The study showed that, by choosing the appropriate mechanical parameters of the elongation transformer with the optical parameters of the sensor and dedicated filter, the optomechanical system can be adjusted to the required range of overhead line wire sag observation. The range of sag depends on the distance between the poles, the wire type, and its real length in the span, which effectively determines the sag.

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An Effective Method to Calculate Frequency Response of Distribution Networks for PLC Applications

Electronics ◽

10.3390/electronics8060649 ◽

2019 ◽

Vol 8 (6) ◽

pp. 649 ◽

Cited By ~ 2

Author(s):

Hongshan Zhao ◽

Weitao Zhang ◽

Yan Wang

Keyword(s):

Frequency Response ◽

Distribution Networks ◽

Dynamic Changes ◽

Binary Function ◽

Underground Cables ◽

Overhead Lines ◽

Medium Voltage ◽

Response Characteristics ◽

Network Topologies ◽

Propagation Matrix

Modelling and estimating power-line communication (PLC) channels are complicated issues due to the complex network topologies, various junctions, and changeable loads. This paper focuses on the frequency response characteristics (FRCs) of medium-voltage (MV) PLC networks with special consideration of two scenarios that are often neglected but generally exist. In the first scenario, the MV distribution network is of the ring topology. In the second scenario, the MV overhead lines and underground cables join at junctions, and the shields of underground cables are grounded with nonzero grounding impedances at the junctions. These conditions lead to the failure of currently popular methods to different degrees. For this reason, we developed an effective method to calculate the FRCs of distribution networks for PLC applications. With this method, the frequency responses of nodes are simply expressed as the binary function of the overall tube propagation matrix and overall node scattering matrix, which is convenient for calculations and analyses. The proposed method was validated by the agreement between the calculated and measured FRCs. The results of two test examples showed that the proposed method performed better in comparison with the traditional approximate method when nonideal grounding conditions were taken into account. The proposed method is also independent of the network topology, so it can adapt to the dynamic changes of the network structure.

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