Detection of disconnection faults and double-phase short circuits in the wires of overhead transmission lines by the location method

2009 ◽  
Vol 80 (2) ◽  
pp. 91-101 ◽  
Author(s):  
R. G. Minullin ◽  
Yu. Ya. Petrushenko ◽  
I. Sh. Fardiev ◽  
E. I. Lukin
Keyword(s):  
Transmission Lines ◽  
Location Method ◽  
Overhead Transmission Lines ◽  
Double Phase ◽  
Short Circuits

scholarly journals Short circuit fire risk assessment in investigating and examining fires caused by emergency modes in overhead transmission lines

2022 ◽  
Vol 6 (4) ◽  
pp. 363-368
Author(s):  
Yu. S. Kozlova
Keyword(s):  
Transmission Lines ◽  
Fire Hazard ◽  
Short Circuit ◽  
Electric Power System ◽  
Ignition Source ◽  
Electrical Network ◽  
Fuel Load ◽  
Overhead Transmission Lines ◽  
Protection Devices ◽  
Short Circuits

Emergency modes (short circuits) in electric power system and equipment are the main technical cause of fires. However, it is not always possible to prove the involvement of a particular operating mode in a fire. The fire hazard can be due to three components: a fuel load, an oxidizer and an ignition source. Since overhead transmission lines are used in an open space, they are oxidized. The presence of a fuel load is confirmed by a fire. The source of ignition should be identified. The aim of the study is to develop an algorithm for assessing the fire hazard for short circuits in overhead transmission lines with 1000 V. The study was conducted using scientific analysis, physical experiment and simulation. The ignition source is due to the appearance of an energy source with parameters sufficient to ignite a fuel load. The probability of ignition in overhead line wires depends on the probability of occurrence of the short circuit itself  ( Qi (v1) ) , the probability of failure of protection devices  ( Qi (v2) ), and the probability that the electric current value in the event of a fault is in the range of fire hazard values (Qi(z)). The values of the first two components are determined on the basis of statistical data, taking into account the theory of reliability. The third component is based on the experiment results. The experimental studies made it possible to establish the ranges of fire hazard values for uninsulated aluminum wires of various cross-sections, thereby providing the possibility of calculating ( Qi (z). Using the data obtained and information about the nature of changes in short-circuit currents and performance characteristics of protection devices, depending on the line length, an algorithm for assessing the fire hazard for a short circuit was developed. The results make it possible to assess the fire hazard for short circuits in various sections of the electrical network, made by overhead transmission lines, and to establish the involvement of sparks generated by short circuits in a fire

A Novel Fault-location Method for HVDC Transmission Lines Based on Concentric Relaxation Principle and Wavelet Packet

2020 ◽  
Vol 13 (5) ◽  
pp. 705-716
Author(s):  
Congshan Li ◽  
Ping He ◽  
Feng Wang ◽  
Cunxiang Yang ◽  
Yukun Tao ◽  
...  
Keyword(s):  
Transmission Lines ◽  
Traveling Wave ◽  
Fault Location ◽  
Wave Attenuation ◽  
Wavelet Packet ◽  
Low Frequency ◽  
Evaluation Process ◽  
Location Method ◽  
Hvdc Transmission ◽  
Instantaneous Energy

Background: A novel fault location method of HVDC transmission line based on a concentric relaxation principle is proposed in this paper. Methods: Due to the different position of fault, the instantaneous energy measured from rectifier and inverter are different, and the ratio k between them is the relationship to the fault location d. Through the analysis of amplitude-frequency characteristics, we found that the wave attenuation characteristic of low frequency in the traveling wave is stable, and the amplitude of energy is larger, so we get the instantaneous energy ratio by using the low-frequency data. By using the method of wavelet packet decomposition, the voltage traveling wave signal was decomposed. Results: Finally, calculate the value k. By using the data fitting, the relative function of k and d can be got, that is the fault location function. Conclusion: After an exhaustive evaluation process considering different fault locations, fault resistances, and noise on the unipolar DC transmission system, four-machine two-area AC/DC parallel system, and an actual complex grid, the method presented here showed a very accurate and robust behavior.

Modeling of overhead transmission lines for trapped charge discharge rate studies

2021 ◽  
Vol 198 ◽  
pp. 107343
Author(s):  
J. Morales ◽  
J. Mahseredjian ◽  
I. Kocar ◽  
H. Xue ◽  
A. Daneshpooy
Keyword(s):  
Transmission Lines ◽  
Discharge Rate ◽  
Overhead Transmission Lines ◽  
Charge Discharge ◽  
Trapped Charge
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