scholarly journals Determination of Cumulative Distribution Function of the Crest Value of the Lightning Current Circulating Through Line Surge Arresters

2020 ◽  
Vol 69 (2) ◽  
pp. 11-18
Author(s):  
Goran Levačić ◽  
Alain Xémard ◽  
Miroslav Mesić
Keyword(s):  
Distribution Function ◽  
Transmission Line ◽  
Transmission Lines ◽  
Cumulative Distribution Function ◽  
Cumulative Distribution ◽  
Lightning Strikes ◽  
Surge Arresters ◽  
Lightning Current ◽  
Calculation Results

For the selection and design of line surge arresters (LSA), it is essential to know the characteristics of the lightning current circulating through LSA. When lightning strikes a transmission line, only a part of the lightning current circulates through LSA.This part mostly depends on the point of impact, and the characteristic of the lightning stroke current. The determination of the cumulative distribution function of the lightning current circulating through arresters is presented in first part of the paper. It can be applied on transmission lines where LSAs will be installed to protect the line against the effect of atmospheric discharges.Second part of paper presents the calculation results of the cumulative distribution function of the lightning current circulating through arresters for particular 110 kV transmission line located in an area with high lightning activity.

scholarly journals Dependability of the Exemplary Technical System for Assumed Functions of Defect Density

2016 ◽  
Vol 39 (1) ◽  
pp. 151-161
Author(s):  
Sławomir Stępień ◽  
Justyna Grzesik
Keyword(s):  
Distribution Function ◽  
Standard Deviation ◽  
Cumulative Distribution Function ◽  
Defect Density ◽  
Technical System ◽  
Cumulative Distribution ◽  
Distribution Shape ◽  
Calculation Results ◽  
Over Time

Abstract The analysis of structural dependability of technical system, especially determining the change in dependability over time, requires knowledge on density function or the understanding of cumulative distribution function of components belonging to the structure. Based on previously registered data concerning component defect, it is relatively easy to establish the average uptime of component as well as the standard deviation for this time. However, defining distribution shape gives rise to some difficulties. Usually, we do not have the sufficient number of data at our disposal to verify the hypothesis regarding the distribution shape. Due to this fact, it is a common practice, depending on the case under consideration, to apply the function of defect density. However, the question arises: Does the incorrect determination of types of distributions of components leads to the big error of estimation results of dependability and system durability? This article will not respond to this question in whole, but one will conduct a comparison of calculation results for a few cases. The calculations were conducted for the exemplary technical system.

scholarly journals Assessment of Overvoltage and Insulation Coordination in Mixed HVDC Transmission Lines Exposed to Lightning Strikes

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4217
Author(s):  
Mansoor Asif ◽  
Ho-Yun Lee ◽  
Kyu-Hoon Park ◽  
Ayesha Shakeel ◽  
Bang-Wook Lee
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Protective Level ◽  
Lightning Strikes ◽  
Hvdc Transmission ◽  
Surge Arresters ◽  
Hvdc Transmission Lines ◽  
Lightning Impulse ◽  
Insulation Coordination ◽  
Front Model

Many geographical constraints and aesthetic concerns necessitate the partial use of cable sections in the High Voltage DC (HVDC) transmission line, resulting in a mixed transmission line. The overhead sections of mixed lines are exposed to lightning strikes. The lightning strikes can not only result in flashover of overhead line (OHL) insulators but can enter the cable and permanently damage its insulation if adequate insulation coordination measures are not taken. In this work, we have analyzed the factors that affect the level of overvoltage inside the cable by simulating a fast front model in PSCAD. It has been determined that surge arresters must be provided at cable terminals when the length of cable sections is less than 16 km to limit the core-ground overvoltage within the lightning impulse protective level (LIPL). The level of sheath-ground overvoltage is independent of the length of cable; however, it can be limited within LIPL by lowering the sheath grounding impedance to 1.2 Ω. Insulation coordination measures do not impact the likelihood of OHL insulators’ flashover. The flashover performance of OHL can be improved by lowering the footing impedance of the second tower closest to the cable terminals, which is otherwise most likely to flashover.

DISSONANCE — A MEASURE OF VARIABILITY FOR ORDINAL RANDOM VARIABLES

2001 ◽  
Vol 09 (01) ◽  
pp. 39-53 ◽  
Author(s):  
RONALD R. YAGER
Keyword(s):  
Distribution Function ◽  
Cumulative Distribution Function ◽  
Probability Distributions ◽  
Random Variables ◽  
Cumulative Distribution ◽  
General Properties

We look at the issue of obtaining a variance like measure associated with probability distributions over ordinal sets. We call these dissonance measures. We specify some general properties desired in these dissonance measures. The centrality of the cumulative distribution function in formulating the concept of dissonance is pointed out. We introduce some specific examples of measures of dissonance.

Estimating the cumulative distribution function for the linear combination of gamma random variables

2017 ◽  
Vol 20 (5) ◽  
pp. 939-951
Author(s):  
Amal Almarwani ◽  
Bashair Aljohani ◽  
Rasha Almutairi ◽  
Nada Albalawi ◽  
Alya O. Al Mutairi
Keyword(s):  
Distribution Function ◽  
Linear Combination ◽  
Cumulative Distribution Function ◽  
Random Variables ◽  
Cumulative Distribution
Sign in / Sign up

Export Citation Format

Share Document