scholarly journals On the Transient Response and the Frequency Analysis of Transmission Line Towers

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Mohamed M. Saied
Keyword(s):  
Transient Response ◽  
Characteristic Impedance ◽  
Reduction Technique ◽  
Power Lines ◽  
Vertical Coordinate ◽  
Lightning Strikes ◽  
Numerical Laplace Inversion ◽  
Resonance Frequencies ◽  
Nonuniform Line

This paper proposes an approach to the study of the transient response and the frequency characteristics of power lines' towers, when subjected to lightening strikes. It starts with dividing the nonuniform line representing the tower into a number of sections. From the usually known dependence of the tower's characteristic impedance on the vertical coordinate and the application of a recursive circuit reduction technique, an s-domain expression for the tower input impedance can be obtained. This expression, followed by the numerical Laplace inversion, is utilized for the determination of the tower's transient response. The impedance expression can be also used to determine the tower's resonance frequencies. This was used to demonstrate some potentially critical situations in which the tower is hit by lightning strikes comprising multiple current pulses. The validity of the proposed technique is demonstrated by comparing the achieved results with those already available in the literature for the same case studies.

Lightning and electrical injuries

2020 ◽  
pp. 1696-1700
Author(s):  
Chris Andrews
Keyword(s):  
Case Fatality ◽  
Open Water ◽  
Power Lines ◽  
Psychological Sequelae ◽  
Common Cause ◽  
Lightning Strikes ◽  
Pain Syndromes ◽  
Common Causes ◽  
Overhead Power Lines ◽  
Electrical Injuries

Lightning strikes are rare accidents but carry a 10% case fatality, killing 0.1–0.3 per million population each year. During thunderstorms, the risk is increased by sheltering under trees or by being on open water, on tractors, or in open fields or in outdoor activity. Lightning is considered to cause instant asystole. Immediate cardiopulmonary resuscitation is mandatory. Survivors might develop complications including pain syndromes and psychological sequelae. Burns are generally of minor consequence, unlike electrical injury. The most disabling consequences of the injury is generally the psychological sequelae. Meanwhile, electrocution is the fifth most common cause of workplace death, mainly affecting utilities, mining, and construction labourers. Domestic electrical accidents are common, where contact with overhead power lines, faulty power tools, and particularly using extension cords, are the most common causes, with metal ladders and antennae being particularly dangerous.

scholarly journals Calculation of lightning surges on the high voltage lines. Case of 220 kV line: Ngo -Brazzaville in Congo

2017 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Rodolphe Gomba ◽  
Alphonse Omboua
Keyword(s):  
Power Lines ◽  
Protective Equipment ◽  
Worst Case ◽  
Lightning Strikes ◽  
Lightning Current ◽  
Wave Forms ◽  
Lightning Discharges ◽  
Voltage Wave ◽  
High Level ◽  
Insulation Coordination

The importance of line Ngo-Brazzaville (220 kV, 207 km) requires operators to avoid cuts that can increase the risk of instability. We see it is quite rare that a storm that occurs in areas crossed by this line will not cause triggering. Note that due to lightning discharges are the main causes of unscheduled outages of Congo's power lines; we ignore this during the peak values of voltage wave forms that result. In regions with high level keraunic like Congo, reducing insulation failures due to lightning is a concern in the management of overheads lines. This article clarifies the peak values of the voltages that can be achieved on the network in order to build the operators as to the precautions on the insulation coordination of protective equipment related to lightning. For these calculations surge of atmospheric origin (case of lightning), we considered the bi-exponential function and Heidler function for modeling the wave of the lightning current. This methodology led us to specially treat the effects of direct lightning strikes that constitute the worst case because they generate most destructive shock wave that indirect lightning strikes.

Sign in / Sign up

Export Citation Format

Share Document