scholarly journals Experimental Investigation of Surge Propagation Characteristics on a Substation Grounding System

2021 ◽  
Vol 2096 (1) ◽  
pp. 012113
Author(s):  
V V Kolobov ◽  
M B Barannik ◽  
V V Ivonin
Keyword(s):  
Wave Propagation ◽  
Transmission Lines ◽  
Propagation Velocity ◽  
Electromagnetic Waves ◽  
Mesh Size ◽  
Correct Choice ◽  
Residual Voltage ◽  
Grounding System ◽  
Grounding Grid ◽  
Current Wave

Abstract With the correct choice of the arrester by voltage class and compliance with the calculated protective distance without taking into account the propagation velocity of the current wave on the grounding grid, overvoltages exceeding discharge or residual voltage may occur on the protected equipment, in particular the transformer. Thus, when calculating the installation of the arrester that protects the substation from incoming lightning surges from a transmission lines, it is necessary to take into account the propagation of the current wave on the grounding grid. The propagation velocity of electromagnetic waves in a 150 kV substations grounding grid was measured. The measured wave propagation velocities are in the range of 50–100⋅106 m/s. Thus, the obtained velocity of wave propagation on the grounding grid used in service is several times less than the speed of light. The measured value correlates well with similar experiments conducted for buried conductors located in soils with similar parameters and the results of mathematical modeling for a grounding grid having similar dimensions and mesh size.

scholarly journals Investigation and Optimization of Grounding Grid Based on Lightning Response by Using ATP-EMTP and Genetic Algorithm

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Saeid Gholami Farkoush ◽  
Tahir Khurshaid ◽  
Abdul Wadood ◽  
Chang-Hwan Kim ◽  
Kumail Hassan Kharal ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Power System ◽  
Short Circuit ◽  
Mesh Size ◽  
Grounding System ◽  
Practical Applications ◽  
System A ◽  
Grounding Grid ◽  
Soil Ionization ◽  
Optimized Conditions

A large number of electromagnetic transient studies have been analyzed for finding the overvoltage behavior of power system. A grounding grid of power system is so important for reducing the effect of overvoltage phenomena during a short-circuit event. Two sections are important in grounding system behavior: soil ionization and inductive behavior; this paper focuses on the inductive manner of grounding grid. The grounding grid is considered as a conductor segment; each conductor segment acts as a grounding unit. In this paper, the transient methodology is introduced to investigate the lightning effect on grounding body at each point of grounding grid in normal and optimized conditions. Genetic algorithm is applied for regular and irregular grounding grid to obtain best values of mesh size with the lower ground potential rise (GPR) as compared with the normal condition for more safety. The grounding grid is a combination of inductance, resistance, and capacitance. This model is suitable for practical applications related to fault diagnosis. Several voltages on different positions of grounding grid are described in this paper using ATP-EMTP and genetic algorithm. The computer simulation shows that the proposed scheme is highly feasible and technically attractive.

scholarly journals Anomalous Anderson localization behavior in gain-loss balanced non-Hermitian systems

Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 443-452
Author(s):  
Tianshu Jiang ◽  
Anan Fang ◽  
Zhao-Qing Zhang ◽  
Che Ting Chan
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Waves ◽  
Anderson Localization ◽  
Random Media ◽  
Normal Incidence ◽  
Disordered Media ◽  
One Dimensional ◽  
Gain Loss ◽  
The Waves ◽  
Localization Behavior

AbstractIt has been shown recently that the backscattering of wave propagation in one-dimensional disordered media can be entirely suppressed for normal incidence by adding sample-specific gain and loss components to the medium. Here, we study the Anderson localization behaviors of electromagnetic waves in such gain-loss balanced random non-Hermitian systems when the waves are obliquely incident on the random media. We also study the case of normal incidence when the sample-specific gain-loss profile is slightly altered so that the Anderson localization occurs. Our results show that the Anderson localization in the non-Hermitian system behaves differently from random Hermitian systems in which the backscattering is suppressed.

Transmission lines and wave propagation

1965 ◽  
Vol 53 (10) ◽  
pp. 1682-1682
Author(s):  
R.C. Levine
Keyword(s):  
Wave Propagation ◽  
Transmission Lines

scholarly journals Distortionless wave propagation in inhomogeneous media and transmission lines

1976 ◽  
Vol 34 (2) ◽  
pp. 183-194 ◽  
Author(s):  
V. Burke ◽  
R. J. Duffin ◽  
D. Hazony
Keyword(s):  
Wave Propagation ◽  
Transmission Lines ◽  
Inhomogeneous Media
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