Frequency Characteristics of Overhead Power Lines of Distribution Power Grids with Isolated Neutral and Their Using for Determination of Single-Phase Ground Faults

2019 ◽  
Vol 62 (2) ◽  
pp. 72-84
Author(s):  
Alexander Fedotov ◽  
◽  
Valery Makarov ◽  
Rustem Abdullazyanov ◽  
Georgii Vagapov ◽  
...  
Keyword(s):  
Single Phase ◽  
Frequency Characteristics ◽  
Power Grids ◽  
Power Lines ◽  
Ground Faults ◽  
Isolated Neutral ◽  
Overhead Power Lines

scholarly journals Multiplicity of overvoltages during arc single phase earth faults in 35 kV electrical grids

2021 ◽  
Vol 7 (2) ◽  
pp. 111-116
Author(s):  
Zinoviy Bakhor ◽  
◽  
Andriy Yatseiko ◽  
Roman Ferensovych
Keyword(s):  
Single Phase ◽  
Electrical Equipment ◽  
Power Grids ◽  
Power Lines ◽  
Research Results ◽  
Electrical Grid ◽  
Electrical Distribution ◽  
Electrical Grids ◽  
Isolated Neutral ◽  
Distribution Grids

The arc overvoltages during the single phase to earth faults in electrical distribution grids of 6-35 kV are the object of the research in this paper. The development of 35 kV distribution electrical grids is accompanied by the construction of new overhead and cable power lines. It causes a change of the capacitive earth fault current in the grids and also affects the multiplicity of overvoltages in electrical distribution grids during the single phase to earth faults. The paper shows the research results of overvoltages during arc single phase to earth faults in 35 kV electrical grid with the different grounding modes of a grid neutral (an isolated neutral, a grounded neutral through an arc-quenching reactor, a grounded neutral through a resistor). The calculations were performed on the digital models of the investigation power grids. According to the research results, a mathematical model has been created, which allows obtaining the maximum expected multiplicity of overvoltages in 35 kV electrical grids during the single phase to earth faults. This allows making decisions about the optimal measures for the protection of an electrical equipment insulation taking into account expected values of overvoltages as early as at the stage of pre-design works for the development of such electrical grids.

scholarly journals Determination of the minimum wind speed leading to the galloping of conductors

2020 ◽  
Vol 180 ◽  
pp. 04019
Author(s):  
Muratkali Zhamanbaev ◽  
Diana Ilieva ◽  
Rakhimash Abitaeva ◽  
Bulbul Ongar
Keyword(s):  
Wind Speed ◽  
Nonlinear Equation ◽  
Mutual Influence ◽  
Power Lines ◽  
Oscillatory Process ◽  
Hurwitz Stability ◽  
Aeroelastic Instability ◽  
First Approximation ◽  
Overhead Power Lines

The object of research in this paper is the split phase of overhead power lines. The study of the aeroelastic instability of the icy conductors of the split phase for a multi-span system has already been explored using the method of determining the Hurwitz stability criterion. In multi-span systems, where conductors are interconnected through a garland of insulators, the garlands themselves are involved in an oscillatory process. As a result of this, mutual influence of adjacent spans is observed energy is transferred from one span to another. The paper investigates the aeroelastic instability of the icy conductors of the split phase in the anchor span, which is characterized by two intrinsic features: the attachment point of conductors on the supports is fixed and mutual effects between adjacent spans are not observed. The study of motion instability is carried out by the first approximation method, that is, on the basis of linearization of the nonlinear equation at the equilibrium point and further investigation of the linearized equation in the vicinity of this point. The results of the study are based on the novelty of the carried out experiments - taking into account the peculiarities of the anchor span and the findings based on the analysis of empirical data.

Practical Implementation of the System of Feeder Diagnostics of Single-Phase Earth Faults with Online Distributed Data Collection

2021 ◽  
Vol 64 (2) ◽  
pp. 78-85
Author(s):  
Alexander Fedotov ◽  
◽  
Rafik Basyrov ◽  
Georgii Vagapov ◽  
Ainur Abdullazyanov ◽  
...  
Keyword(s):  
Single Phase ◽  
Practical Implementation ◽  
Distributed Data ◽  
Electrical Networks ◽  
Earth Fault ◽  
Parameters Selection ◽  
Power Substation ◽  
Isolated Neutral ◽  
Ongoing Monitoring

Single-phase earth faults are one of the main problem of the distribution electrical networks with voltage 6 - 35 kV with isolated neutral. Single-phase earth fault is one of the reasons decrease of the power quality and the reliability of power supply. The paper presents the theoretical base of the monitoring parameters selection during the single-phase earth fault process and its practical implementation as an installed system at a power substation with a 110/10 kV level voltage. The hardware part of the feeder monitoring system allows implementing the determination of feeder with fault and the phase of this feeder with fault without the need to switch off of the feeders. The software part of the system allows for ongoing monitoring of feeders with built-in alarm and viewing the event archive on the supervisor computer.

scholarly journals The Role of Fault Quotient in Determination of the Distance to a Transmission Line Fault

2008 ◽  
Vol 45 (5) ◽  
pp. 3-16
Author(s):  
J. Survilo
Keyword(s):  
Transmission Line ◽  
Single Phase ◽  
Power Lines ◽  
Impedance Method ◽  
Fault Current ◽  
Absolute Value ◽  
Fault Resistance ◽  
The Difference

The Role of Fault Quotient in Determination of the Distance to a Transmission Line Fault The notion of fault quotient refers to single-phase-earth and phase-to-phase faults in one-terminal and two-terminal (double fed), single or parallel power lines at determination of the distance to a fault place using the apparent impedance method. The fault quotient is determined as the ratio of the current through a fault place (fault current) to the current in a faulty phase at single-phase-earth faults and to the difference of currents in faulty phases at phase-to-phase faults. For one-terminal lines at single-phase-earth faults, neglecting capacitive and load currents, this ratio is 1, and for phase-to-phase faults it equals 1/2. For other cases it is a complex quantity, with the absolute value > 1 for single-phase-earth faults. Its significance grows with the fault resistance Rf. At Rf = 0 this ratio loses its significance for determination of the distance to a fault place. The tangent of the fault quotient angle with a real axis enters into the ultimate expressions for the reactance to fault place and for the fault resistance. The use of such a quotient facilitates reiterative calculations of the distance to a fault place.

scholarly journals Rating of amplitudes of high harmonics in determining feeder with single-phase ground fault

2020 ◽  
Vol 22 (1) ◽  
pp. 58-68 ◽  
Author(s):  
A. I. Fedotov ◽  
L. V. Akhmetvaleeva ◽  
R. S. Basyrov ◽  
G. V. Vagapov ◽  
E. A. Fedotov
Keyword(s):  
Single Phase ◽  
Field Experiments ◽  
Spectral Composition ◽  
Ground Fault ◽  
Neutral Mode ◽  
Ground Faults ◽  
Harmonic Components ◽  
Isolated Neutral ◽  
Comparison Of The Results ◽  
Selection Of

The aim of the paper is theoretical and experimental research of processes during the single-phase ground faults in electrical distribution grids of 10/06/35 kV with isolated neutral mode. The mathematical method of rationing is used for the analysis of the spectral composition of currents and voltages increasing the information content of the allocated higher harmonics of current and voltage. The paper show a comparison of the results of spectral analysis with and without taking into account the mathematical rationing obtained on the simulation model. Field experiments have demonstrated the effectiveness of using of the method of mathematical rationing of the higher harmonic components of current and voltage for various types of single-phase ground faults. The results of field experiments provided an opportunity of improving the methodology of yearling detection of single-phase ground faults in electric grids of 6-10-35 kV with an isolated mode of neutral. The conclusion of the research is the possibility of a significantly more accurate selection of the resonant frequencies of the spectrum of currents and voltages obtained by using of the method of mathematical rationing. The possibility of earlier and more precise localization of the feeder with ground fault is shown on the base more precise selection of the resonant frequency currents and voltages.

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