scholarly journals Research of the possibility of application of the superposition method for implementation of algorithms for determining damage locations in networks with isolated neutral

2020 ◽  
Vol 216 ◽  
pp. 01033
Author(s):  
A.L. Kulikov ◽  
V.Ju Osokin ◽  
D.I. Bezdushniy ◽  
A.A. Loskutov
Keyword(s):  
Simulation Modeling ◽  
Fault Location ◽  
Single Phase ◽  
Superposition Method ◽  
Electrical Networks ◽  
Medium Voltage ◽  
Arbitrary Configuration ◽  
Isolated Neutral ◽  
Technical Solutions ◽  
Emergency Mode

It is difficult to develop precise algorithms for determining fault locations for single-phase and double earth faults due to the features of emergency modes in medium voltage networks of 6-35 kV. The arbitrary configuration of electrical networks complicates the development of universal fault locations algorithms and, as a rule, technical solutions are limited by the need to use one-way measurements of emergency mode parameters. The article discusses new topology independent fault location algorithms that involve the use of the superposition method. The application of the proposed algorithms is justified by the results of simulation modeling and will allow implementation of calculating the distance to the fault in networks with isolated neutral with high accuracy.

Application of the Superposition Method for Fault Location in Medium Voltage Networks

2021 ◽  
pp. 38-44
Author(s):  
Aleksandr L. KULIKOV ◽  
◽  
Vladislav Yu. OSOKIN ◽  
Dmitriy I. BEZDUSHNYY ◽  
Anton A. LOSKUTOV ◽  
...  
Keyword(s):  
Fault Location ◽  
Operating Conditions ◽  
Electrical Network ◽  
Superposition Method ◽  
Electrical Networks ◽  
Medium Voltage ◽  
Arbitrary Configuration ◽  
Time Expenditures ◽  
Technical Solutions ◽  
High Degree

Medium-voltage networks are characterized by a long length and high degree of wear. Isolation of a failed network section requires significant time expenditures, a circumstance that makes accurate and fast determination of the fault location a topical problem. In view of specific features of emergency modes in medium voltage networks, the development of precise algorithms for fault location in the case of single and double ground faults involves certain difficulties. The arbitrary configuration of electrical networks, specific neutral grounding conditions, and lack of the possibility to perform multilateral measurements of emergency parameters complicate the development of universal fault location algorithms. In addition, technical solutions are as a rule limited by the need of using one-sided measurements of emergency mode parameters. The considered algorithms for calculating the distance to the fault location involve the use of emergency and normal electric network mode parameters. The proposed algorithms are based on using the superposition method and do not depend on the electrical network topology; they make it possible to decrease the influence of the current distribution pattern in lines with branches, as well as the influence of the load operating conditions on the accuracy of calculating the distance to fault location. The application of the proposed algorithms is justified by the results of simulation and makes it possible to calculate the distance to the fault location in networks with insulated neutral with high accuracy.

scholarly journals Analysis of the Influence of the Insulation Parameters of Medium Voltage Electrical Networks and of the Petersen Coil on the Single-Phase-to-Ground Fault Current

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1330
Author(s):  
Dumitru Toader ◽  
Marian Greconici ◽  
Daniela Vesa ◽  
Maria Vintan ◽  
Claudiu Solea
Keyword(s):  
Fault Location ◽  
Single Phase ◽  
Analytical Calculation ◽  
Electrical Network ◽  
Fault Current ◽  
Electrical Networks ◽  
Medium Voltage ◽  
Ground Fault ◽  
Fault Currents ◽  
Petersen Coil

Settings of protection are essential to ensure the sensitivity and selectivity needed to detect defects. Making the correct settings requires the calculation of the fault currents with as little error as possible. Fault currents are influenced by the parameters of the electrical networks, including the state of the insulation and the Petersen coil, which changes during their operation electrical networks. This paper analyzes how the insulation parameters of medium voltage power lines, the parameters of the Petersen coil used to treat the neutral of the medium voltage electrical network and the value of the resistance at the fault location influence the fault current in the case of a single-phase fault. The large number of single-phase faults that occur in medium voltage electrical networks justifies this analysis. The symmetrical components method was used to calculate the fault current. The results obtained by calculation were verified experimentally by causing a single-phase-to-ground fault in a real medium voltage network. The paper presents the situations in which the analytical calculation of the single-phase-to-ground fault current can lead to inadmissibly large errors, even over 50%, but also the situations in which the errors fall below 3%.

scholarly journals Dynamic stability of the functioning of current earth fault directional protection in networks with isolated neutral

Vestnik IGEU ◽  
2019 ◽  
pp. 30-41
Author(s):  
Yu.D. Kutumov ◽  
V.V. Tyutikov ◽  
T.Yu. Shadrikova ◽  
V.A. Shuin
Keyword(s):  
Dynamic Stability ◽  
Electrical Networks ◽  
Medium Voltage ◽  
Earth Fault ◽  
Fault Protection ◽  
Zero Sequence ◽  
Protection Devices ◽  
High Dynamic ◽  
Isolated Neutral ◽  
Zero Sequence Voltage

In distribution 6–10 kV networks with an insulated neutral for earth fault protection, zero sequence current directional protection devices are commonly used. According to the operation data, the main disadvantage of such kind of protection is the possibility of their functioning failures in transient conditions with the most dangerous for network intermittent arc earth faults. It is known that most earth faults in 6–10 kV networks, primarily in the initial stage of insulation damage, have an intermittent arc. Operation failures of zero sequence current directional protection in case of arc faults reduce the operational reliability of the protected network and, as a result, the reliability of power supply to consumers. Nowadays, new developments of electrical power systems relay protection devices, including earth fault protection of medium voltage distribution electrical networks, are implemented only on a microprocessor base. Therefore, the selection and justification of the implementation principles of zero sequence current directional protection which can provide high dynamic stability of functioning is a relevant objective. When analyzing the dynamic stability of the functioning of zero sequence directional current protection, regarding the complexity of transients during intermittent arc earth faults in medium voltage electrical networks with an isolated neutral, the simulation in Matlab using SimPowerSystem and Simulink was carried out. This study focuses on transient currents and voltages as the main factor influencing dynamic stability of the functioning of zero sequence current directional protection. The impact of other factors, for example, the inaccuracies of the primary zero sequence current and voltage transducers, the scheme of formation of compared quantities, etc. was not taken into account in simulation models. The study has allowed determining the causes of possible functioning failures of digital current earth fault directional protection in dynamic operation modes. It has been shown that the usage of orthogonal components of fundamental frequency of zero sequence voltage and current in current directional protection devices eliminates the failure of their operation with any kind of arc earth faults. To ensure high dynamic stability of operation under the influence of transients during arc intermittent earth faults, current directional protection for this type of damage should be performed on the basis of monitoring the phase relationships of the fundamental frequency components of 50 Hz of zero sequence voltage and current, but not their full values.

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 Differential method for damage location determining in 10 kV distribution networks with isolated neutral

2019 ◽  
Vol 124 ◽  
pp. 01003
Author(s):  
V. Kozlov ◽  
E. Kirzhatskikh ◽  
R. Giniatullin
Keyword(s):  
Transmission Lines ◽  
Short Circuit ◽  
Distribution Networks ◽  
Differential Method ◽  
Medium Voltage ◽  
Damage Location ◽  
Damage Repair ◽  
Three Phase ◽  
Isolated Neutral ◽  
Emergency Mode

Half of the length of all transmission lines (TL) are medium voltage networks. Single-line-to-ground short circuit (SLGSC) in distribution networks is the most common type of damage, accounting up to 70% of all types of damage. Faults in damage repair leads to an overvoltage of two healthy phases, resulting in double shorts, two-, three-phase shorts, which contributes to consumers’ disconnection. Remote damage location (DL) determination in tree-type networks is considered to be the most relevant, since these networks are spread over large areas, crossing rivers, ravines, lakes, forests, etc. This paper presents a differential method for DL determining based on steady-state voltage of damaged phase frequency. Measuring the parameters of emergency mode at the beginning and at the ends of 10kV TL allows compact stand-alone sensors using without their synchronization.

Single Phase Earth Fault Location in the Medium Voltage Distribution Networks

2009 ◽  
Vol 25 (25) ◽  
pp. 13-18 ◽  
Author(s):  
Jevgēnijs Linčiks ◽  
Dzintars Baranovskis
Keyword(s):  
Fault Location ◽  
Single Phase ◽  
Distribution Networks ◽  
High Accuracy ◽  
Calculation Methods ◽  
Voltage Distribution ◽  
Medium Voltage ◽  
Earth Fault ◽  
Location Methods

Single Phase Earth Fault Location in the Medium Voltage Distribution NetworksThis paper gives a description of the single phase earth fault location methods in the medium voltage networks. The single phase earth fault location in the medium voltage distribution networks is problematic now. The technical devices which are using in Latvia now do not allow to detect the single phase earth faults fast and high accuracy. Fast earth fault location should be possible by using the equipments which are calculating distance to earth faults. But precisely calculate the distance to the single phase earth faults in the medium voltage networks is very difficult. The paper presents the single earth fault location methods including the calculation methods for fault distance.

scholarly journals Improving the functioning efficiency of 6-10 kV electrical networks with isolated neutral in conditions of single-phase ground faults

2021 ◽  
Vol 288 ◽  
pp. 01010
Author(s):  
Alexander Nikolaevich Kachanov ◽  
Vadim Alekseevich Chernyshov ◽  
Boris Nikolaevich Meshkov ◽  
Marsel Sharifyanovich Garifullin ◽  
Evgeny Alexandrovich Pechagin
Keyword(s):  
Single Phase ◽  
Climatic Factors ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Distribution Networks ◽  
Electrical Network ◽  
Electrical Safety ◽  
Electrical Networks ◽  
Isolated Neutral ◽  
Remote Identification

The main objectives of this publication are: 1) to attract the attention of energy specialists to the problems of reliability and electrical safety of 6-10 kV overhead electrical networks with isolated neutral, operating in conditions of single-phase insulation damage; 2) substantiation of the feasibility of introducing a fundamentally new way to improve the efficiency of 6-10 kV distribution networks, based on the resonanceless limitation of the single-phase ground fault current arising from the breakdown of the insulator and the use of its own infrastructure of the electrical network for remote identification of the place of its occurrence. The expediency of including a nonlinear surge suppressor between the traverse and the grounding outlet of the reinforced concrete support is confirmed by the positive results of experimental studies carried out on the basis of high-voltage testing laboratories of IDGC of Center PJSC - Orelenergo and EnerGarant LLC. The use of deductive analysis allowed the authors to select a reliable and affordable electrical insulating material installed between the support and the traverse, as well as to formulate the main requirements for it, including taking into account weather and climatic factors. The analysis of various methods of transmitting information about the place of occurrence of the insulator damage made it possible to establish the predominant advantage of a wired communication channel using its own 6-10 kV electric network infrastructure. The authors have developed an original circuitry solution that provides remote identification of the insulator damage location using a thyristor shunting the nonlinear surge suppressor, according to a given switching algorithm, and also provides local identification of the insulator breakdown by means of special signaling devices with volatile power supply. It is expected that the proposed method, with relatively low investment, will significantly reduce the level of accidents and electrical hazards in overhead distribution networks of 6-10 kV, as well as minimize the costs associated with their operation and undersupply of electrical energy.

scholarly journals Earth Fault Location Using Negative Sequence Currents

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3759 ◽  
Author(s):  
Farughian ◽  
Kumpulainen ◽  
Kauhaniemi
Keyword(s):  
Fault Location ◽  
Single Phase ◽  
Distribution Networks ◽  
Practical Implementation ◽  
Negative Sequence ◽  
Medium Voltage ◽  
Different Types ◽  
Sequence Components ◽  
Zero Sequence ◽  
Negative Sequence Current

In this paper, a new method for locating single-phase earth faults on non-effectively earthed medium voltage distribution networks is proposed. The method requires only current measurements and is based on the analysis of the negative sequence components of the currents measured at secondary substations along medium voltage (MV) distribution feeders. The theory behind the proposed method is discussed in depth. The proposed method is examined by simulations, which are carried out for different types of networks. The results validate the effectiveness of the method in locating single-phase earth faults. In addition, some aspects of practical implementation are discussed. A brief comparative analysis is conducted between the behaviors of negative and zero sequence currents along a faulty feeder. The results reveal a considerably higher stability level of the negative sequence current over that of the zero sequence current.

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