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.

scholarly journals Non-Directional Earth Fault Passage Indication in Isolated Neutral Distribution Networks

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4732
Author(s):  
Amir Farughian ◽  
Lauri Kumpulainen ◽  
Kimmo Kauhaniemi
Keyword(s):  
Single Phase ◽  
Distribution Networks ◽  
Voltage Measurement ◽  
Negative Sequence ◽  
Overhead Lines ◽  
New Methods ◽  
Zero Sequence ◽  
Isolated Neutral ◽  
Negative Sequence Current ◽  
Symmetrical Sequence

In this paper, two new methods for locating single-phase to ground faults in isolated neutral distribution networks are proposed. The methods are based on the analysis of symmetrical sequence currents. They are solely based on currents, not requiring voltage measurement. The first method employs only the zero sequence current and the second one utilizes the negative sequence current in combination with the zero sequence current. It is revealed why using only zero sequence current with a simple threshold is insufficient and may lead to false results. Using the proposed methods, earth faults with high resistances can be located in isolated neutral distribution networks with overhead lines or cables.

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 On the Use of LoRa Technology for Logic Selectivity in MV Distribution Networks

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3079 ◽  
Author(s):  
Leopoldo Angrisani ◽  
Francesco Bonavolontà ◽  
Annalisa Liccardo ◽  
Rosario Schiano Lo Moriello
Keyword(s):  
Cost Effectiveness ◽  
Long Range ◽  
Distribution Networks ◽  
Fault Isolation ◽  
Optimized Design ◽  
Medium Voltage ◽  
Different Types ◽  
The Times ◽  
The Cost ◽  
Types Of Faults

In this paper, a logic selectivity system based on Long Range (LoRa) technology for the protection of medium-voltage (MV) networks is proposed. The development of relays that communicate with each other using LoRa allows for the combination of the cost-effectiveness and ease of installation of wireless networks with long-range coverage and reliability. The realized demonstrator to assess the proposed system is also presented in the paper; based on different types of faults and different locations, the times needed for clearing a fault and restoring the network were estimated from repeated experiments. The obtained results confirm that, with an optimized design of transmitted packets and of protocol characteristics, LoRa communication grants fault management that meets the criteria of logic selectivity, with fault isolation occurring within the maximum allowed time.

scholarly journals Modeling of three-phase electric motor operation by the MATLAB system with deteriorated power quality in the 0.38 kV distribution networks

2018 ◽  
Vol 58 ◽  
pp. 03016 ◽  
Author(s):  
I.V Naumov ◽  
N.V. Savina ◽  
M.V. Shevchenko
Keyword(s):  
Induction Motor ◽  
Power Quality ◽  
Electric Motor ◽  
Distribution Networks ◽  
Negative Sequence ◽  
Operation Modes ◽  
Three Phase ◽  
Sequence Components ◽  
Motor Operation ◽  
The Impact

One of the main operation modes that characterizes power quality in distribution networks is asymmetry of three-phase voltage system. Operation of an induction motor (IM) with disturbed voltage symmetry in the supply network can not be considered as a rated one. The system of voltages applied to the stator winding of IM under these conditions contains positive- and negative-sequence components. This worsens the performance characteristics of IM essentially. In order to balance the 0.38 kV network operation and enhance the efficiency of the three-phase electric motor operation it is suggested to use a special balancing unit (BU) that minimizes the negative-sequence components of current and voltage. The operation modes of the obtained system “supply source – induction motor – balancing unit” are simulated within the MATLAB software package of applied programs, which allows one to assess the impact of low quality of power on the operating characteristics of the electric motor and the efficiency of the balancing unit to increase the “durability” of the motor under the asymmetrical power consumption.

Research on Electrical Characteristics of a Novel Balance Transformer with Asymmetrical Winding

2014 ◽  
Vol 536-537 ◽  
pp. 1523-1526 ◽  
Author(s):  
Yong Sheng Li ◽  
Yi Fa Sheng ◽  
Kai Yi Zhang ◽  
Bo Fan
Keyword(s):  
Magnetic Force ◽  
Short Circuit ◽  
Neutral Current ◽  
Force Balance ◽  
Analysis Method ◽  
Systematic Analysis ◽  
Negative Sequence ◽  
Transfer Equations ◽  
Zero Sequence ◽  
Negative Sequence Current

For problems of zero sequence current and negative sequence current of traction transformer in Electrified Railway, a novel balance transformer with asymmetrical windings was presented. By a systematic analysis method based on the magnetic force balance equations, winding connection equations, output-port equations and voltage transfer equations, the current relationships of the primary windings and secondary windings, the balance condition and the short circuit impedances (when the neutral current in the primary side is zero) were deduced, and the electric characteristics of the balance transformer was analyzed. Through the experimental model of balance transformer in simulation platform based on Matlab/Simulink, the electric characteristics of balance transformer and change law of zero sequence current and negative sequence current in different mode were researched. Correctness and feasibility of the theoretical analysis are verified through the simulation experiment.

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.

scholarly journals Determining single-phase earth fault location with applying short-term double earth fault

2019 ◽  
Vol 139 ◽  
pp. 01041
Author(s):  
A.L. Kulikov ◽  
V.Ju. Osokin ◽  
D.I. Bezdushniy
Keyword(s):  
Fault Location ◽  
Single Phase ◽  
Distribution Networks ◽  
Accurate Solution ◽  
Accurate Calculation ◽  
Short Term ◽  
Earth Fault ◽  
Predominant Type ◽  
The Future ◽  
Artificial Introduction

The single-phase earth faults location are the predominant type of damage in distribution networks of 6-35 kV. The problem of remotely determining the fault location during single-phase earth faults has not definitely accepted practical and accurate solution. The article proposes and substantiates the intellectual methods of determining the fault location with using artificial introduction of short-term double earth faults. In the future by recorded oscillograms of currents and voltages, an accurate calculation of the distance to the damage is assumed.

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