Increase Effectiveness Functioning of Protection against Single-Phase Ground Fault Electrical Networks Medium Voltage

2020 ◽  
Author(s):  
Denis N. Pelenev ◽  
Boris N. Abramovich ◽  
Kirill V. Babyr
Keyword(s):  
Single Phase ◽  
Electrical Networks ◽  
Medium Voltage ◽  
Ground Fault

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 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 Analysis of Overvoltages Appearing in One-Sidedly Ungrounded MV Power Cable Screen

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1821 ◽  
Author(s):  
Aleksandra Schött-Szymczak ◽  
Krzysztof Walczak
Keyword(s):  
Single Phase ◽  
Field Studies ◽  
Power Cable ◽  
Cable Line ◽  
Medium Voltage ◽  
Ground Fault ◽  
Actual Outcome ◽  
Connection Type ◽  
Overvoltage Protection ◽  
Line Work

Changing the connection type of a medium voltage (MV) cable screen is linked to a decrease in power loss, although it may also lead to the generation of overvoltage in a metallic cable screen, which is hazardous for proper cable line work. In this paper, results of simulation and field researches are presented, showing the range of voltages that occurs in cable screens during single-phase ground fault. There are considered to be three scenarios according to the applied type of cable screen connection. Conducted researches allow the comparison of chosen methods of simulation with an actual outcome. Results obtained during simulation and field studies lead to the conclusion that the range of overvoltage occurred in a cable screen could in fact be dangerous for the cable line’s sheath insulation without proper overvoltage protection.

A Survey on Single-Phase Faulty Line Selection Techniques for Small Current Grounding System in Medium-Voltage Grid

2014 ◽  
Vol 492 ◽  
pp. 407-411 ◽  
Author(s):  
Yin Tao ◽  
Yu Juan
Keyword(s):  
Single Phase ◽  
Development Trend ◽  
Small Current ◽  
Simulation Research ◽  
Grounding System ◽  
Medium Voltage ◽  
Fault Line Selection ◽  
Ground Fault ◽  
Line Selection ◽  
The Development Trend

Single-phase ground fault line selection problem has never been satisfactorily resolved in small current neutral grounding system in china. According to such a situation and combining theoretical analysis and simulation research with reports published in literature, existing faulty line selection technologies are generalized, and working principles, application conditions and existing defects of these technologies are analyzed, meanwhile the feasible improvement of these technologies and the up-to-date research achievements, and deficiencies of applications in this field are summarized. Finally, the development trend of faulty line selection technology for small-current neutral grounding system is pointed out.

Design and Implementation of Wireless Voltage Monitoring System Based on Zigbee

2017 ◽  
Vol 12 (3) ◽  
pp. 83-96 ◽  
Author(s):  
Luo Xiaohui
Keyword(s):  
Monitoring System ◽  
Single Phase ◽  
Low Cost ◽  
Moving Average ◽  
Voltage Sensor ◽  
Wireless Transmission ◽  
Phase Voltage ◽  
Medium Voltage ◽  
Wireless Monitoring ◽  
Three Phase

This paper proposed a low cost wireless monitoring system based on ZigBee wireless transmission, and designed a new floating voltage sensor which is suitable for the monitoring of medium voltage and high voltage(MV/HV) public equipment. The system used TI-CC2530 as the controller, proposed a new moving average voltage sensing(MAVS) algorithm by reasonable assumptions, and adopted algorithms to perform the theoretical analysis for the single phase and three-phase voltage. At last, the author carried out a practical experiment on the wireless floating voltage sensor under the voltage up to 30kV, the experimental results showed that the proposed low cost wireless sensor can achieve a good voltage monitoring function, and the error is less than 3%.

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