The Identification of Single-Line-to-Ground Fault in Neutral Un-Effectively Earthed System

2013 ◽  
Vol 805-806 ◽  
pp. 673-677
Author(s):  
Feng Xiang Dong ◽  
Chao Guo Tang ◽  
Zheng Yuan ◽  
Wen Hai Zhang
Keyword(s):  
Traditional Method ◽  
Single Line ◽  
Fault Line ◽  
Fault Line Selection ◽  
High Impedance ◽  
Ground Fault ◽  
Large Numbers ◽  
Zero Sequence ◽  
Line Selection ◽  
Zero Sequence Voltage

The correct and reliable identification of SLG(single-line-to-ground) fault is the foundation of starting the fault line selection and location device in neutral un-effectively earthed system. The traditional method based on the zero sequence voltage is invalid when the fault happens with high impedance, because the zero sequence voltage in bus is small. So a new algorithm based on the variation of voltage including the zero sequence voltage and phase voltages is proposed. The algorithm is not affected by the unbalance of system, and the sensitivity and the reliability of the algorithm are considered simultaneously. The algorithm is proved effectively by the large numbers of simulations using PSCAD/EMTDC program.

Line Selection Analysis of Ground Fault in Distribution Network Based on Chief Half-Wave and Remnant Current

2012 ◽  
Vol 482-484 ◽  
pp. 2197-2203 ◽  
Author(s):  
Fang Peng ◽  
Yu Shen Zhou ◽  
Yong Feng Liu ◽  
An Hui Yuan ◽  
Lei Zhu
Keyword(s):  
Distribution System ◽  
Single Phase ◽  
Neutral System ◽  
Selection Methods ◽  
Fault Line ◽  
Fault Line Selection ◽  
Ground Fault ◽  
Half Wave ◽  
Line Selection ◽  
Isolated Neutral

Abstract：This paper analyses characteristics of single-phase ground fault in distribution system. Now, most of the line selection methods have some limitations, which leads to the low accuracy of the fault line selection. In order to solve above problems, make use of the matlab software in this article to simulate and analyze the isolated neutral system and resonance neutral earthing system when they occur single-phase ground fault. Finally, the new method based on first half wave method and increment of residual current to improve the accuracy of fault line selection is proposed.

A New Detection Way for Single- Phase to Ground Fault Based on Energy Function Intergral and Wavelet Packets

2012 ◽  
Vol 217-219 ◽  
pp. 2629-2633 ◽  
Author(s):  
Yang Liu ◽  
Zhang Bao Chen ◽  
Lin Ye
Keyword(s):  
Single Phase ◽  
Integral Transform ◽  
Phase Distribution ◽  
Wavelet Packets ◽  
Fault Line ◽  
Line Energy ◽  
Ground Fault ◽  
Zero Sequence ◽  
Line Selection ◽  
Parallel Resistance

In order to find new fault line selection method of single-phase distribution network, First parallel resistance in the neutral point in order to increase the transient component of the fault line, obtained the line energy after the failure through the integral transform , initially selected probable fault lines , on this basis, decompose all the transient zero sequence currents in every line by separation based on nicer separate frequency characteristic of wavelet packets, to accurately determine the greatest fault line by the characteristic that the value of second singular point generated by zero sequence current is maximum and its polarity is opposite to the other normal lines, simulation results show the effectiveness and correctness of the method. So the method for detection of the fault line based on wavelet packets and the compare of energy is new and effective.

Fault Line Selection and Section Location of Distribution Network Based on S-Transform and Zero-Sequence Reactive Power

2013 ◽  
Vol 442 ◽  
pp. 176-182
Author(s):  
Nan Hua Yu ◽  
Rui Li ◽  
Hong Guang Cao ◽  
Wei Qing Tao ◽  
Chuan Jian Li
Keyword(s):  
Reactive Power ◽  
Fault Line ◽  
Fault Line Selection ◽  
S Transform ◽  
Transient Energy ◽  
Zero Sequence ◽  
Line Selection ◽  
The Difference ◽  
Main Station ◽  
Fault Information

An approach of fault line selection and section location based on S-Transform transient energy integrated with zero-sequence reactive direction is proposed. Fault information of zero-sequence currents collected by each feeder terminal unit (FTU) were uploaded to the main station on the use of real-time communication technologies,and then the main station take analysis for the whole network fault information, using S-transform to obtain the main characteristic frequency of the signal, then compare the transient energy and zero-sequence reactive direction of each feeder line of the frequency to achieve fault line selection. According to the difference of waveform in front and back of the fault point in the fault line,using this above method to realize section location. The simulations and analysis demonstrate the accuracy and reliability of this approach , and its not affected by fault close angle, noise and other factors.

A Novel Fault Line Selection Method of Distribution Network Based on Wavelet Packet Energy

2013 ◽  
Vol 340 ◽  
pp. 572-577 ◽  
Author(s):  
Xiao Wei Wang ◽  
Yu Jun Zhang ◽  
Ya Xiao Hou
Keyword(s):  
Wavelet Packet ◽  
Distribution Networks ◽  
Maximum Energy ◽  
Fault Line ◽  
Line Energy ◽  
Branch Line ◽  
Fault Line Selection ◽  
Zero Sequence ◽  
Line Selection ◽  
Base Band

This article introduces a novel fault line selecting method which is based on the wavelet packet energy. With the db10 wavelet packet decomposition of zero-sequence transient current signal of the fault branch line, it can eliminate the component of base band of reflecting the fundamental frequency. Based on this, it can get wavelet energy of the various branch line. If a line of energy is obvious superior in contrast with the other line energy, then it is the first decision for branch line fault. Secondly, it can give the possible fault line sorting according to the principle of from large to smalland start the circuit recluse to monitor the current of the order in sequence. While 3U0 is disappeared, then determining the fault line is the maximum energy lines. If not, then continuing to monitor energy big line until the fault line is selected. The simulation results show that the accuracy rate of the fault circuit selecting method is higher, it can be applied to the fault circuit selecting of cable mixed in distribution networks.

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