scholarly journals Fault line selection research of single phase grounding circuit based on improved Hilbert-Huang transform

2021 ◽  
Vol 70 (11&12) ◽  
pp. 178
Author(s):  
Wenhong Li ◽  
Cong Wang ◽  
Shan Zhang ◽  
Mingjun Xu
Keyword(s):  
Single Phase ◽  
Real Data ◽  
Natural Oscillation ◽  
Opposite Polarity ◽  
Fault Line ◽  
Hilbert Huang Transform ◽  
Ground Fault ◽  
Mode Decomposition ◽  
Zero Sequence ◽  
Selection Research

For single-phase ground fault in resonant grounded power supply system, it is difficult to detect the fault line, while the existing methods have the shortcomings such as slow speed and large amount of computation. In our work the system natural oscillation wave contained in the zero sequence current is found to have opposite polarity and greater amplitude in fault line compared to that in non-fault line, and is proved to have a corresponding relationship with the first intrinsic mode function (IMF1) extracted from the same zero sequence current by empirical mode decomposition (EMD) of (Hilbert-Huang transform (HHT). Therefore, a new method for determining the single-phase ground fault line is proposed by finding the IMF1, extracted from the zero sequence current of each line by EMD of HHT, with the largest amplitude and opposite polarity compared to that of other lines. Meanwhile, EMD algorithm is improved to further enhance the fault detection rate based on the system natural oscillation wave’s frequency and its attenuation trend in resonant grounding system. Simulation experiment and real data analysis indicate that the mentioned method is correct and fast.

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.

scholarly journals Single-phase-to-ground Fault Line Selection Method Based on STOA-SVM

2021 ◽  
Vol 2095 (1) ◽  
pp. 012029
Author(s):  
Yicen Liu ◽  
Xiaojiang Liu ◽  
Songhai Fan ◽  
Xiaomin Ma ◽  
Sijing Deng
Keyword(s):  
Single Phase ◽  
Distribution Network ◽  
Ensemble Empirical Mode Decomposition ◽  
Selection Method ◽  
Support Vector ◽  
Ground Fault ◽  
Mode Decomposition ◽  
Before And After ◽  
Zero Sequence ◽  
Line Selection

Abstract In view of the complex characteristics of nonlinearity and non-stableness of the zero-order current of each line after the single-phase ground fault of the distribution network, a distribution network fault selection method based on Sooty Tern Optimization Algorithm(STOA) and the combination of support vector machine is proposed. At first, the zero-sequence current before and after fault is obtained, then five kinds of IMFs including different components are obtained by ensemble empirical mode decomposition, and the energy entropy of the fault transient zero-sequence current is obtained by Hilbert transform, the results of training and testing are obtained by inputting the feature vector. The simulation results show that the accuracy of the proposed line selection model is 97.5%.

The Research Based on Zero Sequence Energy to the Line Selection in Distribution Network

2012 ◽  
Vol 614-615 ◽  
pp. 846-849
Author(s):  
Shu Tian ◽  
Jin Peng He ◽  
Yu Zheng
Keyword(s):  
Single Phase ◽  
Distribution Network ◽  
Power Network ◽  
Fault Line ◽  
Ground Fault ◽  
Arc Suppression Coil ◽  
Zero Sequence ◽  
Line Selection ◽  
Fault Lines ◽  
Resistance Component

When single phase-to-ground fault happened in power network with arc suppression coil grounded, capacitor current through fault point is compensated and reduced by installing arc suppression coil. Zero-sequence current’s amplitude and phase of fault lines and sound lines are so similar that it increases the difficulty of selecting the fault line. But the resistance component of zero sequence current has no relationship with the arc extinguishing coil compensation, absolute value of resistance component to the fault lines show the maximum, and zero sequence current’s polarity of fault lines is contrary to sound lines. In this paper, because of the characteristic of resistance component, a method is put forward based on zero sequence energy to the line selection in distribution network, it import auto-reclosing techniques into the line selection. The principle is verified by MATLAB simulator. It has high accuracy to select the fault line with this method.

Methods of Getting Zero Sequence Current in a Single-Phase-to-Ground Fault

2012 ◽  
Vol 614-615 ◽  
pp. 891-894
Author(s):  
Yu Xia Li
Keyword(s):  
Single Phase ◽  
Current Transformer ◽  
Fault Line ◽  
Current Transformers ◽  
Ground Fault ◽  
Electronic Current ◽  
Digital Substation ◽  
Current Transducer ◽  
Zero Sequence ◽  
The Common

After a single-phase-to ground fault, fault voltage and current information should be sampled accurately for automatic equipments to detect the fault line. And zero sequence current is the very key element to detect the fault line after an earth fault happens. The widely used methods of getting zero sequence current are in details described. The common methods are by zoro sequence current transformers, by wye connections of three CTs, and by zero-sequence current transducer. A new method by magnetic field induction and the structure of magnetic induction device are introduced, as well as a new way by electronic current transformer and its application in digital substation.

Fault Line Selection in Resonant Grounded System Based on IMEn

2014 ◽  
Vol 960-961 ◽  
pp. 755-758
Author(s):  
Meng Zhang ◽  
Jian Wen Ren
Keyword(s):  
Empirical Mode Decomposition ◽  
Signal Analysis ◽  
Single Phase ◽  
Sample Entropy ◽  
Fault Current ◽  
Fault Line ◽  
Fault Line Selection ◽  
Ground Fault ◽  
Mode Decomposition ◽  
Line Selection

When the single phase ground fault occurs in resonant grounded system, there are significant differences in the components of fault phase current between fault line and non-fault line. This feature can be reflected by intrinsic mode entropy (IMEn) of fault current. IMEn is a new signal analysis over multiple oscillation levels. It corresponds to the sample entropy (SampEn) and the empirical mode decomposition (EMD). The results of fault simulations in different conditions indicate that the method is reliable.

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.

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