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

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.

2012 ◽  
Vol 614-615 ◽  
pp. 846-849
Author(s):  
Shu Tian ◽  
Jin Peng He ◽  
Yu Zheng

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.


2012 ◽  
Vol 482-484 ◽  
pp. 2197-2203 ◽  
Author(s):  
Fang Peng ◽  
Yu Shen Zhou ◽  
Yong Feng Liu ◽  
An Hui Yuan ◽  
Lei Zhu

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.


2013 ◽  
Vol 340 ◽  
pp. 445-450
Author(s):  
Jun Ying Zhao ◽  
Xing He Ma ◽  
Bing Yao Yan

In order to solve the high-voltage grid electricity coal mine one-phase ground fault (high leak), choose the theory of fuzzy algorithm. According to the current harmonic fault diagnostic, zero sequence active power method and transient zero sequence current mutual product summation method, three methods set fault measure membership function and weight coefficient membership function, realize fuzzy comprehensive decision, judge single-phase grounding line. Through the Matlab/Simulink simulation experiment, fuzzy theory algorithm can accurately choose single-phase grounding line.


2013 ◽  
Vol 340 ◽  
pp. 572-577 ◽  
Author(s):  
Xiao Wei Wang ◽  
Yu Jun Zhang ◽  
Ya Xiao Hou

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.


2021 ◽  
Vol 2095 (1) ◽  
pp. 012029
Author(s):  
Yicen Liu ◽  
Xiaojiang Liu ◽  
Songhai Fan ◽  
Xiaomin Ma ◽  
Sijing Deng

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%.


2013 ◽  
Vol 805-806 ◽  
pp. 673-677
Author(s):  
Feng Xiang Dong ◽  
Chao Guo Tang ◽  
Zheng Yuan ◽  
Wen Hai Zhang

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.


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