A new method for fault line selection based on correlation between zero-sequence voltage in bus and zero-sequence current in feeders

2015 ◽  
Author(s):  
Yunkun Xiang ◽  
Yun Jiang ◽  
Yuanzhi Ning ◽  
Fang Tao ◽  
Bohan Liu
Keyword(s):  
New Method ◽  
Fault Line ◽  
Fault Line Selection ◽  
Zero Sequence ◽  
Line Selection ◽  
Zero Sequence Voltage

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.

Fault Line Selection in Distribution Networks Based on Parameter Identification in Frequency Domain

2013 ◽  
Vol 325-326 ◽  
pp. 643-646
Author(s):  
Jia Le Suonan ◽  
Zong Peng Li
Keyword(s):  
Parameter Identification ◽  
Frequency Domain ◽  
Frequency Band ◽  
New Method ◽  
Neutral System ◽  
Fault Line ◽  
Fault Line Selection ◽  
Zero Sequence ◽  
Line Selection ◽  
The Impact

The distribution network is mostly the ungrounded neutral system or the resonant grounded system in many countries. Selecting the fault line as soon as possible is of great significance to power systems. This paper proposes a parameter identification method in frequency domain to solve this problem. By using the matrix pencil method to extract frequency-points and their information in zero-sequence voltage and zero-sequence current, spectral leakage in DFT is avoided. With the estimated frequency points, an equation in frequency domain is established which will help to calculate the capacitance value and thus to identify the fault line. This method requires a low sampling rate and has high accuracy. In addition, the frequency-band in this new method is wider than the SFB's frequency-band. Verified by simulation in ATP-EMTP and data from RTDS, the new method is quite effective in fault line selection with an ability to overcome transition resistor and is immune from the impact of arc-suppression.

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.

scholarly journals Optimal Denoising and Feature Extraction Methods Using Modified CEEMD Combined with Duffing System and Their Applications in Fault Line Selection of Non-Solid-Earthed Network

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 536 ◽  
Author(s):  
Sizu Hou ◽  
Wei Guo
Keyword(s):  
Noise Reduction ◽  
Empirical Mode Decomposition ◽  
Ensemble Empirical Mode Decomposition ◽  
Fault Line ◽  
Fault Line Selection ◽  
Duffing System ◽  
Mode Decomposition ◽  
Force Signal ◽  
Zero Sequence ◽  
Line Selection

As the non-solid-earthed network fails, the zero-sequence current of each line is highly non-stationary, and the noise component is serious. This paper proposes a fault line selection method based on modified complementary ensemble empirical mode decomposition (MCEEMD) and the Duffing system. Here, based on generalized composite multiscale permutation entropy (GCMPE) and support vector machine (SVM) for signal randomness detection, the complementary ensemble empirical mode decomposition is modified. The MCEEMD algorithm has good adaptability, and it can restrain the modal aliasing of empirical mode decomposition (EMD) at a certain level. The Duffing system is highly sensitive when the frequency of the external force signal is the same as that of the internal force signal. For automatically identifying chaotic characteristics, by using the texture features of the phase diagram, the method can quickly obtain the numerical criterion of the chaotic nature. Firstly, the zero-sequence current is decomposed into a series of intrinsic mode functions (IMF) to complete the first noise-reduction. Then an optimized smooth denoising model is established to select optimal IMF for signal reconstruction, which can complete the second noise-reduction. Finally, the reconstructed signal is put into the Duffing system. The trisection symmetry phase estimation is used to determine the relative phase of the detection signal. The faulty line in the non-solid-earthed network is selected with the diagram outputted by the Duffing system.

Feasibility Study on the Fault Line Selection Method Based on Overall Trend of Zero Sequence Current

2013 ◽  
Vol 341-342 ◽  
pp. 1235-1238
Author(s):  
Li Gao ◽  
Hong Chun Shu
Keyword(s):  
Phase Angle ◽  
Direct Current ◽  
Initial Phase ◽  
Travelling Wave ◽  
Current Component ◽  
Fault Line ◽  
Preliminary Stage ◽  
Fault Line Selection ◽  
Zero Sequence ◽  
Line Selection

Two results were obtained by analysing electromagnetism transition condition: firstly, when the initial phase angle of fault is larger, the characteristic of travelling wave is obvious, and the polarity of the first travelling wave head is consistent with the overall trend of zero sequence current in preliminary stage; secondly, when the initial phase angle of fault is smaller, the characteristic of travelling wave is not obvious, but the fault lines and perfect lines can be recognized through the direction of decaying direct current component in zero sequence current, and the direction of decaying direct current component is consistent with the overall trend of zero sequence current in preliminary stage. Research suggests that it is feasible to make the overall trend of zero sequence current in preliminary stage as characteristic for line selection.

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