scholarly journals An Improved Traveling-Wave-Based Fault Location Method with Compensating the Dispersion Effect of Traveling Wave in Wavelet Domain

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Huibin Jia

The fault generated transient traveling waves are wide band signals which cover the whole frequency range. When the frequency characteristic of line parameters is considered, different frequency components of traveling wave will have different attenuation values and wave velocities, which is defined as the dispersion effect of traveling wave. Because of the dispersion effect, the rise or fall time of the wavefront becomes longer, which decreases the singularity of traveling wave and makes it difficult to determine the arrival time and velocity of traveling wave. Furthermore, the dispersion effect seriously affects the accuracy and reliability of fault location. In this paper, a novel double-ended fault location method has been proposed with compensating the dispersion effect of traveling wave in wavelet domain. From the propagation theory of traveling wave, a correction function is established within a certain limit band to compensate the dispersion effect of traveling wave. Based on the determined arrival time and velocity of traveling wave, the fault distance can be calculated precisely by utilizing the proposed method. The simulation experiments have been carried out in ATP/EMTP software, and simulation results demonstrate that, compared with the traditional traveling-wave fault location methods, the proposed method can significantly improve the accuracy of fault location. Moreover, the proposed method is insensitive to different fault conditions, and it is adaptive to both transposed and untransposed transmission lines well.

Author(s):  
Congshan Li ◽  
Ping He ◽  
Feng Wang ◽  
Cunxiang Yang ◽  
Yukun Tao ◽  
...  

Background: A novel fault location method of HVDC transmission line based on a concentric relaxation principle is proposed in this paper. Methods: Due to the different position of fault, the instantaneous energy measured from rectifier and inverter are different, and the ratio k between them is the relationship to the fault location d. Through the analysis of amplitude-frequency characteristics, we found that the wave attenuation characteristic of low frequency in the traveling wave is stable, and the amplitude of energy is larger, so we get the instantaneous energy ratio by using the low-frequency data. By using the method of wavelet packet decomposition, the voltage traveling wave signal was decomposed. Results: Finally, calculate the value k. By using the data fitting, the relative function of k and d can be got, that is the fault location function. Conclusion: After an exhaustive evaluation process considering different fault locations, fault resistances, and noise on the unipolar DC transmission system, four-machine two-area AC/DC parallel system, and an actual complex grid, the method presented here showed a very accurate and robust behavior.


Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2066 ◽  
Author(s):  
Shimin Xue ◽  
Junchi Lu ◽  
Chong Liu ◽  
Yabing Sun ◽  
Baibing Liu ◽  
...  

Accurate and reliable fault location method for alternating current (AC) transmission lines is essential to the fault recovery. MMC-based converter brings exclusive non-linear characteristics to AC networks under single-phase-to-ground faults, thus influencing the performance of the fault location method. Fault characteristics are related to the control strategies of the converter. However, the existing fault location methods do not take the control strategies into account, with further study being required to solve this problem. The influence of the control strategies to the fault compound sequence network is analyzed in this paper first. Then, a unique boundary condition that the fault voltage and negative-sequence fault current merely meet the direct proportion linear relationship at the fault point, is derived. Based on these, a unary linear regression analysis is performed, and the fault can be located according to the minimum residual sum function principle. The effectiveness of the proposed method is verified by PSCAD/EMTDC simulation platform. A large number of simulation results are used to verify the advantages on sampling frequency, fault resistance, and fault distance. More importantly, it provides a higher ranging precision and has extensive applicability.


2020 ◽  
Author(s):  
Gustavo A. Cunha ◽  
Felipe V. Lopes ◽  
Tiago H. Honorato

Traveling wave-based fault location has attracted more and more attention from industries worldwide. This theory allowed the implementation of functions in order to increase the reliability of the obtained fault location results. Among existing functions, the classical one-terminal method requires the detection of the wave reflected from the fault, which is still considered a challenging task. A commercial relay was released with a function able to identify these reflected waves by evaluating patterns and weighted hypotheses, identifying the wavefront most likely to be the one re ected from the fault. However, as this function is embedded into a relay, it is not possible to change the method settings. Thus, this paper presents a validation of this function which is implemented externally to the relay. Besides, its application is extended for transmission lines to which the relay can not be applied, such as huge HVDC lines.


2014 ◽  
Vol 556-562 ◽  
pp. 2723-2727 ◽  
Author(s):  
Lu Hua Xing ◽  
Qing Chen ◽  
Bing Lei Xue

A fault location method for HVDC (High Voltage Direct Current) transmission lines is proposed in this paper, using voltages and currents measured at two terminals of dc lines in time domain. Fault traveling waves propagate from the fault point to both terminals along the faulted line. The position that the traveling wave head arrives at some moment after the fault can be used to calculate the fault location. To determine the arrival positions of traveling wave head at each time indirectly, propagation characteristic curves of traveling wave heads at local and the remote terminals are calculated with distribution currents using the stationary wavelet transform. The accuracy of fault location will not be affected by transition resistance and fault position. Simulation results show that the presented fault location method can achieve quick and accurate fault location on the whole line under probable operation modes of a bipolar HVDC transmission system.


2014 ◽  
Vol 1003 ◽  
pp. 124-129
Author(s):  
Jian Xu Lu ◽  
Cheng Jia Ma

Among the available fault location methods based on traveling waves, calibrations of wave velocity and wave arrival time are the two main problems. This paper proposes a new fault location method which combines the two problems mentioned above. In this method, the first wave and second wave obtained at one side and the first wave obtained at the other side is used to locate the fault point. And the Hilbert-Huang transform is used in the calibration of wave arrival time, making the method more accurate than using wavelet transform. This method has the following two advantages: At first, it dismisses the influence of wave velocity. In the second, it doesn’t need to distinguish the sources of the received waves. ATP-EMTP’s simulation results show that this method is available and the location precision is higher than traditional fault location methods.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xiao-Wei Liu

After a transmission line fails, quickly and accurately find the fault point and deal with it, which is of great significance to maintaining the normal operation of the power system. Aiming at the problems of low accuracy of traditional traveling wave fault location methods and many affected factors, this paper relies on distributed traveling wave monitoring points arranged on transmission lines to study methods to improve the accuracy of traveling wave fault location on transmission lines. First, when a line fails, a traveling wave signal that moves to both ends will be generated and transmitted along the transmission line. We use the Radon transform algorithm to process the traveling wave signal. Then, this paper uses ant colony algorithm to analyze and verify the location and extent of transmission line faults and then optimizes high-precision collection and processing. Finally, the simulation distance measurement is carried out on double-terminal transmission lines and multiterminal transmission lines (T-shaped lines) with branches. The results show that, for double-ended transmission lines, the algorithm increases the speed of matrix calculations and at the same time makes the fault location error of the transmission grid still maintain the improved effect.


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