Traveling Wave Fault Location Research Articles

Waveform Recognition Technology in Distributed Fault Location of Transmission Line

Distributed way of traveling-wave fault location algorithm is a new theory founded in recent years. By installing sensing points in distributed way, the accuracy of fault location result can be clearly improved comparing to traditional methods. First, PSCAD is used to simulate the transmission line model and measure the three-phase current data. Second, by using wavelet transformation and phase to-module transformation, these current data is mathematically processed and modulus maximum is achieved easily. Finally, time difference between the adjacent modulus maximum points is calculated and the location is figured out by using the module time-difference algorithm. The test result shows that the method above is valid and the relative error is rather small.

A New Fault Location Method for 10 KV Distribution Lines with Branches

By using the advantages of C-type of traveling wave fault location method in distance measuring and the pattern recognition function of support vector machines (SVM),a new fault location method is presented.The first step of the method is determining the fault distance by C-type of traveling wave location method; the second one is locating the fault section by SVM. It also adopts the wavelet to reduce the noise of fault signal,and the accuracy can be more precise when the parameters of SVM are optimized.The simulation results of ATP and MATLAB show that the method can determine the single phase grounding fault point in 10kv distribution networks with branches accurately.

Wide area traveling wave based power grid fault network location method

Traditional fault traveling wave location schemes, which are based on the fault information of only one line, have lower sensitivity and reliability, especially when one or more traveling wave fault location devices (TWFLD) break down, startup fails or an incorrect arrival time of the initial traveling wave is recorded, this will result in the failure of the fault location. Based on the analysis of the propagation characteristics of the fault traveling wave in power grid, a novel power grid fault traveling wave network location method is proposed in this paper. Firstly, the topology of a power grid is analyzed, and the installation principle of TWFLD is presented. Secondly, when the fault occurs on one transmission line, the fault traveling waves travel from the fault point to the whole power grid, and the values of the arrival time of the initial traveling wave is recorded in the substations where the TWFLD are installed. Then the values of the arrival time are analyzed with the information fusion and the fault point is located by using the power grid fault traveling wave network location method. Compared to the existing fault traveling wave location schemes those are based on the fault information of only one line, all correct time information of the whole power grid has been used to calculate the fault distance in this method. Therefore, this method can achieve reliable fault location even when one or more TWFLD break down, startup fails or an incorrect arrival time of the initial traveling wave is recorded. The simulation results match the theoretical analysis well and show that the proposed location method provides not only high accuracy and reliability, but also good economy. These characteristics are beneficial to further enhancement of the practicability of the traveling wave location.

An Approach of Wavefront Identification for Traveling Wave Fault Location Based on Harris Corner Detector

Wavefront identification is important for traveling based fault location. In order to improve its reliability, a novel wavefront identification method based on Harris corner detector has been proposed in this paper. The principle of single-ended traveling wave fault location was briefly introduced at first, and the features of wavefronts generated by faults on transmission lines were analyzed. The arrival of traveling waves' wavefronts is considered as corner points in digital image of waveshape. The corner points can be extracted precisely by Harris corner detector, and both false corner points and non-fault caused disturbance can be eliminated according to the calculated distance between two neighbour corner points and the angle of the corner point. The proposed method is proved feasible and effective by digital simulated test.

Laboratory Test Results for the Travelling Wave Fault Location Scheme

Laboratory Test Results for the Travelling Wave Fault Location Scheme

Travelling Wave Fault Location for Distribute Cable Network Based on Distributed Measurement

This template carries out a three-terminal accurate fault location method for distribute cable network. It is improved from type D principle fault location method. Radial distribution network is decomposed into T-type networks. A set of formulas based on three-terminal data can calculate fault distance and find fault branch. Only first transient wave heads is needed. Shorter transmission distance makes it more accurate to extract first wave heads with wavelet. The distributed measurement offers redundant transient voltage data. These data is fully used to improve location success rate and accuracy. The simulation result in ATP-EMTP shows that the location accuracy isnt influenced by wave speed, catadioptric wave, grounding resistance and initial fault phase angle.

Application Research on Natural Frequency Method in Single Terminal Traveling Wave Fault Location

A method is provided to make natural frequency method be applied to single terminal traveling wave fault location in the paper. A group of fault distance suspected is calculated by single terminal method of traveling wave fault location method firstly, then deal with current travelling wave of fault by FFT to get the natural frequency reflecting fault location so that a fault distance can be calculated by it. Contrast the fault distance from natural frequency method and everyone of the group of fault distance suspected from single terminal method of traveling wave fault location method to determine the suspected fault distance closed to it is the calculation results we want. Numerical simulation shows the method can improve effectively the reliability of single terminal traveling wave fault location.

A Traveling-Wave Detection Method Based on Park's Transformation for Fault Locators

A novel algorithm for transient detection based on Park's transformation is proposed. It is very simple, self-adapts to electrical noise and phase imbalances, and is appropriate to be used in connection with traveling-wave fault location (TWFL) methods. The proposed technique is evaluated through Electromagnetic Transients Program simulations. A 230-kV transmission system case study is carried out, in which power system voltage and current waveforms are picked up one sample at a time. It is shown that the method is very reliable and suitable for multiterminal TWFL algorithms.

Modeling Technology in Traveling-Wave Fault Location

Theoretical research and equipment development of traveling-wave fault location seriously depend on digital simulation. Meanwhile, the fault-generated transient traveling wave must be transferred through transmission line, mutual inductor and secondary circuit before it is used. So this paper would maily analyze and summarize the modeling technology of transmission line and mutual inductor on the basis of the research achievement. Firstly several models of transmission line (multiple Π or T line model, Bergeron line model and frequency-dependent line model) are compared in this paper with analysis of wave-front characteristics and characteristic frequency of traveling wave. Then modeling methods of current transformer, potential transformer, capacitive voltage transformer, special traveling-wave sensor and secondary cable are given. Finally, based on the difficult and latest research achievements, the future trend of modeling technology in traveling-wave fault location is prospected. DOI: http://dx.doi.org/10.11591/telkomnika.v11i6.2691 Full Text: PDF

Wide-Area Traveling Wave Fault Location System Based on IEC61850

Existing traveling wave fault location systems employ the double-end method and do not make use of data from neighboring substations. If one of the data acquisition equipments at either end of a line fails to capture the fault transient, no fault location result can be obtained. A wide-area traveling wave fault location (WA-TWFL) system, which makes use of traveling wave data from various substations across the monitored network, is introduced. The WA-TWFL algorithm first identifies the area of the monitored network in which the source of the disturbance originated by analyzing the traveling wave propagation times using the extended double end method. Then, the faulty line, and the distance to fault, are determined using selected records from the identified area of the disturbance. This approach provides fault location reliability than the traditional TWFL algorithm. Traveling wave data models based on IEC61850, which supports open communication and interoperability between data acquisition equipment and the master station of the WA-TWFL, are also presented in this paper. The feasibility of the proposed algorithm is proved using traveling wave data from an actual fault on a power grid in China.

An Improved Wide Area Travelling Wave Fault Location Algorithm

In order to enhance the reliability of traveling wave fault location (TWFL) systems, an improved wide area traveling wave fault location (WA-TWFL) algorithms is presented in this paper. In the disturbance area that near to the fault position, we can first get the possible fault positions by using the outgoing path data from the substation that first records the initial traveling wave, then use the possible fault position to verify the reasonableness of data recorded. The fault position that has no counter-example in logical is the real fault position. EMTP simulation verifies the validity and applicability of this algorithm.

A fault location method based on genetic algorithm for high‐voltage direct current transmission line

SUMMARYA fault location method based on genetic algorithm for high‐voltage direct current (HVDC) transmission line is proposed in this article. This method adopts the Bergeron model of transmission line, in which the voltage at any point of the line can be calculated by the voltage and current data sampled at both terminals of the line, and the fault position can be identified using the distributed characteristics of voltage along the line. Unlike the traditional fault location methods based on the Bergeron model, which depend on accurate line parameters and highly synchronized samples at two terminals of the line, the proposed method takes line parameters and asynchronous time at two terminals of the line together with the unknown fault location as the variables in model building to obtain the fault location. As an optimization problem, the model is solved by genetic algorithm. The significant advantage of the method is that it can reduce the influence of line parameter deviation and asynchronous samples at two terminals to the fault location result. The purpose of proposing this method is to avoid the situation without location result for the traveling wave fault location method when a grounding fault occurred with high resistance and to improve the accuracy of fault location result under harsh environment condition. The simulation model of a typical 500 kV HVDC transmission line in the Chinese power system was built by PSCAD, and MATLAB was used to verify the algorithm. Actual fault recording data obtained from the south grid of China were used to test the effectiveness of this method. Simulation results show that the proposed method is valid and is capable of eliminating the influence of line parameters deviation and asynchronous data on the accuracy of fault location results for the HVDC transmission line. Copyright © 2012 John Wiley & Sons, Ltd.

Issues of One-Terminal Traveling Wave Fault Location Using Wavelet

One-terminal fault location provides many advantages including its simple principle, high relative reliability, low cost and high precision. But there still be some problems in practice, such as detection of wave front, calculation of wave velocity and identification of source of reflected wave. In order to settle the problems above, decoupling methods, acquisition of traveling wave signals, calculation of wave velocity, key factors influencing precision of fault location and so on are discussed. This paper will be of importance in the research of one-terminal fault location method and further improvement of reliability and precision.

Travelling wave time–frequency characteristic-based fault location method for transmission lines

Single-ended travelling wave fault location methods have the advantages of avoiding the complexities and costs of the remote-end synchronisation. However, the determination of the arrival time of the travelling wave and its corresponding propagation velocity is a difficult problem which is apt to limit the algorithms’ accuracy. A novel single-ended fault location method based on travelling wave time–frequency characteristics for transmission lines is proposed in this study. The time–frequency characteristics of the travelling wave signal are described by the Lipschitz exponent. The Lipschitz exponent of the second transient wave-front signal is estimated by using the wavelet transform and the least square method. Afterwards the frequency component of the travelling wave, which is best for fault location, and its corresponding arrival time and propagation velocity can be determined. Then the proposed method calculates the fault distance precisely based on the determined time and velocity. Extensive simulations have been carried out in PSCAD/EMTDC, and the results demonstrate that the accuracy of the proposed fault location method is significantly improved comparing with that of the traditional travelling wave fault location method. The proposed method is insensitive to different fault conditions, and it adapts to both transposed and untransposed lines well.

The Research of Traveling Wave Fault-Location Methods for the 10kv Distribution Networks

The 10kV distribution networks have complicated geographical environment and the lines with many branches, as well as high grounding resistance at fault point, thus result the difficult of locating fault. Traveling wave fault-location methods locate fault by the time of traveling wave from fault point to receiver or wave subtraction from fault point to two sides receivers, and the advantages of the methods are fast and have high precision. This paper introduced A, B, C, E four types traveling wave fault-location methods and their characteristics. Many simulations are taken for single-phase earth fault in a 10kV power distribution line with branches. By comparing the waves reflected from normal line and the fault one, the fault distance is determined by the first distortion point. As a result, the simulations indicate that the fault-location precision meet the actual requirement, Type C traveling wave fault-location method is feasible for the fault location in distribution networks.

Travelling Wave-Based Fault Location Scheme for Aged Underground Cable Combined with Overhead Line

This paper presents a novel wavelet-based travelling wave fault location algorithm for aged underground cables in transmission systems. Such transmission systems consist of overhead lines combined with underground power cables. Applying the singularity detection feature of wavelets as a powerful signal processing tool, the first and second initial arrival of the voltage travelling waves at the first end of the overhead as well as at the terminal end of the aged cable line can be identified reliably without the need for detection the sign of these waves. In this paper modal signals, rather than the phase signals, are the inputs to the relay.The proposed algorithm is capable of eliminating the effect of the change in the propagation velocity of the travelling waves over the age of the cable. It can be used on-line following the operation of digital relays or off-line using the data stored in the digital transient recording apparatus. Extensive simulation studies carried out using ATP/EMTP show that the proposed algorithm provides an accepted degree of accuracy in fault location under different fault conditions.

Improved GPS travelling wave fault locator for power cables by using wavelet analysis

Improved GPS travelling wave fault locator for power cables by using wavelet analysis

Improved GPS travelling wave fault locator for power cables by using wavelet analysis

The paper proposes an improved approach to cable-fault location, which is essentially based on synchronised sampling technique, wavelet analysis and travelling wave principle. After an outline of the new scheme and brief introduction to the three major techniques, wavelet analysis of faulty transient waveforms is conducted in details to determine the best wavelet levels for this particular application. Then a 400 kV underground cable system simulated by the Alternative Transient Program (ATP) under various system and fault conditions is used to fully evaluate the approach. Numerical results show that this scheme is reliable and accurate with errors of less than 2% of the length of the cable line.

GPS travelling wave fault locator systems: investigation into the anomalous measurements related to lightning strikes

A new fault location system based on the travelling wave principle and capable of locating faults on power lines to within /spl plusmn/one tower span (300 m) has been successfully developed and applied to BC Hydro's extensive 500 kV network. Unlike earlier schemes which are based on impedance measurements, its accuracy is not affected by load conditions, high grounding resistance and most notably series capacitor banks. This system measures the time of arrival of a fault-generated travelling wave at the line terminals using the precise timing signals from the Global Positioning System (GPS). Operating experience with the fault locator on lightning related faults indicated highly accurate results were obtained for the majority of the cases. In a few of the lightning-caused disturbances, the system gave anomalous measurements. This paper describes the operation of the system, summarizes the operating experience and explains the observed anomalous measurements.