Traveling Wave Based Fault Location Research Articles

Improving Traveling Wave-Based Transmission Line Fault Location by Leveraging Classical Functions Available in Off-the-Shelf Devices

This letter presents a practical methodology to improve traveling wave (TW)-based fault location (TWFL) on transmission lines by leveraging classical single- and double-ended TWFL functions available in off-the-shelf relays and digital fault recorders. It eliminates negative effects of uncertainties in line propagation velocity and travel time, being free of time-consuming or complicated procedures. Real TW records are studied to demonstrate that the proposed solution can improve the accuracy and reliability of TWFL estimations when uncertainties about line propagation velocity or travel time exist.

A single-ended traveling wave based fault location method using DWT in hybrid parallel HVAC/HVDC overhead transmission lines on the same tower

A single-ended traveling wave based fault location method using DWT in hybrid parallel HVAC/HVDC overhead transmission lines on the same tower

How much “villain” is the anti-aliasing filter for traveling wave-based fault location methods?

This paper analyzes the influence of anti-aliasing filters (AAFs) on traveling wave (TW)-based fault location (TWFL) methods. To do so, the Alternative Transients Program (ATP) is used to simulate several fault scenarios on a 230 kV/60 Hz test power system, allowing the assessment of AAFs influence when different TW filters and TWFL algorithms are used. The main goal is to clarify how much “villain” are the AAFs for TWFL methods if their cutoff frequencies are varied in noisy environments. By doing so, the most relevant spectrum band for TWFL solutions is investigated, addressing whether the application of AAFs with reduced cutoff frequencies would be critical or not. Although most people may think that the answer to this question is obvious, the obtained results show evidences that some solutions monitor transients within spectrum ranges wider than those they indeed require. Moreover, although AAFs can relevantly influence the performance of TWFL methods, it is proven that the application of AAFs with reduced cutoff frequencies is not necessarily critical, but rather, it depends on the used TW filters and TWFL methods, such that it can be beneficial when electrical noise is present in monitored signals.

Impact of transmission line modeling aspects on TW-Based fault location studies

This paper analyzes the impacts of different transmission line (TL) modeling approaches in Electromagnetic Transients Programs (EMTP) during the evaluation of traveling wave (TW)-based fault location (TWFL) functions. Massive EMTP fault simulations are carried out to compare the performance of TWFL solutions when the system model considers Bergeron or JMarti models, accounting for homogeneous or heterogeneous soil characteristics, as well as ideal or real transposition schemes. Firstly, TWFL errors are presented in the form of scatter plots to compare the relative performance between four fault location solutions when different modeling approaches are taken into account. Then, the fault location absolute errors are presented as boxplots individually for each analyzed TWFL method and modeling approach, allowing to perform quantitative analysis of the obtained errors. From these results, the impacts of the evaluated modeling strategies on the assessed TWFL methods are addressed, highlighting the model features that can yield more challenging scenarios during the evaluation of TWFL solutions.

Travelling Wave Fault Location of HVAC Transmission Line Based on Frequency-Dependent Characteristic

Travelling wave (TW) fault location has been widely utilized for high-voltage alternating current (HVAC) transmission lines, which is proven to have a higher accuracy than conventionalpower frequency data based fault location. However, as known, the performance of travelling wave-based fault location (TWFL) principles is often challenged by several factors including fault location, fault initial angle, fault resistance as well as frequency dependency of HVAC transmission lines. In this context, this paper proposes a novel off-line TW fault location principle for transposed HVAC transmission lines to address the robustness against those uncertain factors. Firstly, the frequency-dependent characteristic of HVAC transmission lines is analyzed. Then upon that, a novel TW fault location principle is proposed, which consists of two important components: i) arrival time detection of TW and ii) accurate frequency calculation of TW. Eventually, simulations are carried out on a 500 kV AC transmission system using PSCAD/EMTDC to validate the effectiveness of the proposed method and itsrobustness against different fault types, resistances, locations, initial angles and noises.

Evaluation of travelling wave-based fault location methods applied to HVDC systems

This paper presents a thorough evaluation of travelling wave (TW)-based fault location (TWFL) methods when applied to High Voltage Direct Current (HVDC) systems. All tests are carried out using a Cigre benchmark model which represents a Brazilian HVDC system. Simulations are carried out by means of the Alternative Transients Program (ATP), through which different pole-to-ground and pole-to-pole fault scenarios are analyzed. Four TWFL approaches are implemented and evaluated, and frequency independent and dependent line models are taken into account to investigate the impacts of line parameter uncertainties and transient attenuation on the analyzed techniques. From the obtained results, the accuracy and main sources of errors of each TWFL approach are discussed, pointing out practical application aspects important to the industry.

A Traveling Wave-Based Fault Location Method Employing VMD-TEO for Distribution Network

In this paper, a traveling wave based fault location method is proposed for distribution networks. Before fault occurs, an intrinsic distance difference matrix (IDDM) is established based on the characteristics of traveling wave propagation and the topology of distribution network. After the fault, the initial fault traveling wave signals are decomposed into several intrinsic mode function (IMF) signals by variational mode decomposition (VMD), and the first IMF signal is analyzed by teager energy operator (TEO) to determine the arriving time of initial fault traveling waves. According to the double-ended traveling wave method and the arrival time of traveling wave at all recorders, a fault distance difference matrix (FDDM) is built. By comparing the difference between IDDM and FDDM, a fault branch determination matrix (FBDM) and the lateral index Q are used to locate the fault. The effectiveness of the proposed method is verified via EMTP/ATP simulations. Results show that the proposed method has a high fault location accuracy, and does not need that all terminals of lines are installed traveling wave recorders.

Analysis of traveling wave based fault location method for distribution network with image processing

Laws of traveling wave data related to fault location for medium voltage distribution network are discussed and summarized. Given the tree structure of a distribution network, an image of nodes voltage is created combining the use of real-time traveling wave meters at all nodes of the tree. The novelty of this paper is that travelling wavefront are analyzed based on the dynamic changes of these images. Based on principle of the traditional fault location with traveling wave-based method for transmission networks, traveling wave data of fault location for medium voltage distribution networks are plotted in order to estimate propagation velocity and distance between the fault position and the reference node. The results indicate that taking advantage of the laws of data related to first wave front can improve the reliability of the fault location for medium voltage networks.

Modeling and simulation of intermittent arc effects on traveling wave based fault location techniques for distribution network

With rapidly developing of the distribution networks the rate of the earth fault increases sharply. Aiming to fault location for distribution networks, many techniques are proposed and applied in distribution networks throughout the world. However, until now the technology for precise fault point location has not been successfully implemented in engineering practice. Traveling wave based methods as common techniques are widely applied in transmission line protection for locating fault point. However, these methods face severe challenge in fault location for distribution networks. The main reason is that the intermittent arc fault easily results in failure of detecting inceptive travelling wave and this intermittent arc is a common earth fault in distribution networks compared with transmission networks. In this paper, a simplified distribution line is built by making reference to the two parallel lossless transmission lines system. Then, the intermittent arc effects on traveling wave based method are modeled and discussed. Finally, the reason why these travelling wave based methods are hard to locate fault point precisely is illustrated.

Traveling wave based fault location for power transmission lines using morphological filters and clarke modal components

This article presents a fast and accurate fault location approach for power transmission lines based on the theory of traveling waves. In fact, when faults occur, they give rise to transient voltages and currents that propagate at a speed close to that of light along the transmission line as traveling waves. Moreover, according to the superposition theorem, each of these transients is a combination of a steady-state quantity and an incremental quantity. These transient signals measured at both ends of the line are first transformed to the Clarke (0-α-β components) components in order to categorize the type of faults, and then multi-scale morphological gradient filters are used to extract equivalent quantities to the incremental quantities to form what are called characteristic signals. These latter will be used to identify the fault location according to the proposed algorithm.

Model Free Traveling Wave Based Fault Location Method for Series Compensated Transmission Line

Locating fault position in a series compensated transmission line is a difficult task due to the non-linear characteristics of the metal-oxide varistor which is present in the protection system of the compensator. In this paper, a model-free two-terminal traveling wave-based fault location method for a series compensated line is proposed. The technique makes use of two subroutines which calculate the fault locations assuming that the fault position to be on the left and right side of the series compensator respectively. The method then selects the correct fault location of the two by a special logic based on faulted half-section identification. The first two traveling wave arrival times recorded at both the terminals of the line are used in the method. The proposed technique does not require model information of the series capacitor and transmission line. It has been verified using the PSCAD/EMTDC model of a 400-kV, 300 km transmission line which is compensated by a fixed series capacitor in the middle and line ends. The performance of the proposed method is compared with a commercially available classical two-ended techniques and setting-free method.

Dynamic protection of power systems with high penetration of renewables: A review of the traveling wave based fault location techniques

Governments set more ambitious goals about CO2 emission reductions and increasing the share of clean energy in the overall generation portfolio. A natural outcome of this trend is more deployment of renewables both at transmission and distribution networks. In addition to well-known environmental benefits, introduction of these non-conventional technologies changes the operation of power systems: e.g. reduced inertia, less stability and more unpredictability. Since most of these novel generation technologies are inverter-interfaced, their behavior under fault conditions are much different than conventional rotating machines. This creates novel challenges in power system protection. Accurate determination of location and type of a fault provides faster system restoration, increased reliability and cost benefits. There are various methods utilized for power system protection. Travelling wave-based fault location methods are preferred due to high accuracy and ultrafast detection capability. This paper reviews the latest developments in traveling wave-based fault location techniques. Signal processing methods hold a key role in information extraction since traveling wave transients have high frequency. A critical review of these methods reported in literature is presented. Application of travelling wave-based protection techniques is examined and special focus is given to distribution systems with high penetration of renewable energy-based generators. Traveling wave-based protection techniques have tremendous potential for future protection applications in smart grid scenarios viz. microgrids and active distribution systems. Being able to detect a fault under different current and voltage conditions make them a very strong candidate for achieving adaptive protection in power systems with high penetration of renewables. Finally, implementation of travelling wave-based fault location system based on IEC 61850 standard is also investigated. Having a standardized implementation is a solid step towards achieving plug-and-play (PnP) in dynamic power networks.

Adaptive single-phase/three-phase reclosing scheme for transmission lines in passive network supplied by MMC-HVDC

Modular multilevel converter (MMC) shows prominent advantages on supplying passive networks, which are usually classified by power supply shortage and relatively weak structure. In order to reduce the unnecessary outage time and improve the system stability, an adaptive ac auto-reclosing scheme for passive networks is proposed based on characteristic signal injection. Additional MMC controller is designed to inject the characteristic signals into the healthy line, which in turn induces corresponding signals to the faulty line. Then fault properties are assessed by the travelling wave based fault location method. Finally, an adaptive auto-reclosing scheme is proposed to shorten the reclosing time and avoid the second fault shock to a large extent. The proposed scheme could be applied for both single-circuit and multi-circuit transmission lines. The simulation results obtained from PSCAD/EMTDC verify the effectiveness of the proposed method.

Performance Evaluation of Traveling Wave Fault Locator for a 220kV Hoa Khanh-Thanh My Transmission Line

This paper presents the traveling wave based fault location methods of SEL-400L, and SFL-2000 available on the market for a 66.9km, 220kV Hoa Khanh-Thanh My transmission line in Central Viet Nam, such as single-ended, and double-ended, all of which rely on measurements from inductive CTs and capacitive VTs. Focus was given on the building process of a Matlab Simulink model to evaluate these methods. Current and voltage signals were sent to an analog Chebyshev type II filter which passes higher frequency signals at 3kHz and rejects low frequencies signal at 50Hz. After that, these output signals are used in Clarke's transformation for getting 0 and α components. The detail coefficient of the selected components after DWT using Db4 wavelet at decomposition level 1 can be used to determine the fault types, the direction of fault and propose a crest-wave comparison solution to identify exactly the adjacent bus' reflected wave from the fault point's reflected wave for the fault location. Finally, the accuracy of fault location on the transmission line is reviewed by varying various parameters like fault type, fault location and fault resistance on a given power system model.

A Study of Travelling Wave Fault Location

In the present modern era with the development of power systems, fast and accurate faults locations becoming more and more important. Power grids produce transient travelling wave signals, which transmit along the transmission line to each substation with the speed approaching the velocity of light. Using the exact arrival time of the fault traveling wave and the waveform characteristics recorded at each substation, the traveling wave based fault location and protection can be realized. The fault location has high precision, and the protection has fast action speed. So, current transformer saturation low frequency oscillation and fault resistance cannot influence it. Fault location device (FLD) is installed at each substation in power grid, and travelling wave host computer is installed in control center. When a fault occurs, FLD records the switch operation information and the arrival time of the travelling wave, the information is then transmitted to the host computer. Lightning strike fault location method can only locate the fault caused by lightning, and it hardly satisfies the operation requirements in power system. Travelling wave fault location method with GPS is simple and with high precision, it has been applied in extra-high-voltage.

Automated double-ended traveling wave record correlation for transmission line disturbance analysis

Automating analysis and correlation of traveling wave data of the same fault event from two terminals of a transmission line is essential for automated double-ended traveling wave based fault location and disturbance analysis. This paper presents a traveling wave data detection and correlation matching method. This method is capable of detecting disturbance events on transmission lines obtained at different terminals based on synchronized data. The traveling waves caused by the same disturbance tend to be captured by multiple recording devices at different observation points, resulting in a significant change in only a few channels for each captured record. The waveform pixel ratio and the featured line of waveforms are extracted based on the possible disturbances that can be identified and recorded at a local database. The correlated searching and feature matching is executed for the remote record database. The correlated traveling wave data for disturbance events can be acquired and then used for locating the event and further analysis. The proposed method is able to extract the effective traveling wave segment corresponding to the same disturbance event from the database at different observation points. This facilitates the automated double-end location. Test results based on field data have demonstrated the effectiveness of the proposed method.

Review of Performance of Impedance Based and Travelling Wave Based Fault Location Algorithms in Double Circuit Transmission Lines

Parallel transmission lines or Double circuit transmission lines have been extensively utilized in modern power systems to enhance the reliability and security for transmission of electrical energy. This paper presents two fundamental algorithms: Impedance based, Travelling wave (TW) based algorithms for 100km, 400KV Double circuit transmission lines. MATLAB/ Simulink software was used to implement these algorithms. The accuracy of fault location on power transmission line are reviewed for these two methods by varying various parameters like fault type, fault location on a given power system model.

Travelling Wave Based Fault Location Analysis for Transmission Lines

This paper presents a review of the state of the art for fault location methods in transmission lines based on travelling waves. The motivations that led to these methods are explained historically. Also, a critical analysis, showing the advantages and disadvantages of each of them and their most common applications, is performed. Finally, a comparative analysis between two of the most widely used methods is carried out using real faults, in order to show the results’ sensitivity to changes in the line parameters.

A combined impedance and traveling wave based fault location method for multi-terminal transmission lines

A new fault location method suitable for multi-terminal transmission lines that combines the advantages of both impedance and traveling wave based methods has been developed and presented in this paper. The proposed method first determines whether the fault is grounded or ungrounded by comparing the magnitude of the ground mode wavelet coefficients at the measurement end. Next, the impedance based method is used to identify the faulted half of the line in the case of two-terminal line and the faulted line section as well as the faulted half of the line section in the case of multi-terminal lines. Finally the fault location is determined by taking the time difference between the first two consecutive aerial modes of the current traveling waves observed at one end of the multi-terminal line. The proposed method has been tested on four- and five-terminal transmission lines with different types of faults, fault resistances and fault inception angles using ATP simulation.

Modern travelling wave based fault location techniques for HVDC transmission lines

The modern travelling wave based fault location principles for transmission lines are analyzed. In order to apply the travelling wave principles to HVDC transmission lines, the special technical problems are studied. Based on this, a fault locating system for HVDC transmission lines is developed. The system can support modern double ended and single ended travelling wave principles simultaneously, and it is composed of three different parts: travelling wave data acquisition and processing system, communication network and PC based master station. In the system, the fault generated transients are induced from the ground leads of the over-voltage suppression capacitors of an HVDC line through specially developed travelling wave couplers. The system was applied to 500 kV Gezhouba-Nanqiao (Shanghai) HVDC transmission line in China. Some field operation experiences are summarized, showing that the system has very high reliability and accuracy, and the maximum location error is about 3 km (not more than 0.3% of the total line length). Obviously, the application of the system is successful, and the fault location problem has finally been solved completely since the line operation.