Download or read book Sensitivity Analysis of Impedance based Fault Location Methods written by Neeraj Anil Karnik and published by . This book was released on 2011 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Impedance-based methods are used to locate faults on distribution systems because of their simplicity and ease of implementation. These methods require fault voltage and current data along with the positive- and zero-sequence line impedance values (in ohm per unit length) to estimate the reactance or distance to fault location. Inaccuracies in line impedance values, which arise from circuit model errors, have an adverse impact on fault location estimates of the impedance-based methods. Measurement errors in current and voltage transformers can also lead to inaccuracy in estimation. Further, all methods use simplistic models to represent the system load. The load in a practical distribution system does not conform to the oversimplified models leading to errors in estimation of fault location. This thesis presents sensitivity analysis of four impedance-based methods. It focuses on the Takagi, positive-sequence reactance, loop reactance and balanced-load methods. Amongst these four methods, the first three are commonly used for fault location. The fourth method was developed as a part of this work. The objective of sensitivity analysis is to study and quantify the effect of circuit model, measurement and load model errors, on the fault location estimates of the four methods. The results of this analysis are used to establish upper and lower bounds on the estimation errors for each method. The analysis begins with creation of a baseline case using a modified version of the IEEE 34 Node Test Feeder. All the methods estimate the reactance to fault location as a part of this analysis. The baseline case uses accurate line impedances and measurement values in the four methods. The fault location estimates for this case serve as a means of comparison for all subsequent analyzes. Secondly, various circuit model errors are introduced while computing the line impedance values. These errors include inaccurate modeling of four parameters viz. phase conductor distances, conductor sizes, phase to neutral conductor distances and earth resistivity. The erroneous line impedance values, which arise from these circuit model errors, are used in the four methods. The resultant location estimates are compared with those for the baseline case. It is observed that modeling errors in earth resistivity can cause estimation errors of 2% to 5% in the Takagi and positive-sequence reactance methods. These errors can be positive or negative depending upon whether the modeled earth resistivity value is more than or less than the accurate value. The effect of inaccurate modeling of the other three parameters is marginal. Additionally, the Takagi and positive-sequence reactance methods assume line impedances to be uniform while estimating fault location. Although this assumption is a type of circuit model error, it does not lead to significant errors in estimation. The loop reactance and balanced-load methods are insensitive to circuit model errors as they do not use line impedance values while estimating reactance to fault location. The next part is analysis of effect of measurement errors on fault location estimates. Ratio and phase angle errors are deliberately introduced in the current and voltage transformers and the erroneous measurements are used to conduct fault location. This causes 5% to 6% errors in estimation for the Takagi and positive-sequence reactance methods. These estimation errors can be positive or negative depending upon the magnitude of the CT and VT ratio errors and the sign of the phase angle errors. For the loop reactance method, erroneous measurements introduce 8% to 30% errors in fault location. This indicates that the loop reactance method is highly sensitive to measurement errors. The balanced-load method is moderately sensitive and experiences 6% to 7% errors in fault location estimates. Lastly, the effect of load current on fault location estimates is analyzed. When the Takagi and positive-sequence reactance methods are used on a heavily loaded system, they estimate fault location with an error of 5% to 8%. The loop reactance method is severely affected by the level of load current in the system. This method can estimate fault location with nearly 100% accuracy, on a lightly loaded system. However, the estimation errors for this method increase significantly and are in the range of 15% to 30%, as load current in the system increases. In case of the balanced-load method, unbalanced, heavy loads can cause estimation errors of 7% to 25%. The combined effect of all the error sources is taken into account by creating a confidence interval for each method. For the Takagi and positive-sequence reactance methods, the actual fault location can be expected to lie within ±10% of the estimated value. The fault location estimation error for the loop reactance and balanced-load methods is always positive. The actual reactance-to-fault is within -30% of the value estimated by these methods.

Download or read book Wide Area Power Systems Stability Protection and Security written by Hassan Haes Alhelou and published by Springer Nature. This book was released on 2020-09-21 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book proposes new control and protection schemes to improve the overall stability and security of future wide-area power systems. It focuses on the high penetration levels of renewable energy sources and distributed generation, particularly with the trend towards smart grids. The control methods discussed can improve the overall stability in normal and abnormal operation conditions, while the protection methods presented can be used to ensure the secure operation of systems under most severe contingencies. Presenting stability, security, and protection methods for power systems in one concise volume, this book takes the reader on a journey from concepts and fundamentals to the latest and future trends in each topic covered, making it an informative and intriguing read for researchers, graduate students, and practitioners alike.

Download or read book Fault Analysis and Model based Approach for Fault Location in Modern Grids written by Sundaravaradan Navalpakkam Ananthan and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Short-circuit faults are inevitable on transmission and distribution networks. Dispatching the maintenance crew directly to the location of the fault saves a significant amount of resources in the restoration process, which has motivated the development of several fault location approaches. Impedance-based fault location (IBFL) approaches are the most commonly used fault location methods in digital relays. However, each IBFL approach is designed specific to a line or network configuration and is not universal. Furthermore, they suffer from several sources of errors and do not fully utilize valuable information about the power system surrounding the faulted line that is available. This dissertation presents a novel fault location approach that utilizes a system model to overcome these limitations. The concept of the proposed model-based fault location (MBFL) approach is to estimate the fault location by identifying the closest match among various fault scenarios simulated using the system model and the actual fault scenario. A key benefit of the proposed approach is identifying the location of a fault on a neighboring line using limited measurements, as few as only the through fault current flowing in a neighboring line. Application methods for implementing MBFL efficiently and effectively have been developed, with each technique having its unique benefits. The advantages of the proposed MFBL approach and the practical applicability of each implementation technique have been demonstrated using simulations on complex network configurations as well as field data of fault events. This work also contributes towards tools to supplement fault analysis applications in ac and dc systems. An algorithm to select an appropriate time instant in a fault record to extract phasors for post-fault event report analysis applications was developed. In low-voltage dc distribution systems, fault signatures of series-arc faults were identified to aid arc detection. Overall, the research work presented in this dissertation makes substantive contributions to fault location and fault analysis in transmission and distribution systems

Download or read book Computational Methods for Fault Location on Electric Power Transmission Lines written by Staffan E. Westlin and published by . This book was released on 1976 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Online Location of Faults on AC Cables in Underground Transmission Systems written by Christian Flytkjær Jensen and published by Springer Science & Business Media. This book was released on 2014-03-19 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on various techniques for fault location on cross bonded cables, identifies the best method and describes the construction of a full fault locator system. The developed system is able of pinpointing the fault location on long cross-bonded cable systems and will be installed in Danish substations for monitoring the coming cable-based transmission grid. The work was conducted as part of a collaborative project between the department of energy technology at Aalborg University and the Danish transmission system operator for electricity and natural gas, Energinet.dk.

Download or read book Distribution Fault Location Using Short circuit Fault Current Profile Approach written by Swagata Das and published by . This book was released on 2011 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Popularly used impedance-based methods need voltage and current waveform as well as line impedance per unit length to estimate distance to fault location. For a non-homogenous system with different line configuration, these methods assume that the system is homogenous and use the line impedance of the most frequently occurring line configuration. Load present in the system before fault is an important parameter which affects fault location accuracy. Impedance-based methods like Takagi and positive-sequence method assume that the load is lumped beyond the fault point which may not be true for a typical distribution system. As a result, accuracy of the impedance-based methods in estimating distance to fault is affected. Another short-coming of impedance-based methods are that they are unable to identify the branch in which the fault may be located. To minimize these errors, this thesis proposes a short-circuit fault current profile approach to complement impedance-based algorithms. In the short-circuit fault current profile approach, circuit model of the distribution feeder is used to place faults at every bus and the corresponding short-circuit fault current is plotted against reactance or distance to fault. When a fault occurs in the distribution feeder, fault current recorded by relay is extrapolated on the current profile to get location estimates. Since the circuit model is directly used in building the current profile, this approach takes into account load and non-uniform line impedance. Using the estimates from short-circuit fault current profile approach and impedance-based methods, the path on which the fault is located is identified. Next to improve fault location estimates, a median value of the estimates is computed. The median is a more robust estimate since it is not affected by outliers. The strategy developed above is tested using modified IEEE 34 Node Test Feeder and validated against field data provided by utilities. For the IEEE 34 Node Test Feeder, it is observed that the median estimate computed from impedance-based methods and the short-circuit fault current profile approach is very close to the actual fault location. Error in estimation is within 0.58 miles. It was also observed that if a 0.6 mile radius is built around the median estimate, the fault will lie within that range. Now the IEEE 34 Node Test Feeder represents a typical distribution feeder and has also been modeled to represent the worst case scenario, i.e. load current is around 51% of the fault current for the farthest bus. Hence the 0.6 mile radius around the median estimate will hold true for most distribution feeders and will be used when computing the fault range for field case events. For the field events, it was seen that the actual faults indeed lie within the 0.6 mile radius built around the median estimate and the path of the fault location has also been accurately estimated. For certain events, voltage waveform was not useful for analysis. In such situations, short-circuit fault current profile alone could be used to estimate fault location. Error in estimation is within 0.1 miles, provided the circuit model closely represents the distribution feeder.

Download or read book Fault Location on Transmission and Distribution Lines written by Swagata Das and published by John Wiley & Sons. This book was released on 2021-11-22 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with up-to-date coverage of fault location algorithms in transmission and distribution networks. The algorithms will help readers track down the exact location of a fault in the shortest possible time. Furthermore, voltage and current waveforms recorded by digital relays, digital fault recorders, and other intelligent electronic devices contain a wealth of information. Knowledge gained from analysing the fault data can help system operators understand what happened, why it happened and how it can be prevented from happening again. The book will help readers convert such raw data into useful information and improve power system performance and reliability.

Download or read book Applications of Impedance based Fault Locating Methods in Power Systems written by Kyung Woo Min and published by . This book was released on 2014 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concentration of this work is in estimating fault locations in power systems. After describing the basic concepts of fault locating methods, this work describes improving the fault location estimates, applying the fault locating methods, and implementing the methods in a software. Every work described in the Chapter will be evaluated whether by actual field data or simulated data based on field parameters.

Download or read book Fault Location on Power Networks written by Murari Mohan Saha and published by Springer Science & Business Media. This book was released on 2009-11-25 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fault Location on Power Lines enables readers to pinpoint the location of a fault on power lines following a disturbance. The nine chapters are organised according to the design of different locators. The authors do not simply refer the reader to manufacturers’ documentation, but instead have compiled detailed information to allow for in-depth comparison. Fault Location on Power Lines describes basic algorithms used in fault locators, focusing on fault location on overhead transmission lines, but also covering fault location in distribution networks. An application of artificial intelligence in this field is also presented, to help the reader to understand all aspects of fault location on overhead lines, including both the design and application standpoints. Professional engineers, researchers, and postgraduate and undergraduate students will find Fault Location on Power Lines a valuable resource, which enables them to reproduce complete algorithms of digital fault locators in their basic forms.

Download or read book Proceedings of the 5th International Conference on Electrical Engineering and Automatic Control written by Bo Huang and published by Springer. This book was released on 2016-07-15 with total page 1217 pages. Available in PDF, EPUB and Kindle. Book excerpt: On the basis of instrument electrical and automatic control system, the 5th International Conference on Electrical Engineering and Automatic Control (CEEAC) was established at the crossroads of information technology and control technology, and seeks to effectively apply information technology to a sweeping trend that views control as the core of intelligent manufacturing and life. This book takes a look forward into advanced manufacturing development, an area shaped by intelligent manufacturing. It highlights the application and promotion of process control represented by traditional industries, such as the steel industry and petrochemical industry; the technical equipment and system cooperative control represented by robot technology and multi-axis CNC; and the control and support of emerging process technologies represented by laser melting and stacking, as well as the emerging industry represented by sustainable and intelligent life. The book places particular emphasis on the micro-segments field, such as intelligent micro-grids, new energy vehicles, and the Internet of Things.

Download or read book Improving Fault Location Through Interpole Analysis of Circuit Breaker and Automatic Reclose Scheme Operation written by Liang Ji and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research concentrates on the development and evaluation of novel single ended impedance based fault location methods, which are easy and economical to implement in practice. The conventional single ended impedance based fault location methods normally suffer from negative effects associated with variability and inaccuracies in fault resistance, distance to fault and from the impact of variable remote end short circuit level. A novel concept of a single ended impedance based fault location method using analysis of 'interpole' states, which arise during the operation of the circuit breaker as the individual poles open sequentially, has been developed. The proposed fault location technique has been shown to have a very high theoretical accuracy by eliminating the aforementioned negative effects associated with conventional single ended impedance based methods. The thesis describes how the developed technique operates through comparing simulated voltage and currents during the interpole states with the actual measured voltage and currents, and searches for a match that may be indicative of fault location. When a match is found within a pre-specified tolerance error from analysis of the initial "during fault" state, the ranges of corresponding possible fault locations, fault resistances and remote end short circuit levels used in the simulation are noted. The ranges of all possible values are subsequently reduced through analysis of the consecutive interpole stages as each pole of the circuit breaker opens sequentially to finally interrupt the flow of current in all three phases. The final, most accurate, fault location is obtained following on from analysis of the final state. Another single ended impedance based fault location method has been developed that extends the analysis to the operation of single/three phase auto-reclose schemes. Similarly with previous method, the second method also uses the analysis of different system states, which are arisen during the auto-reclose operation, and improves on the accuracy of the method that only analyses the single operation of the circuit breaker. The methods are demonstrated using EMTP/ATP simulation models for a variety of different cases and it is shown how high accuracy has been achieved, with improved performance when compared with conventional single ended impedance based method (Takagi method and network impedance method). Additionally, it is a potentially economic solution, as only local end data is required. The thesis concludes with an overview of ongoing and future work that has the intention of moving the work forward towards implementation within commercially available relay hardware.

Download or read book Fault Location and Analysis in Transmission and Distribution Networks written by Swagata Das and published by . This book was released on 2015 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: Short-circuit faults are inevitable on transmission and distribution networks. In an effort to provide system operators with an accurate location estimate and reduce service restoration times, several impedance-based fault location algorithms have been developed for transmission and distribution networks. Each algorithm has specific input data requirements and make certain assumptions that may or may not hold true in a particular scenario. Identifying the best fault location approach, therefore, requires a thorough understanding of the working principle behind each algorithm. Moreover, impedance-based fault location algorithms require voltage and current phasors, captured by intelligent electronic devices (IEDs), to estimate the fault location. Unfortunately, voltage phasors are not always available due to operational constraints or equipment failure. Furthermore, impedance-based fault location algorithms assume a radial distribution feeder. With increased interconnection of distributed generators (DGs) to the feeder, this assumption is violated. DGs also contribute to the fault and severely compromise the accuracy of location estimates. In addition, the variability of certain DGs such as the fixed-speed wind turbine can alter fault current levels and result in relay misoperations. Finally, data recorded by IEDs during a fault contain a wealth of information and are prime for use in other applications that improve power system reliability. Based on the above background, the first objective of this dissertation is to present a comprehensive theory of impedance-based fault location algorithms. The contributions lie in clearly specifying the input data requirement of each algorithm and identifying their strengths and weaknesses. The following criteria are recommended for selecting the most suitable fault location algorithm: (a) data availability and (b) application scenario. The second objective is to develop fault location algorithms that use only the current to estimate the fault location. The simple but powerful algorithms allow system operators to locate faults even in the absence of voltage data. The third objective is to investigate the shortcomings of existing fault location algorithms when DGs are interconnected to the distribution feeder and develop an improved solution. A novel algorithm is proposed that require only the voltage and current phasors at the substation, is straightforward to implement, and is capable of locating all fault types. The fourth objective is to examine the effects of wind speed variation on the maximum and minimum fault current levels of a wind turbine and investigate the impact on relay settings. Contributions include developing an accurate time-domain model of a fixed-speed wind turbine with tower shadow and wind shear and verifying that the variation in wind speed does not violate relay settings calculated using the IEC 60909-0 Standard. The final objective is to exploit intelligent electronic device data for improving power system reliability. Contributions include validating the zero-sequence impedance of multi-terminal transmission lines with unsynchronized measurements, reconstructing the sequence of events, assessing relay performance, estimating the fault resistance, and verifying the accuracy of the system model. Overall, the research presented in this dissertation aims to describe the theory of impedance-based fault location, identify the sources of fault location error, propose solutions to overcome those error sources, and share lessons learned from analyzing intelligent electronic device data. The research is expected to reduce service downtime, prevent protection system misoperations, and improve power quality.

Download or read book Line Current Differential Protection written by Hector J. Altuve and published by . This book was released on 2014-06-15 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Global Sensitivity Analysis of Fault Location Algorithms written by Hoong Boon Ooi and published by . This book was released on 2008 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Big Data Application in Power Systems written by Reza Arghandeh and published by Elsevier. This book was released on 2024-07-01 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Big Data Application in Power Systems, Second Edition presents a thorough update of the previous volume, providing readers with step-by-step guidance in big data analytics utilization for power system diagnostics, operation, and control. Bringing back a team of global experts and drawing on fresh, emerging perspectives, this book provides cutting-edge advice for meeting today's challenges in this rapidly accelerating area of power engineering. Divided into three parts, this book begins by breaking down the big picture for electric utilities, before zooming in to examine theoretical problems and solutions in detail. Finally, the third section provides case studies and applications, demonstrating solution troubleshooting and design from a variety of perspectives and for a range of technologies. Readers will develop new strategies and techniques for leveraging data towards real-world outcomes. Including five brand new chapters on emerging technological solutions, Big Data Application in Power Systems, Second Edition remains an essential resource for the reader aiming to utilize the potential of big data in the power systems of the future. - Provides a total refresh to include the most up-to-date research, developments, and challenges - Focuses on practical techniques, including rapidly modernizing monitoring systems, measurement data availability, big data handling and machine learning approaches for processing high dimensional, heterogeneous, and spatiotemporal data - Engages with cross-disciplinary lessons, drawing on the impact of intersectional technology including statistics, computer science, and bioinformatics - Includes five brand new chapters on hot topics, ranging from uncertainty decision-making to features, selection methods, and the opportunities provided by social network data

Download or read book Investigation of Fault Location Performance Utilizing Synchronized Phasor Measurements with a Two ended Fault Location Impedance Method written by Enrique Quintero and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transmission lines are an essential part of the electrical grids. Thus, utilities cannot afford to have any transmission line out service because it can result in power outages and causes overloading other lines in the same grid. However, transmission lines are exposed to faults caused by short circuits, birds, adverse weather conditions, and human made accidents. Transmission line faults can be temporary or permanent. Temporary faults are mostly self-cleared. But, permanent faults do not self-cleared and cause damage to transmission line infrastructure. Most of these faults result in mechanical damage to power lines, poles, or insulators which need to be repaired before returning the line to service. For this reason, transmission line faults must be located accurately to allow field crews arrive at the scene and repair the faulted equipment as soon as possible. The most obvious method to locate the faulted equipment is just to patrol the whole line, but one of the main obstacles following that method are the geographical layout in some sections of the line making difficult for the field crews accessing to the scene, the long time it takes to patrol the line and the associated high cost which makes it uneconomical. Meanwhile, if the utility has a software tool to calculate fast and accurate fault location under any power system conditions, the utility will enhance the restoration time of the line with less cost and consequently it will short customer outage time by pointing field crews to narrow range to check. Fault location algorithms are one method for utilities use to detect fast and accurate fault location. However these fault location algorithms are typically embedded in fault locator devices or protective relays. This is an obstacle because in order to get the fault location out those devices, they need to be interrogated and normally these devices are located in remote areas. Now with the advances in synchrophasor technology, it is possible to collect synchronized phasor measurements in a convenient central location such as operating center or dispatch center and perform fast and accurate fault location based on synchronized phasor measurements. For this thesis, an impedance based fault location technique will be used because it is the most simple and practical method for implementation. However, this fault location technique in conjunction with relay data is known for being susceptible to a number of sources of errors. So by utilizing real-time and very accurate synchronized phasor measurement data, this thesis will investigate how accurate the impedance based fault location technique result.

Download or read book Modeling Enhancement and Intelligent Inference of Impedance based Structural Health Monitoring written by Qi Shuai and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: