Download or read book Partial Discharge Classification Using Acoustic Signals and Artificial Neural Networks and Its Application in Detection of Defects in Ceramic Insulators written by Satish Kumar Polisetty and published by . This book was released on 2019 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Online condition monitoring of critical assets constitutes one method whereby the electrical insulation industry can help safeguard grids through the avoidance of system outages due to insulation failure. This thesis introduces a novel approach for monitoring the condition of outdoor ceramic insulators based on partial discharge (PD) measurements. The presence of physical defects such as punctures, broken porcelain, and cracks will ultimately lead to the initiation of PD activity in outdoor ceramic insulators. In addition to defects, surface discharges such as that caused by corona and dry band arcing are also very common, particularly in wet and polluted outdoor insulators. Such a discharge activity that originates in these kinds of conditions can cause flashover or insulator failure, resulting in power outages. Measuring early-stage discharge activity is thus very important as a means of avoiding catastrophic situations in power networks. The work presented in this thesis involved initial tests conducted to distinguish between different types of controlled discharges generated in the laboratory. The next step was the implementation of an artificial neural network (ANN) for classifying the type of discharge based on selected features extracted from the measured acoustic signals. First, relatively high-frequency acoustic signals are transformed into low-frequency signals using an envelope detection algorithm imbedded in the commercial acoustic sensor. A fast Fourier transform (FFT) is then applied to each low-frequency signal, and finally, 60 Hz, 120 Hz, and 180 Hz are used as input feature vectors for the developed ANN. This initial research was then extended to include testing of the proposed diagnostic tool on a practical insulation system, and outdoor ceramic insulators were selected for this purpose. Three types of defects were tested under laboratory conditions: a cracked ceramic insulator, a healthy insulator contaminated by wetting with salt water, and a corona generated from a thin wire wound to the ceramic insulator. Both a single disc, and three discs connected in an insulator string were tested with respect to these defects. For both controlled samples and full insulators, a recognition rate of more than 85 % was achieved.

Download or read book A Study of the Detection of Defects in Ceramic Insulators Based on Radio Frequency Signatures written by Shaharyar Anjum and published by . This book was released on 2014 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: The presence of defects in outdoor insulators ultimately results in the initiation of partial discharge (PD) activity. Because insulation failure and the consequent breakdown of power equipment can occur due to the cumulative adverse effects of partial discharges, it is important to detect PD activity in its early stages. Current techniques used in PD off-line analyses are not suitable for detecting defective insulators in the field. The work presented in this thesis involved the investigation of a number of cases of insulator defects, with the goal of developing an online RF-based PD technique for monitoring ceramic disc insulators that exhibit a variety of defects. The first three classes examined were an intentionally cracked ceramic insulator disc; a disc with a hole through the cap, which creates internal discharges; and a completely broken insulator disc. The fourth class involved an external corona noise using a point-to-plane setup. The defective discs were considered individually and were also incorporated into strings of 2, 3, and 4 insulators as a means of capturing the radiated RF signatures under external high voltage AC power. The captured RF pulses were processed in order to extract statistical, spectral, and wavelet packet based features. Feature reduction and selection is carried out and classification results pertaining to each feature-set type were obtained. To classify the discharges arising from different types of defects, an artificial neural network (ANN) algorithm was applied to the extracted features, and recognition rates of more than 90% were reported for each class. In addition, the position of the defective insulator within the string was varied and high defect classification results exceeding 90% were reported regardless of the position.

Download or read book Acoustic Detection of Partial Discharge Using Signal Processing and Pattern Recognition Techniques written by Anas Swedan and published by . This book was released on 2010 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In this thesis, artificial neural networks are utilized to enhance the acoustic PD detection under different insulation conditions. Experiemental results have shown that high detection rates of PD can be obtained under different conditions."--Abstract.

Download or read book Online Monitoring of Outdoor Non ceramic Insulators written by Ibrahim Yehia Shurrab and published by . This book was released on 2011 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The purpose of this study is not only detecting partial discharges in outdoor insulators, but also to identify sources of partial discharge using artificial intelligence. In outdoor insulators, partial discharges have four main sources: surface discharge, corona discharge from energized end, corona discharge from dead end and combination of both corona and surface discharge happening at the same time. Using feed forward back propagation neural network, a clear distinction between the four classes of partial discharges is achieved with 96.3% recognition rate."--Abstract, p. iii.

Download or read book Science Abstracts written by and published by . This book was released on 1993 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Condition Monitoring of Composite Insulator Using PD Analysis written by Ida Ayu Dwi Giriantari and published by LAP Lambert Academic Publishing. This book was released on 2009-09 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is written based on study that has been performed with the aim of investigating the use of the partial discharge (PD)measurement technique for use as an assessment tool of the composite insulator condition. A computer-based discharge analyser was utilised to study the phase-resolved PD patterns and their statistical distributions, and also PD scatter plots. The full PD impulse waveforms with their frequency spectra were also studied by using a high frequency current transformer (HF-CT) to be able to study a wide range of frequency components of the PD signals and to study the possibility of doing on-line PD measurement in service using such a method. The results of the computer discharge analyser have shown a quite good correlation to change of the insulator surface condition. It was also found when high frequency components appeared, surface deterioration could be expected to have occurred. The use of PD measurements in identifying artificial defects on composite insulators found that PD detection of such defects also gave an indication of location of hole type defects on the insulator.

Download or read book Remote Assessment of High Voltage Porcelain Insulators Using Radiated Electromagnetic Field Signature written by Ehsan Azordegan and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Automated Ultrasonic Signal Classification of Carbon Fiber Reinforced Plastic Laminates written by Sameeuddin Sameeuddin (‡e author) and published by . This book was released on 2014 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon composites, particularly carbon fiber reinforced plastics (CFRPs) are increasingly being used in many commercial applications such as automobile, aerospace, and civil infrastructures. This increase in the demand of CFRPs has led the manufacturers to research for ways of early detection and classification of defects in CFRP. This thesis work discusses the implementation of a Hopfield neural network (HNN) to automatically detect and classify defects in CFRP by ultrasonic testing (UT). Three of the most common and critical defects found in CFRP, i.e. foreign object (FO) inclusion, impact damage (ID), and porosity, were the main focus of this research. These defects were engineered into three different CFRP panels during manufacturing and were provided by an outside supplier. These panels were inspected on a standard immersion ultrasonic testing system in pulse-echo mode. One hundred time-amplitude based ultrasonic A-scan signals were recorded from the defected areas of each of the panels. Additionally, a hundred ultrasonic A-scan signals were recorded for the defect-free region of the CFRP. Signal preprocessing in terms of signal alignment is a vital process in any classification procedure as unaligned signals are prone to bad classification accuracies. Therefore, the raw A-scan signals were start-point aligned prior to any classification using cross-correlation technique. This research also focused on developing a feature extraction technique that could be used in conjunction with the HNN to classify the UT signals with high classification accuracy. A feature extraction technique based on gating technique was developed which consisted of five features, namely mean value of the signal, standard deviation of the signal, peak-to-peak amplitude value of the front wall echo (FEW), peak-to-peak amplitude value of the back wall echo (BWE), and time of flight (TOF) between FWE and BWE of each signal. Four other feature extraction techniques based on mean value of the signal, standard deviation value of the signal, fast Fourier transform (FFT), and discrete wavelet transform (DWT) were also used for the comparison and validation of results obtained by the developed feature extraction technique. The 100 signals for each category were randomly partitioned into equal-sized training and testing data sets. The partitioning was repeated for 1000 iterations, to average the results and obtain a robust estimate of the classification performance. The classification of the signals was carried out by implementing two approaches. The first approach utilized a dichotomous classification between each defect type and the non-defected region. And the second approach utilized a 4-class classification in which the defect types and the non-defected signals were classified at the same time. The results of this research showed that the classification accuracies for the 2-class problem obtained through the developed feature extraction technique exceeded 99%, which were in agreement with the results of classification obtained through the four conventional feature extraction techniques. The results of the 4-class problem obtained through the developed feature extraction technique exceeded 96% classification accuracy. For direct comparison, the results obtained from the four conventional feature extraction techniques exceeded 99% classification accuracies. Based on the results obtained, it can be concluded that the developed feature extraction technique can be used in conjunction with HNN to successfully classify defects in CFRP. With few modifications, the developed technique can be implemented to classify other types of defects in CFRP and can be implemented in different applications.

Download or read book Classifying Simulated Acoustic Sources Using a Backpropagation Neural Network written by and published by . This book was released on 1994 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes tools for simulating complex non-speech time series data of the type received by a hydrophone and a backpropagation artificial neural network for classifying the data. These tools can be used to investigate the utility of applying neural networks to the classification of passive sonar data. The tools use the Cmusic sound synthesis program for simulating the sounds received by a hydrophone. The neural network has three user interfaces, one graphical and two in the TTY mode for running experiments and on multiple platforms. The report includes a review of the artificial neural network approach, description of the neural network methods and tools, and an outline of the simulation of passive sonar signals.

Download or read book Generator Insulation Diagnostics Using Acoustic and Partial Discharge Characteristics written by Saber Azizi-Ghannad and published by . This book was released on 2000 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Voltage Engineering and Applications written by Ayman El-Hag and published by MDPI. This book was released on 2020-04-09 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of recent publications from researchers all over the globe in the broad area of high-voltage engineering. The presented research papers cover both experimental and simulation studies, with a focus on topics related to insulation monitoring using state-of-the-art sensors and advanced machine learning algorithms. Special attention was given in the Special Issue to partial discharge monitoring as one of the most important techniques in insulation condition assessment. Moreover, this Special Issue contains several articles which focus on different modeling techniques that help researchers to better evaluate the condition of insulation systems. Different power system assets are addressed in this book, including transformers, outdoor insulators, underground cables, and gas-insulated substations.

Download or read book Applications of Networks Sensors and Autonomous Systems Analytics written by Jyotsna Kumar Mandal and published by Springer Nature. This book was released on 2021-11-27 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents high-quality research papers presented at International Conference on Applications of Networks, Sensors and Autonomous Systems Analytics (ICANSAA 2020), held during December, 11 – 12, 2020, at JIS College of Engineering, Kalyani, West Bengal, India. The major topics covered are cyber-physical systems and sensor networks, data analytics and autonomous systems and MEMS and NEMS with applications in biomedical devices. It includes novel and innovative work from experts, practitioners, scientists, and decision-makers from academia and industry.

Download or read book Principles of Data Mining written by Max Bramer and published by Springer. This book was released on 2016-11-09 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explains and explores the principal techniques of Data Mining, the automatic extraction of implicit and potentially useful information from data, which is increasingly used in commercial, scientific and other application areas. It focuses on classification, association rule mining and clustering. Each topic is clearly explained, with a focus on algorithms not mathematical formalism, and is illustrated by detailed worked examples. The book is written for readers without a strong background in mathematics or statistics and any formulae used are explained in detail. It can be used as a textbook to support courses at undergraduate or postgraduate levels in a wide range of subjects including Computer Science, Business Studies, Marketing, Artificial Intelligence, Bioinformatics and Forensic Science. As an aid to self study, this book aims to help general readers develop the necessary understanding of what is inside the 'black box' so they can use commercial data mining packages discriminatingly, as well as enabling advanced readers or academic researchers to understand or contribute to future technical advances in the field. Each chapter has practical exercises to enable readers to check their progress. A full glossary of technical terms used is included. This expanded third edition includes detailed descriptions of algorithms for classifying streaming data, both stationary data, where the underlying model is fixed, and data that is time-dependent, where the underlying model changes from time to time - a phenomenon known as concept drift.

Download or read book Acoustic Emission Testing written by Christian U. Grosse and published by Springer Science & Business Media. This book was released on 2008-07-12 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic Emission (AE) techniques have been studied in civil engineering for a long time. The techniques are recently going to be more and more applied to practical applications and to be standardized in the codes. This is because the increase of aging structures and disastrous damages due to recent earthquakes urgently demand for maintenance and retrofit of civil structures in service for example. It results in the need for the development of advanced and effective inspection techniques. Thus, AE techniques draw a great attention to diagnostic applications and in material testing. The book covers all levels from the description of AE basics for AE beginners (level of a student) to sophisticated AE algorithms and applications to real large-scale structures as well as the observation of the cracking process in laboratory specimen to study fracture processes.

Download or read book High Voltage Engineering Fundamentals written by John Kuffel and published by Elsevier. This book was released on 2000-07-17 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power transfer for large systems depends on high system voltages. The basics of high voltage laboratory techniques and phenomena, together with the principles governing the design of high voltage insulation, are covered in this book for students, utility engineers, designers and operators of high voltage equipment. In this new edition the text has been entirely revised to reflect current practice. Major changes include coverage of the latest instrumentation, the use of electronegative gases such as sulfur hexafluoride, modern diagnostic techniques, and high voltage testing procedures with statistical approaches. - A classic text on high voltage engineering - Entirely revised to bring you up-to-date with current practice - Benefit from expanded sections on testing and diagnostic techniques

Download or read book Fiber Optic Sensors written by Eric Udd and published by . This book was released on 2006 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation A comprehensive introduction to this fast growing technology. This book provides an introduction to the rapidly advancing and expanding field of fiber optic sensors, with chapters contributed by internationally recognized experts. Each of the three sections-Basic Components, Technology, and Applications-offers a stand-alone primer on a key area of the field. Together, they give engineers, scientists, graduate students, and advanced undergraduates a comprehensive resource on fiber optic sensors. Initial chapters cover optical fibers, light sources, and detectors and optical modulators, introducing the fundamental building blocks of fiber optic sensors and pointing out the many connections between these elements and fiber optic sensor technology. Subsequent chapters cover: Extrinsic or hybrid fiber optic sensors, Intensity sensors for monitoring temperature, position, and other environmental aspects. The Fabry-Perot based fiber optic sensor. The Mach-Zehnder interferometer, The Sagnac interferometer and fiber gyroscopes. Displacement fiber optic sensors. Polarization sensors. Industrial applications of fiber optic sensors. Fiber optic smart structures. Pooling the expertise of leading professionals, Fiber Optic Sensors supplies an integral resource for understanding a key area of optical science and telecommunications.

Download or read book The Science and Applications of Acoustics written by Daniel R. Raichel and published by Springer Science & Business Media. This book was released on 2006-01-04 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook treats the broad range of modern acoustics from the basics of wave propagation in solids and fluids to applications such as noise control and cancellation, underwater acoustics, music and music synthesis, sonoluminescence, and medical diagnostics with ultrasound. The new edition is up-to-date and forward-looking in approach. Additional coverage of the opto-acoustics and sonoluminescence phenomena is included. New problems have been added throughout.