Download or read book Partial Discharge Diagnostics in Medium Voltage Cables written by Faisal Peer Mohamed and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the high voltage cables installed in the United Kingdom for power transmission and distribution are approaching the end of their designed life. This is likely to lead to an increased prevalence of circuit faults resulting directly from insulation degradation and breakdown due to ageing. This will lead to customer interruption and regulatory penalties. A program for the wholesale replacement of vast cable networks is impracticable, not economically viable and most likely unnecessary. A more pragmatic and affordable approach to extending the life time of these ageing assets, incorporating targeted cable replacement, may be achieved through the use ofcondition based maintenance strategies utilizing online partial discharge monitoring technologies. Partial discharges (PD) are the early symptoms of insulation degradation that can ultimately lead to complete breakdown of the insulation system.Presented in this thesis are novel contributions to the area of online PD diagnostics for underground medium voltage cables. The work encompasses various issues with installation of PD sensors in cable networks, data acquisition procedures and signal processing techniques for post processing of PD data. A novel approach of using power frequency current transformer for detecting PD is proposed. This approach is validated using laboratory tests and on-site trials using the PD monitoring hardware developed. PD source location using double ended method is widely accepted due to theaccuracy in discharge site location compare to single ended approach. However, this method is not widely used due to its complex system design, time synchronization and communication requirement between measurement units at both ends of the cable network. In this thesis, double ended PD source location system using a novel time based triggering logic is implemented in field programmable gate arrays with GPS. System design, laboratory results and on-site trials are presented. Denoising of PD signals using second generation wavelet transform are comparatively faster than classical wavelet based techniques. This second generation wavelet transform using kurtosis based thresholding is developed and tested using synthetic and on-site data. A PD signal interpretation algorithm is applied to analyse the data acquired from the 11kV PILC cable network from 33/11kV substation using the system developed.

Download or read book Partial Discharge Detection and Diagnostics Using Double sided Measurement written by Jichao Chen and published by . This book was released on 2014 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Partial discharge detection and diagnostics have always been the major concerns of power cable quality evaluation. Based on the review of published literatures and the systems currently available on market, this ME thesis has proposed a new mathematical algorithm for double-sided PD measurement, which removes earth noise from the collected PD signals and localises the PD sources. This developed algorithm generally is comprised of wavelet de-noising, time domain reflectometry, time-of-arrival estimation and very low frequency cable testing criteria. It has been implemented on LabVIEW platform. PD signals are acquired by USB-5133 and then process through the algorithm. This system has a graphical user interface which is able to give users results of the de-noised signals from two cable ends and readings about the PD source location. This system has been tested at both signal and medium voltage levels. Signal level tests give results as expected that it has the minimum errors when the PDs occur near the centre of the cable and vice versa. It performs well for the PD signals with signal-to-noise ratio no less than 9.70 dB. Medium voltage level tests do not give sufficient results due to radiation phenomenon between two cable ends. However, by analysing the waveforms, it partially verifies the integrity of the developed system.

Download or read book Online Partial Discharge Detection and Signal Analysis for High Voltage Cables written by David Ming Hui Foo and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Partial Discharges are symptoms of insulation degradation that continually promotes the deterioration of the insulation condition, eventually leading to permanent failures. The PD event itself is not dangerous but it is the state of the discharge activity that can lead to unforeseen failures. Hence continuous monitoring of PD enables the prevention of these unforeseen failures that result in economic losses. High voltage equipment that has been installed more than forty years ago is highly susceptible to PD since it is reaching the insulation end life. For the case of underground cables, continuous PD monitoring will help avoid unplanned outages and the need for the immediate replacement of faulty cable sections that will incur large costs. Traditionally, PD diagnostics have been carried out through offline methods, whereby the cable specimen is removed from service during the diagnostic tests. On the other hand, online PD diagnostics are preferable since the services are not disrupted. However, there are some major challenges that come with the online approach. For instance, heavy noise interference, the detection and location of PD through the interpretation of measured signals. Presented in this Thesis are presented novel contributions to the area of online PD detection for underground HV cables. The work encompasses aspects of physical data acquisition procedures and the post-processing signal processing algorithms. A new online PD data acquisition unit equipped with pre-processing and signal conditioning is presented. The system has other features that take into account the difficulties of logistics as well as issues related to the regulations and protocols of the utility. The primary aim of this developed system is to produce a PD database that will be used for research purposes. Since applied wavelets for the field of PD diagnostics have been popular amongst researchers, it was investigated further in this Thesis. Following from the data acquisition system, large data sizes required intensive processing. A new wavelet-based algorithm combined with the use of Higher Order Statistics is presented. This algorithm enables the simplification of data signals to highlight potential PD activity resulting in the reduction of manual examination of wavelet algorithms. The conventional wavelet algorithms applied in the literature generally referred to a specific approach of the wavelet implementation i. e. the decimated approach. However, it was found that the non-decimated approach has several advantages with regards to PD signature detection and PD location. The application of both approaches and their comparisons is applied to simulated data as well as online field data. Finally, the analysis of online PD data acquired from the new data acquisition system is presented. Several PD characterisation processes are applied and positive results were generated. Aspects relating to the physical environments of test site are also included. The challenges and experiences gathered in this research project are described.

Download or read book An Investigation Into Partial Discharge Activity Within Three phase Belted Cables written by J. A. Hunter and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Industrially driven interest in the field of partial discharge (PD) diagnostics has rapidly increased in recent years. Utilities are turning to continuous asset monitoring methods to inform them on the real-time health of plant. The majority of London's medium voltage (MV) distribution network is constructed from paper insulated lead covered (PILC) belted cables. The vast majority of this cable was commissioned in the 60's and 70's and is now nearing the end of its design life. PD diagnostics have been proposed as a possible tool for the condition monitoring of these distribution cables. Little is known about the characteristics of the PD activity that is produced as cables of this design degrade under rated conditions. This thesis describes the development of a PD measurement experiment that records PD data from either defective or damaged three-phase MV PILC cables under rated voltage conditions. The experiment has been designed to replicate the environment experienced by cable circuits in the field. The aim was to investigate the potential transfer of knowledge generated by the experiment onto an on-line commercial operational system. An investigation into the PD produced by the various degradation mechanisms have been undertaken to evaluate the relationship between the PD source conditions and recorded signals. It has been found that the phase-resolved PD patterns produced by different degradation mechanisms are unique. Consequently, a PD source discrimination technique has been successfully applied to both experiment and field data. The algorithm relies on the finding that the wavelet energy (WE) distribution of a PD pulse is source dependent. A support vector machine (SVM) was used to accurately classify PD pulses from different sources that had been tested experimentally. The ability to accurately discriminate between different PD sources in both experiment and field data should lead to a significant step forward in the field of PD diagnostics.

Download or read book Partial Discharge Detection in High voltage Equipment written by F. H. Kreuger and published by Butterworth-Heinemann. This book was released on 1989 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of current knowledge of electrical discharges that do not completely bridge the electrodes. Discharge detection, since 1945 and the use of new high voltage dielectrics, has grown into an indispensable tool for the evaluation of modern insulation. Topics covered include the behavior, detection and measurement of discharges, the choice of detection method and procedure, the location of discharges, and discharge detection in practice. Acidic paper. Annotation copyrighted by Book News, Inc., Portland, OR

Download or read book High Voltage Measurement Techniques written by Klaus Schon and published by Springer. This book was released on 2019-07-04 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book conveys the theoretical and experimental basics of a well-founded measurement technique in the areas of high DC, AC and surge voltages as well as the corresponding high currents. Additional chapters explain the acquisition of partial discharges and the electrical measured variables. Equipment exposed to very high voltages and currents is used for the transmission and distribution of electrical energy. They are therefore tested for reliability before commissioning using standardized and future test and measurement procedures. Therefore, the book also covers procedures for calibrating measurement systems and determining measurement uncertainties, and the current state of measurement technology with electro-optical and magneto-optical sensors is discussed.

Download or read book Practical Partial Discharge Measurement on Electrical Equipment written by Greg C. Stone and published by John Wiley & Sons. This book was released on 2023-10-03 with total page 581 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical Partial Discharge Measurement on Electrical Equipment Accessible reference dealing with (partial discharge) PD measurement in all types of high voltage equipment using modern digital PD detectors Practical Partial Discharge Measurement on Electrical Equipment is a timely update in the field of partial discharges (PD), covering both holistic concepts and specific modern applications in one volume. The first half of the book educates the reader on what PD is and the general principles of how it is measured and interpreted. The second half of the book is similar to a handbook, with a chapter devoted to PD measurements in each type of high voltage (HV) equipment. These chapters contain specific information of the insulation system design, causes of PD in that equipment, off-line and on-line measurement methods, interpretation methods, and relevant standards. The work is authored by four well-known experts in the field of PD measurement who have published hundreds of technical papers on the subject and performed thousands of PD measurements on all the different types of HV equipment covered in the book. The authors have also had relationships with PD detector manufacturers, giving them key insights into test instruments and practical measurements. Sample topics covered in the work include: Physics of PD, discharge phenomena (contact sparking and vibration sparking), and an introduction to PD measurement (electrical, optical, acoustic, and chemical) Electrical PD detection (types of sensors), RF PD detection (antenna, TEV), and PD instrumentation and display Off-line and on-line PD measurements, general principles of PD interpretation, and laboratory PD testing of lumped test objects PD in different types of HV equipment (power cables, power transformers, air insulated metal-clad switchgear, rotating machines, gas-insulated switchgear, and more) For HV equipment OEMs, users of HV equipment, or employees of companies that provide PD testing services to clients, Practical Partial Discharge Measurement on Electrical Equipment is an essential reference to help understand general concepts about the topic and receive expert guidance during specific practical applications.

Download or read book Partial Discharge Denoising for Power Cables written by Jiajia Liu and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Partial discharge (PD) diagnostics is considered a major and effective tool for the monitoring of insulating conditions of power cables. As such, a large amount of off-line or online PD measurements have been deployed in power cables during the past decades. However, challenges still exist in PD diagnostics for power cables. Noise is one of the challenges involved in PD measurement. This thesis develops new algorithms based on the characteristics of both PD signals and noise to improve the effectiveness of wavelet-based PD denoising. In the meantime, it presents new findings in the application of empirical mode decomposition (EMD) in PD denoising. Wavelet-based technique has received high attention in the area of PD denoising, it still faces challenges, however, in wavelet selection, decomposition scale determination, and noise estimation. It is therefore the first area of interest in this thesis to improve the effectiveness of existing wavelet-based technique in PD detection by incorporating proposed algorithms. These new algorithms were developed based on the difference of entropy between transformed PD signals and noise, and the sparsity of transformed PD signals corrupted by noise. One concern commonly expressed by critics of wavelet-based technique is a pre-defined wavelet is applied in wavelet-based technique. EMD is an algorithm that can decompose a signal based on the signal itself. Thus, the second area of interest in this thesis is to further investigate the application of EMD in PD denoising; a technique that does not require the selection of a pre-defined signal to represent the "unknown" signal of interest. A new method for relative mode selection (RMS) was proposed based on the entropy of each intrinsic mode function (IMF). Although this new method cannot outperform the existing ones, it reveals that RMS is not as important as claimed in the application of EMD in signal denoising. Also, PD signals, especially those with lower magnitudes, can receive serious distortion through EMD-based denoising. Finally, comparisons between wavelet-based and EMD-based denoising were implemented in the following aspects, i.e., executing time, distortion, effectiveness, adaptivity and robustness. Results unveil that improved wavelet-based technique is more preferable as it can present better performance in PD denoising.

Download or read book Partial Discharge Measurement as Diagnostic Tool for Power Cable Systems written by Bolarin Sikiru Oyegoke and published by . This book was released on 2001 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimating and Pinpointing Partial Discharge Locations on Shielded Power Cables written by Zhifang Du and published by . This book was released on 1995 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Voltage Test and Measuring Techniques written by Wolfgang Hauschild and published by Springer. This book was released on 2018-09-22 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: The new edition of this book incorporates the recent remarkable changes in electric power generation, transmission and distribution. The consequences of the latest development to High Voltage (HV) test and measuring techniques result in new chapters on Partial Discharge measurements, Measurements of Dielectric Properties, and some new thoughts on the Shannon Theorem and Impuls current measurements. This standard reference of the international high-voltage community combines high voltage engineering with HV testing techniques and HV measuring methods. Based on long-term experience gained by the authors the book reflects the state of the art as well as the future trends in testing and diagnostics of HV equipment. It ensures a reliable generation, transmission and distribution of electrical energy. The book is intended not only for experts but also for students in electrical engineering and high-voltage engineering.

Download or read book Partial Discharge Characterization of High voltage Cables and Components written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Partial Discharges PD written by Norasage Pattanadech and published by John Wiley & Sons. This book was released on 2023-07-31 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: PARTIAL DISCHARGES (PD) — DETECTION, IDENTIFICATION AND LOCALIZATION Explore state-of-the-art partial discharge measurement techniques In Partial Discharges (PD) — Detection, Identification and Localization, a team of distinguished electrical engineers delivers a comprehensive treatment of the behavior, modeling, measurement, monitoring, localization, and evaluation of partial discharges. It includes coverage of all major advancements in the field that have occurred over the last few decades. It also discusses partial discharge phenomena, detection methods, and strategies for analyzing and processing collected data. Mechanisms of insulation failure are explored, as is the denoising of partial discharge measurement data and the localization of partial discharge in large, high-voltage equipment. Non-electric principles and procedures are discussed, and the book offers a variety of tables, figures, and photographs to illustrate the concepts discussed within. Partial Discharges(PD) also provides: A thorough introduction to the physical behavior of partial discharges, including their causes and classification Comprehensive modeling of partial discharge behavior, including classical and dipole discharges Practical discussions of the measurement of partial discharges, including the electrical method, partial discharge decoupling, and pre- and post-processing of partial discharges In-depth examinations of the monitoring of partial discharge behavior, including methods and realization Perfect for electrical engineers engaged in electrical power engineering, Partial Discharges (PD) will also earn a place in the libraries of research and development specialists employed in the manufacturing, quality testing and operation of electrical systems.

Download or read book Using Online Partial Discharge Measurements to Optimise Asset Management of Medium Voltage Cable Terminations written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Partial Discharge Detection and Location on High Voltage Power Cables written by Hossein Nabi Bidhendi and published by . This book was released on 1997 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On line Signal Analysis of Partial Discharges in Medium voltage Power Cables written by Jeroen Veen and published by . This book was released on 2005 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dielectric Material written by Marius Alexandru Silaghi and published by BoD – Books on Demand. This book was released on 2012-10-03 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book attempts to bring together the theory and practice of dielectric materials for different kind of industrial applications. Fragmented information on dielectric theory and properties of materials, design of equipment and state of the art in applications relevant to the manufacturing industry should be collated and updated and presented as a single reference volume. In this book relevant and useful information is presented in the quoted literature and covered by our key patent applications.