Download or read book On line Non intrusive Partial Discharges Detection in Aeronautical Systems written by Cédric Abadie and published by . This book was released on 2017 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of power electronics in recent years has led to increase power density and to decrease pulse width modulation (PWM) voltage inverter cost. These developments have expanded the use of power converters for variable speed drive applications which enabled the development of the concept of "more electric aircraft". This concept consists in replacing one of energy carriers (pneumatic or hydraulic) with electrical energy. However, the deployment of electrical energy has increased the onboard voltage, which leads to premature aging of onboard electrical equipment. The shape of the PWM voltage consists of pulse trains. With the application of these pulses, the voltage is no longer homogeneously distributed along the coil. In this case, large differences in potential between the strands are present. In addition, another important parameter derived from the winding type motor used in industry. The random winding is the most common technique for low voltage motors due to its lower cost. The risk generated by this type of winding is that the first and the last turns of the first coil can be facing one another. In this case, up to 80% of the voltage will be supported by a few tens of microns of enamel, and existing insulation systems are not designed to withstand such severe constraints. The use of long cable connecting the inverter to the motor can also cause significant overvoltage at the motor terminals. This phenomenon is explained by the fact that the cable behaves as a transmission line to which the motor coils is not adapted in terms of impedance. In addition, these large potential differences associated with low pressures in the depressurized areas of the aircraft, may cause the occurrence of partial discharge. Partial discharges are electrical discharges that short-circuited partially the gap between two conductors. There are many detection methods well known under AC and DC voltage, however, in the case of the detection under PWM like voltage in low-voltage motors, the detection is much more complex. Partial discharge signals are embedded in the electromagnetic noise generated by the switching. The aim of this thesis is to develop a detection method and filtering method enabling a non-intrusive and an "on-line" partial discharges detection in the aeronautical field in order to qualify the electrical insulation systems used in aircraft.
Download or read book On line Partial Discharges Detection in Conversion Systems Used in Aeronautics written by Benjamin Cella and published by . This book was released on 2015 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: The more electrical airplane concept led industrial companies to focus a part of their efforts on risks linked to the use of high voltage in a severe environment (Low pressure, wide range of temperature and humidity ...). Associated risks are the existence and the growing of partial discharges ultimately leading to the breakdown of the system in which they occur. Considering this problematic, the Liebherr Elektronik GmbH group, in collaboration with the Laplace laboratory, launched the study of a method allowing partial discharges detection in converters intended to be used in aeronautical applications. The results of this work are the subject of this thesis. The first part brings the status of the current knowledge about partial discharges from their physical nature to the detection methods which are used. In the second part, three measurement phases assessing the efficiency of the studied method are introduced and their results discussed. Finally, in the third part, the conclusionsof our works and their perspectives are presented.
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 Partial Discharge Detection for Evaluation of Insulation Integrity in Aerospace Electric Power System Wiring and Components Postprint written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report was developed under a SBIR contract. The paper describes the importance of partial discharge (PD) detection for aerospace electric power system wiring and components in low pressure environment. The relationships between recorded discharge pulse current waveforms and PD electrical characteristics are explained and discussed. Features of a new PD analyzer for low pressure applications are reviewed.
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 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 Detection and Classification of Partial Discharge Sources Under Variable Frequency and Air Pressure written by Ali Nasr Esfahani and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the development of electrical apparatus in more-electric aircraft (MEA), demand for higher electric power is increasing rapidly. In turn, this requires a higher voltage level in the power generation system of aircraft which increases the electric stress on the insulation systems. At higher voltages, the insulation systems of more-electric aircraft are prone to partial discharge (PDs) initiation under the operating condition. The objective of this thesis is to perform a comprehensive study on developing diagnostic methods for the insulation condition monitoring and PD source identification. An algorithm is developed based on the combination of wavelet and energy techniques to detect the PD pulses from the measured noisy PD signals. In addition, based on the statistical distributions of PD pulse waveform characteristics, a classification and separation algorithm is developed for the identification of multi-source PDs using kernel support vector machine (KSVM) as the classifier. The experimental results show that the proposed algorithms show a high performance and accuracy for PD source detection and recognition.
Download or read book Partial Discharge Detection and Analysis in Low Pressure Environments written by Xin Liu and published by . This book was released on 2006 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Typical aerospace vehicles (aircraft and spacecraft) experience a wide range of operating pressures during ascending and returning to earth. Compared to the sea-level atmospheric pressure (760 Torr), the pressure at about 60 km altitude is 2 Torr. The performance of the electric power system components of the aerospace vehicles must remain reliable even under such sub-atmospheric operating conditions. It is well known that the dielectric strength of gaseous insulators, while the electrode arrangement remains unchanged, is pressure dependent. Therefore, characterization of the performance and behavior of the electrical insulation in flight vehicles in low-pressure environments is extremely important. Partial discharge testing is one of the practical methods for evaluating the integrity of electrical insulation in aerospace vehicles. This dissertation describes partial discharge (PD) measurements performed mainly with 60 Hz ac energization in air, argon and helium, for pressures between 2 and 760 Torr. Two main electrode arrangements were used. One was a needle-plane electrode arrangement with a Teflon insulating barrier. The other one was a twisted pair of insulated conductors taken from a standard aircraft wiring harness. The measurement results are presented in terms of typical PD current pulse waveforms and waveform analysis for both main electrode arrangements. The evaluation criteria are the waveform polarity, magnitude, shape, rise time, and phase angle (temporal location) relative to the source voltage. Two-variable histograms and statistical averages of the PD parameters are presented. The PD physical mechanisms are analyzed. For PD pattern recognition, both statistical methods (such as discharge parameter dot pattern representation, discharge parameter phase distribution, statistical operator calculations, and PD fingerprint development) and wavelet transform applications are investigated. The main conclusions of the dissertation include: (1) The PD current pulse waveforms are dependent on the pressure. (2) The rise time of the waveform is another effective PD current pulse characteristic indicator. (3) PD fingerprint patterns that are already available for atmospheric pressure (760 Torr) conditions are inadequate for the evaluation of PD pulses at low pressures. (4) Various wavelet transform techniques can be used effectively for PD pulse signal denoising purposes, and for PD pulse waveform transient feature recognition.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Review of Federal Programs for Wire System Safety written by National Science and Technology Council (U.S.). Wire System Safety Interagency Working Group and published by . This book was released on 2000 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technology for Large Space Systems written by and published by . This book was released on 1990 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to IEEE Publications written by Institute of Electrical and Electronics Engineers and published by . This book was released on 1998 with total page 1270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues for 1973- cover the entire IEEE technical literature.
Download or read book Fiber Optic Sensors and Systems written by and published by Information Gatekeepers Inc. This book was released on with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Leak Detection written by Stuart Hamilton and published by IWA Publishing. This book was released on 2013-06-30 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ageing infrastructure and declining water resources are major concerns with a growing global population. Controlling water loss has therefore become a priority for water utilities around the world. In order to improve efficiencies, water utilities need to apply good practices in leak detection. Leak Detection: Technology and Implementation assists water utilities with the development and implementation of leak detection programs. Leak detection and repair is one of the components of controlling water loss. In addition, techniques are discussed within this book and relevant case studies are presented. This book provides useful and practical information on leakage issues.
Download or read book Official Gazette of the United States Patent and Trademark Office written by and published by . This book was released on 1975 with total page 2308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index of Specifications and Standards written by and published by . This book was released on 2005 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
