9,980 research outputs found

    An Integrated DC Series Arc Fault Detection Method for Different Operating Conditions

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    Support vector machine based classification in condition monitoring of induction motors

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    Continuous and trouble-free operation of induction motors is an essential part of modern power and production plants. Faults and failures of electrical machinery may cause remarkable economical losses but also highly dangerous situations. In addition to analytical and knowledge-based models, application of data-based models has established a firm position in the induction motor fault diagnostics during the last decade. For example, pattern recognition with Neural Networks (NN) is widely studied. Support Vector Machine (SVM) is a novel machine learning method introduced in early 90's. It is based on the statistical learning theory presented by V.N. Vapnik, and it has been successfully applied to numerous classification and pattern recognition problems such as text categorization, image recognition and bioinformatics. SVM based classifier is built to minimize the structural misclassification risk, whereas conventional classification techniques often apply minimization of the empirical risk. Therefore, SVM is claimed to lead enhanced generalisation properties. Further, application of SVM results in the global solution for a classification problem. Thirdly, SVM based classification is attractive, because its efficiency does not directly depend on the dimension of classified entities. This property is very useful in fault diagnostics, because the number of fault classification features does not have to be drastically limited. However, SVM has not yet been widely studied in the area of fault diagnostics. Specifically, in the condition monitoring of induction motor, it does not seem to have been considered before this research. In this thesis, a SVM based classification scheme is designed for different tasks in induction motor fault diagnostics and for partial discharge analysis of insulation condition monitoring. Several variables are compared as fault indicators, and forces on rotor are found to be important in fault detection instead of motor current that is currently widely studied. The measurement of forces is difficult, but easily measurable vibrations are directly related to the forces. Hence, vibration monitoring is considered in more detail as the medium for the motor fault diagnostics. SVM classifiers are essentially 2-class classifiers. In addition to the induction motor fault diagnostics, the results of this thesis cover various methods for coupling SVMs for carrying out a multi-class classification problem.reviewe

    NASA SBIR abstracts of 1990 phase 1 projects

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    The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number

    Intelligent Low Voltage Series Arc Detection System

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    Protection from electric power hazardous has been used ever since applications of electricity were discovered. Hazards in the electric system can be in the form of over voltage or over current leading to catastrophic system and equipment failure, resulting in physical damage or even to human fatalities. Electrical protection is achieved by installing protection devices throughout distribution system to isolate faulty branches and mitigate fault development. Fire is a principal cause of buildings damages and related personal injuries. A major contributor to buildings’ fire originates from electrical arc faults caused by electric distribution equipment and appliances failures. To remedy this problem, regulatory bodies required electric arc faults protection. Over the years this requirement was enforced by different electric codes and expanded to cover most of residential building areas and all living spaces. Arc fault circuit interrupters (AFCI) are devised to complement existing protection methodologies and devices, focusing on electric arc detection and preventions of subsequent risks, mainly fire ignition. Circuit interruption occurs whenever characteristics of arc failure is detected, either from current, voltage or electromagnetic radiation. Detecting the arc faults, and hence increasing the reliability of interruption, is a challenge, given that some household appliances produce arc-like behaviors in normal operating conditions, like electronic light dimmers and solid state controlled variable speed drives. This research focuses on developing an intelligent low voltage series arcing detection scheme based on pattern recognition, with immunity to false tripping. This point is the main drawback of most published work and issued patents on arc detection to date, mainly due to the difficulty of modelling such a transient behavior, especially on low current arc cases. Real data is generated in lab simulating series arc conditions at different combinations of linear and non-linear loads. Appliances current are recorded as well. Two disjoint datasets are used for training and testing of the proposed system with no components shared between the two datasets to verify classifier generality. The proposed pattern recognition method proved to be highly immune to false tripping in line with benchmark regulatory standard, and can be adapted to similar hard to model non-stationary problems

    Application of advanced technology to space automation

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    Automated operations in space provide the key to optimized mission design and data acquisition at minimum cost for the future. The results of this study strongly accentuate this statement and should provide further incentive for immediate development of specific automtion technology as defined herein. Essential automation technology requirements were identified for future programs. The study was undertaken to address the future role of automation in the space program, the potential benefits to be derived, and the technology efforts that should be directed toward obtaining these benefits

    Arc fault detection using artificial intelligence: Challenges and benefits

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    This systematic review aims to investigate recent developments in the area of arc fault detection. The rising demand for electricity and concomitant expansion of energy systems has resulted in a heightened risk of arc faults and the likelihood of related fires, presenting a matter of considerable concern. To address this challenge, this review focuses on the role of artificial intelligence (AI) in arc fault detection, with the objective of illuminating its advantages and identifying current limitations. Through a meticulous literature selection process, a total of 63 articles were included in the final analysis. The findings of this review suggest that AI plays a significant role in enhancing the accuracy and speed of detection and allowing for customization to specific types of faults in arc fault detection. Simultaneously, three major challenges were also identified, including missed and false detections, the restricted application of neural networks and the paucity of relevant data. In conclusion, AI has exhibited tremendous potential for transforming the field of arc fault detection and holds substantial promise for enhancing electrical safety

    Signal Processing and Robust Statistics for Fault Detection in Photovoltaic Arrays

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    abstract: Photovoltaics (PV) is an important and rapidly growing area of research. With the advent of power system monitoring and communication technology collectively known as the "smart grid," an opportunity exists to apply signal processing techniques to monitoring and control of PV arrays. In this paper a monitoring system which provides real-time measurements of each PV module's voltage and current is considered. A fault detection algorithm formulated as a clustering problem and addressed using the robust minimum covariance determinant (MCD) estimator is described; its performance on simulated instances of arc and ground faults is evaluated. The algorithm is found to perform well on many types of faults commonly occurring in PV arrays. Among several types of detection algorithms considered, only the MCD shows high performance on both types of faults.Dissertation/ThesisM.S. Electrical Engineering 201

    Machine learning approach to detect arc faults based on regular coupling features

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    During AC series arc faults (SAFs), arcing current features can change or vanish under different conditions. The phenomena make it challenging to detect SAFs. To address the issues, this paper presents a detection model based on regular coupling features (RCFs). After the model is only trained by the samples in single-load circuits, it can detect SAFs under unknown multi-load circuits. To extract RCFs, asymmetric magnetic flux is coupled by passing the live line and the neutral line through the current transformer. According to the unique signals, two time-domain features and one frequency-domain feature are extracted to represent RCFs, including impulse -factor analysis, covariance-matrix analysis and multiple frequency-band analysis. Then, the impulse factor and its threshold are used to preprocess the signals and decrease analysis complexity for the classifier. Finally, the experimental results show that the proposed method has significantly improved generalization ability and detection accuracy in SAF detection

    A Review on Application of Artificial Intelligence Techniques in Microgrids

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    A microgrid can be formed by the integration of different components such as loads, renewable/conventional units, and energy storage systems in a local area. Microgrids with the advantages of being flexible, environmentally friendly, and self-sufficient can improve the power system performance metrics such as resiliency and reliability. However, design and implementation of microgrids are always faced with different challenges considering the uncertainties associated with loads and renewable energy resources (RERs), sudden load variations, energy management of several energy resources, etc. Therefore, it is required to employ such rapid and accurate methods, as artificial intelligence (AI) techniques, to address these challenges and improve the MG's efficiency, stability, security, and reliability. Utilization of AI helps to develop systems as intelligent as humans to learn, decide, and solve problems. This paper presents a review on different applications of AI-based techniques in microgrids such as energy management, load and generation forecasting, protection, power electronics control, and cyber security. Different AI tasks such as regression and classification in microgrids are discussed using methods including machine learning, artificial neural networks, fuzzy logic, support vector machines, etc. The advantages, limitation, and future trends of AI applications in microgrids are discussed.©2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed
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