The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
N. I. Khoroshev - One of the best experts on this subject based on the ideXlab platform.
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Diagnostics of the Power Oil-filled transformer equipment of thermal Power plants
Thermal Engineering, 2016Co-Authors: D. K. Eltyshev, N. I. KhoroshevAbstract:Problems concerning improvement of the diagnostics efficiency of the electrical facilities and functioning of the generation and distribution systems through the examples of the Power Oil-filled transformers, as the responsible elements referring to the electrical part of thermal Power plants (TPP), were considered. Research activity is based on the fuzzy logic system allowing working both with statistical and expert information presented in the form of knowledge accumulated during operation of the Power Oil-filled transformer facilities. The diagnostic algorithm for various types of transformers, with the use of the intellectual estimation model of its thermal state on the basis of the key diagnostic parameters and fuzzy inference hierarchy, was developed. Criteria for taking measures allowing preventing emergencies in the electric Power systems were developed. The fuzzy hierarchical model for the state assessment of the Power Oil-filled transformers of 110 kV, possessing high degree of credibility and setting quite strict requirements to the limits of variables of the equipment diagnostic parameters, was developed. The most frequent defects of the transformer standard elements, related with the disturbance of the isolation properties and instrumentation operation, were revealed after model testing on the real object. Presented results may be used both for the express diagnostics of the transformers state without disconnection from the Power line and for more detailed analysis of the defects causes on the basis of the advanced list of the diagnostic parameters; information on those parameters may be received only after complete or partial disconnection.
D. K. Eltyshev - One of the best experts on this subject based on the ideXlab platform.
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Diagnostics of the Power Oil-filled transformer equipment of thermal Power plants
Thermal Engineering, 2016Co-Authors: D. K. Eltyshev, N. I. KhoroshevAbstract:Problems concerning improvement of the diagnostics efficiency of the electrical facilities and functioning of the generation and distribution systems through the examples of the Power Oil-filled transformers, as the responsible elements referring to the electrical part of thermal Power plants (TPP), were considered. Research activity is based on the fuzzy logic system allowing working both with statistical and expert information presented in the form of knowledge accumulated during operation of the Power Oil-filled transformer facilities. The diagnostic algorithm for various types of transformers, with the use of the intellectual estimation model of its thermal state on the basis of the key diagnostic parameters and fuzzy inference hierarchy, was developed. Criteria for taking measures allowing preventing emergencies in the electric Power systems were developed. The fuzzy hierarchical model for the state assessment of the Power Oil-filled transformers of 110 kV, possessing high degree of credibility and setting quite strict requirements to the limits of variables of the equipment diagnostic parameters, was developed. The most frequent defects of the transformer standard elements, related with the disturbance of the isolation properties and instrumentation operation, were revealed after model testing on the real object. Presented results may be used both for the express diagnostics of the transformers state without disconnection from the Power line and for more detailed analysis of the defects causes on the basis of the advanced list of the diagnostic parameters; information on those parameters may be received only after complete or partial disconnection.
Dj. Kalić - One of the best experts on this subject based on the ideXlab platform.
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Results of a novel algorithm for the calculation of the characteristic temperatures in Power Oil transformers
Electrical Engineering, 1997Co-Authors: Z. Radaković, Dj. KalićAbstract:The application of the originally developed thermal model, intended to Oil Power transformers analyses, is presented in the paper. The model delivers the value of the insulation Hot-spot temperature, as the most critical quantity during transformer loading, and the value of the thermal ageing, both for variable load and variable ambient temperature. The results obtained using the original thermal model are compared with the experimental results and the results obtained by the model from the international standard IEC 354. A program is developed for this purpose, allowing some additional analysis in respect to the basic algorithm from IEC 354. Besides, using experimentally obtained results, some approximations of the thermal model from IEC 354 and some factors important for development of thermal models are also analyzed. Das Thema dieses Beitrages ist die Anwendung eines von uns neuentwickelten thermischen Modells zur Analyse von Öltransformatoren. Das Modell liefert den Temperaturwert der Isolation an der heißesten Stelle, welches während der Belastung des Transformators der kritischste Wert ist, sowie die Werte der thermischen Alterung des Transformators, beides unter veränderlicher Belastung und Umgebungstemperatur. Die Ergebnisse unseres Modells werden mit Experimentaluntersuchungen und mit den Resultaten des Modells IEC Standard 354 verglichen. Dafür wurde ein Rechenprogramm ausgearbeitet, das größere Möglichkeiten zur Analyse als das Grundmodell Standard 354 hat. Schließlich werden einige Vereinfachungen für das IEC-Modell vorgeschlagen und wichtige Faktoren, die während der thermischen Modellentwicklungen auftreten analysiert.
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Results of a novel algorithm for the calculation of the characteristic temperatures in Power Oil transformers
Electrical Engineering, 1997Co-Authors: Zoran Radakovic, Dj. KalićAbstract:The application of the originally developed thermal model, intended to Oil Power transformers analyses, is presented in the paper. The model delivers the value of the insulation Hot-spot temperature, as the most critical quantity during transformer loading, and the value of the thermal ageing, both for variable load and variable ambient temperature. The results obtained using the original thermal model are compared with the experimental results and the results obtained by the model from the international standard IEC 354. A program is developed for this purpose, allowing some additional analysis in respect to the basic algorithm from IEC 354. Besides, using experimentally obtained results, some approximations of the thermal model from IEC 354 and some factors important for development of thermal models are also analyzed.
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On the determination of characteristic temperatures in Power Oil transformers during transient states
Archiv für Elektrotechnik, 1993Co-Authors: Dj. Kalić, Z. Radaković, Z. Lazarević, R. RadosavljevićAbstract:Die Gleichungen des Temperaturverhaltens eines Transformators werden unter den üblichen Annahmen aufgestellt. Es werden Algorithmen entwickelt, welche die Vorausbestimmung der Temperatur an kritischen Stellen bei nichtstationärem Betrieb erlauben. Vorgeschlagen wird die Bestimmung der temperaturabhängigen und-unabhängigen Parameter auf Grund von wenigen und einfachen Messungen. Damit kann das Personal in Verteilerstationen in die Lage versetzt werden, mit Hilfe von PC's die Belastung der Transformatoren bis zu den zulässigen Grenztemperaturen auszudehnen. Die Autoren möchten damit einen Anstoß zu einer möglichen Überarbeitung von IEC-Vorschriften geben. Under usual assumptions the equations describing thermal phenomena in a transformer are established. Without neglecting any substantially important factor, algorithms are developed for predicting the temperatures in critical spots in non-stationary states occurring either in practice or in load/time diagrams. This paper suggests the determinaton of conductances dependent on temperature and constant capacitances of equivalent thermal circuits of a transformer. They are based on a small number of experiments (as simple as possible) and on a parameter estimation procedure. In such a way the temperatures of transformer parts in different transient states can be determined by computer simulation established on equivalent circuits, so the operators in Power and sub-stations will be able to load their transformers close to the permitted limit. It is felt that this paper may give a stimulation for a possible revision of IEC rules.
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On the determination of characteristic temperatures in Power Oil transformers during transient states
Archiv für Elektrotechnik, 1993Co-Authors: Dj. Kalić, Z. Radaković, Z. Lazarević, R. RadosavljevićAbstract:Under usual assumptions the equations describing thermal phenomena in a transformer are established. Without neglecting any substantially important factor, algorithms are developed for predicting the temperatures in critical spots in non-stationary states occurring either in practice or in load/time diagrams. This paper suggests the determinaton of conductances dependent on temperature and constant capacitances of equivalent thermal circuits of a transformer. They are based on a small number of experiments (as simple as possible) and on a parameter estimation procedure. In such a way the temperatures of transformer parts in different transient states can be determined by computer simulation established on equivalent circuits, so the operators in Power and sub-stations will be able to load their transformers close to the permitted limit. It is felt that this paper may give a stimulation for a possible revision of IEC rules.
Danda B. Rawat - One of the best experts on this subject based on the ideXlab platform.
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Editorial:Industrial Internet: Security, Architectures, and Technologies
IEEE Transactions on Industrial Informatics, 2020Co-Authors: Qing Yang, Reza Malekian, C. Wang, Danda B. RawatAbstract:Industrial Internet is applicable across a broad industrial spectrum including manufacturing, aviation, road and rail transport, Power, Oil and gas, healthcare, smart cities and buildings. Some of the major impacts of the Industrial Internet include the development of new and innovative services and products, which in turn also has economic benefits. The purpose of this special issue is to bring together research studies proposing novel techniques, algorithms, models, and solutions to address challenges such as interoperability, security, and privacy associated with Industrial Internet, blockchain and Cyber-physical systems.
Karin Göhler - One of the best experts on this subject based on the ideXlab platform.
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Modern vacuum pumps for the vacuum degassing of steel in small and large vacuum-degassing units
Metallurgist, 2013Co-Authors: W. Burgmann, Karin GöhlerAbstract:This article discusses a new design for Roots pumps and screw pumps which uses hermetically sealed motors. The new pump is easy to maintain, alleviates wear, and increases safety, which makes it more reliable than traditional Roots pumps. The screw vacuum pumps operate within a wide range of pressures. Thanks to the absence of friction in the vacuum chamber and the use of special coatings on the working elements, these units can be used in place of water-ring and rotary vane pumps for the high-vacuum evacuation of gases and vapors of liquids (including aggressive liquids). In this case, the gas being pumped is not contaminated by water vapor or Oil. The absence of friction elements in the vacuum chamber means that the unit requires almost no maintenance. The use of standardized pre-equipped modular building blocks reduces fabrication and installation/startup costs, makes the equipment more compact, and saves Power, Oil, and water compared to other systems. The small size of both types of pumps - which can be used in any configuration - not only shortens delivery times and simplifies spare-parts management but also facilitates equipment assembly or (if necessary) replacement. Attainment of the pumps' rated productivity is assured by parallel connection of several compact modules. The mechanical pumps can be used for VID, VIM, VD, RH, VIT (vacuum ingot teeming), and VAR (vacuum-arc remelting) units, including units that perform vacuum-oxygen decarburization. The pumps' design incorporates measures to protect against dust and water-vapor condensation, which can lead to the formation of acidic liquids. The pumps can be used in all types of vacuum processes - including processes that involve the injection of oxygen - while observing existing safety standards. The low inertial mass of the pumps helps them respond rapidly to frequency control, which facilitates the evacuation process. Redundant operation is provided for in all the pumping-unit configurations. [ABSTRACT FROM AUTHOR]