The author points out that the application of superconductive conductors requires the development of electrical insulation capable of operating for many years at temperatures as low as 4 K and ranging to approximately 100 K for the most recent superconductors. The insulation is subjected to stresses caused by the cryogenic environment, possibly high pressures and radiation, in addition to the electrical stresses associated with service. Experimental results of aging tests for small samples are reported, and operating experiences with superconducting devices in service for about a decade are discussed. >
{"title":"The aging of electrical insulation at cryogenic temperatures","authors":"E. Forsyth","doi":"10.1109/14.237745","DOIUrl":"https://doi.org/10.1109/14.237745","url":null,"abstract":"The author points out that the application of superconductive conductors requires the development of electrical insulation capable of operating for many years at temperatures as low as 4 K and ranging to approximately 100 K for the most recent superconductors. The insulation is subjected to stresses caused by the cryogenic environment, possibly high pressures and radiation, in addition to the electrical stresses associated with service. Experimental results of aging tests for small samples are reported, and operating experiences with superconducting devices in service for about a decade are discussed. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87994337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The results of the Space Power Experiment Aboard Rockets (SPEAR) rocket series, which evaluated the effects of the space environment on high voltage (HV) insulation, are described. SPEAR I demonstrated that voltages >40 kV could be sustained in the space environment. SPEAR II ground-based simulations and tests demonstrated a number of new technologies for utilizing the properties of the space environment to reduce insulation requirements. Its results led to the construction of a reliable, lightweight, 6- to 100-kV, 1-MV pulse transformer that had significantly reduced bulk insulating media and solid insulators. A space-vacuum-insulated, lightweight, high-current storage inductor was developed which advanced the state of the art in space insulation. The SPEAR III experiment combined these developments in HV insulation technology into a comprehensive test of methods for grounding high potentials in space. >
{"title":"High voltages in space: innovation in space insulation","authors":"P. Rustan, H. Garrett, M. Schor","doi":"10.1109/14.237746","DOIUrl":"https://doi.org/10.1109/14.237746","url":null,"abstract":"The results of the Space Power Experiment Aboard Rockets (SPEAR) rocket series, which evaluated the effects of the space environment on high voltage (HV) insulation, are described. SPEAR I demonstrated that voltages >40 kV could be sustained in the space environment. SPEAR II ground-based simulations and tests demonstrated a number of new technologies for utilizing the properties of the space environment to reduce insulation requirements. Its results led to the construction of a reliable, lightweight, 6- to 100-kV, 1-MV pulse transformer that had significantly reduced bulk insulating media and solid insulators. A space-vacuum-insulated, lightweight, high-current storage inductor was developed which advanced the state of the art in space insulation. The SPEAR III experiment combined these developments in HV insulation technology into a comprehensive test of methods for grounding high potentials in space. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90935968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Khachen, J. Suthar, A. Stokes, R. Dollinger, W. Dunbar
The authors point out that aerospace electronic and power systems demand increasing levels of safety, efficiency and power delivery because of the severe effects from long term operation in the space environment, often without any manned operation or maintenance. Consequently, the design requirements place more emphasis on the insulation components and their applications, posing new challenges to the electrical insulation design engineer. The space and volume constraints require the high power components to be miniaturized, yet compatible with the thermal and mechanical environments while maintaining cost at a reasonable level. A combination of technical skills, new technologies, experience and extensive data from the older engineers is presented as the way to achieve advancement and realization of the required design specifications for the electrical insulation of aerospace systems. >
{"title":"Aerospace-specific design guidelines for electrical insulation","authors":"W. Khachen, J. Suthar, A. Stokes, R. Dollinger, W. Dunbar","doi":"10.1109/14.237748","DOIUrl":"https://doi.org/10.1109/14.237748","url":null,"abstract":"The authors point out that aerospace electronic and power systems demand increasing levels of safety, efficiency and power delivery because of the severe effects from long term operation in the space environment, often without any manned operation or maintenance. Consequently, the design requirements place more emphasis on the insulation components and their applications, posing new challenges to the electrical insulation design engineer. The space and volume constraints require the high power components to be miniaturized, yet compatible with the thermal and mechanical environments while maintaining cost at a reasonable level. A combination of technical skills, new technologies, experience and extensive data from the older engineers is presented as the way to achieve advancement and realization of the required design specifications for the electrical insulation of aerospace systems. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90672666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The authors point out that multiple-stress-induced aging occurs in all electrical equipment. However, the dominant aging mechanism may differ for each class of equipment. Electrical insulation in equipment employed by the electric utilities encompasses all types of polymers. Both thermoset and thermoplastic materials are employed. The nature of the insulation is designed to meet a variety of needs, depending on the equipment environment. For example, transformer insulation requires thermal resistance at moderate operating stresses, capacitors operate at high electrical stresses and without excessive thermal load, and cables require only moderate thermal resistance and operate at relatively low voltage stress. The utility network system, types of equipment, types of insulation used, and properties required of the electrical insulation are reviewed. The typical aging mechanism for each class of utility equipment is described, and the limits of any multifactor aging relationship's ability to predict a component's life are analyzed. >
{"title":"Aging of equipment in the electric utilities","authors":"B. Bernstein, E. Brancato","doi":"10.1109/14.237747","DOIUrl":"https://doi.org/10.1109/14.237747","url":null,"abstract":"The authors point out that multiple-stress-induced aging occurs in all electrical equipment. However, the dominant aging mechanism may differ for each class of equipment. Electrical insulation in equipment employed by the electric utilities encompasses all types of polymers. Both thermoset and thermoplastic materials are employed. The nature of the insulation is designed to meet a variety of needs, depending on the equipment environment. For example, transformer insulation requires thermal resistance at moderate operating stresses, capacitors operate at high electrical stresses and without excessive thermal load, and cables require only moderate thermal resistance and operate at relatively low voltage stress. The utility network system, types of equipment, types of insulation used, and properties required of the electrical insulation are reviewed. The typical aging mechanism for each class of utility equipment is described, and the limits of any multifactor aging relationship's ability to predict a component's life are analyzed. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89948654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The consequences of the inherent high variability of life data are described, and some objective methods to aid in the design and analysis of aging experiments are reviewed. It is argued that before accelerated aging tests and proposed aging models can acquire credibility with high-voltage (HV) equipment designers, testing of many more specimens and improved analysis methods are needed. The recent availability of sophisticated computer programs will aid in the analysis of aging data. >
{"title":"The statistics of aging models and practical reality","authors":"G. Stone","doi":"10.1109/14.237738","DOIUrl":"https://doi.org/10.1109/14.237738","url":null,"abstract":"The consequences of the inherent high variability of life data are described, and some objective methods to aid in the design and analysis of aging experiments are reviewed. It is argued that before accelerated aging tests and proposed aging models can acquire credibility with high-voltage (HV) equipment designers, testing of many more specimens and improved analysis methods are needed. The recent availability of sophisticated computer programs will aid in the analysis of aging data. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73357854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Toshikatsu Tanaka, T. Okamoto, K. Nakanishi, T. Miyamoto
Recent progress in the research and development of electrical insulation for modern electric power systems is reviewed. Cross-linked polyethylene cables, gas-insulated switchgear, composite insulators and oil-immersed transformers are covered. A number of aging processes are presented and analyzed. Typical aging processes are considered to be due to tree formation, partial discharge, electrochemical processes and thermochemical processes. Almost all causes of aging have been itemized and have been phenomenologically verified. Several other theoretical aspects that need to be clarified are identified. >
{"title":"Aging and related phenomena in modern electric power systems","authors":"Toshikatsu Tanaka, T. Okamoto, K. Nakanishi, T. Miyamoto","doi":"10.1109/14.237744","DOIUrl":"https://doi.org/10.1109/14.237744","url":null,"abstract":"Recent progress in the research and development of electrical insulation for modern electric power systems is reviewed. Cross-linked polyethylene cables, gas-insulated switchgear, composite insulators and oil-immersed transformers are covered. A number of aging processes are presented and analyzed. Typical aging processes are considered to be due to tree formation, partial discharge, electrochemical processes and thermochemical processes. Almost all causes of aging have been itemized and have been phenomenologically verified. Several other theoretical aspects that need to be clarified are identified. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78152632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effects of electrical, thermal and radiation stresses, singularly or simultaneously, on dielectric films are reviewed. The types of accelerated aging under these stresses and the statistical methods used to evaluate the experimental data for life, including the two-parameter Weibull and the log-normal distributions, are described briefly. The experimental life models currently used for aging are discussed. Recent data on the complex electrical/thermal/radiation aging of dielectric films are described. >
{"title":"Complex electrical thermal and radiation aging of dielectric films","authors":"J. Laghari","doi":"10.1109/14.237741","DOIUrl":"https://doi.org/10.1109/14.237741","url":null,"abstract":"The effects of electrical, thermal and radiation stresses, singularly or simultaneously, on dielectric films are reviewed. The types of accelerated aging under these stresses and the statistical methods used to evaluate the experimental data for life, including the two-parameter Weibull and the log-normal distributions, are described briefly. The experimental life models currently used for aging are discussed. Recent data on the complex electrical/thermal/radiation aging of dielectric films are described. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86817189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The authors review aging phenomenology and life modeling; illustrate different approaches, showing their advantages and applicability limits; and raise problems relevant to practical applications of models and evaluation of material endurance. They present the fundamentals of phenomenological aging theory and life modeling and give electrical and combined-stress life data for different materials. Electrical, thermal and multistress life models valid for insulating materials and systems, showing either linear or curvilinear behavior are presented. Particular attention is given to threshold-life models under combined thermal-electrical stresses. General aging equations for single and multiple stresses are presented, and the life surface for combined thermal-electrical stresses is introduced. Generalization to N-stress life and aging models is discussed. Statistical processing of data and determination of model parameters are mentioned, and graphical methods for material characterization are proposed. >
{"title":"Aging phenomenology and modeling","authors":"G. Montanari, L. Simoni","doi":"10.1109/14.237740","DOIUrl":"https://doi.org/10.1109/14.237740","url":null,"abstract":"The authors review aging phenomenology and life modeling; illustrate different approaches, showing their advantages and applicability limits; and raise problems relevant to practical applications of models and evaluation of material endurance. They present the fundamentals of phenomenological aging theory and life modeling and give electrical and combined-stress life data for different materials. Electrical, thermal and multistress life models valid for insulating materials and systems, showing either linear or curvilinear behavior are presented. Particular attention is given to threshold-life models under combined thermal-electrical stresses. General aging equations for single and multiple stresses are presented, and the life surface for combined thermal-electrical stresses is introduced. Generalization to N-stress life and aging models is discussed. Statistical processing of data and determination of model parameters are mentioned, and graphical methods for material characterization are proposed. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89169120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A fundamentally based chemical-thermodynamic multifactor stress aging functional relation requiring experimentally based constants is developed. The specific example presented is that of 120-V aromatic-polyimide-insulated wire. The stresses of water, temperature, and mechanical strain are included and electrical stress is considered. The results for over 2000 specimens are fitted to the theoretical trends. For a single independent variable function, the resulting relation reduces to the classical Arrhenius curve. The three independent variable relations presented here are applied to data from laboratory aging experiments that simulate insulation deterioration occurring in actual aircraft service. The results used in age categorization of US Navy aircraft are taken from wire specimens taken from active aircraft. The paradigm does not use ab initio based constants because of uncertainties in the theoretical development, two forms of which are presented. >
{"title":"Aging in wire insulation under multifactor stress","authors":"A. Bruning, F. Campbell","doi":"10.1109/14.237739","DOIUrl":"https://doi.org/10.1109/14.237739","url":null,"abstract":"A fundamentally based chemical-thermodynamic multifactor stress aging functional relation requiring experimentally based constants is developed. The specific example presented is that of 120-V aromatic-polyimide-insulated wire. The stresses of water, temperature, and mechanical strain are included and electrical stress is considered. The results for over 2000 specimens are fitted to the theoretical trends. For a single independent variable function, the resulting relation reduces to the classical Arrhenius curve. The three independent variable relations presented here are applied to data from laboratory aging experiments that simulate insulation deterioration occurring in actual aircraft service. The results used in age categorization of US Navy aircraft are taken from wire specimens taken from active aircraft. The paradigm does not use ab initio based constants because of uncertainties in the theoretical development, two forms of which are presented. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90154632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The application of three different neural networks (NNs) to the recognition of partial discharge (PD) is studied. Results of PD measurements on simple two-electrode models, as well as on models of artificial defects in industrial objects, are presented. The PDs are measured using conventional discharge detection, and PD patterns are processed by previously developed statistical tools. Mathematical descriptors are used as input patterns for a backpropagation network, Kohonen self-organizing map, and learning vector quantization network. All three NNs recognize fairly well the PD patterns of those insulation defects for which they were trained. On the other hand, the NNs could misclassify those PD patterns for which they were not trained. The classification of PD patterns by NNs can be influenced also by the structure of the particular NN, the value of the convergence criterion, and the number of learning cycles. >
{"title":"Neural networks as a tool for recognition of partial discharges","authors":"E. Gulski, A. Krivda","doi":"10.1109/14.249372","DOIUrl":"https://doi.org/10.1109/14.249372","url":null,"abstract":"The application of three different neural networks (NNs) to the recognition of partial discharge (PD) is studied. Results of PD measurements on simple two-electrode models, as well as on models of artificial defects in industrial objects, are presented. The PDs are measured using conventional discharge detection, and PD patterns are processed by previously developed statistical tools. Mathematical descriptors are used as input patterns for a backpropagation network, Kohonen self-organizing map, and learning vector quantization network. All three NNs recognize fairly well the PD patterns of those insulation defects for which they were trained. On the other hand, the NNs could misclassify those PD patterns for which they were not trained. The classification of PD patterns by NNs can be influenced also by the structure of the particular NN, the value of the convergence criterion, and the number of learning cycles. >","PeriodicalId":13105,"journal":{"name":"IEEE Transactions on Electrical Insulation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1993-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88265326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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