Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464430
J. Crine, M. Duval, C. Lamarre
Oil from transformers under normal service load was analyzed by several techniques in order to determine the degree of aging and the best aging evaluation method. The interfacial tension was found to vary with the antioxidant concentration but it is also affected by exposure to daylight, which implies that samples should be measured without too long a delay. Carbonyl and polar groups were determined by IR and HPLC, respectively. The dissolved capper content in the oil, which modifies the tan o values, was determined by neutron activation analysis. Tan δ and dielectric breakdown are not really conclusive tests because of their sensitivity to contamination. The best techniques to evaluate the aging of transformer oil, and to predict its lifetime, are interfacial tension and antioxidant concentration (above 100–150 ppm) measurements and HPLC analysis for lower concentrations.
{"title":"Evaluation of transformer oil aging under service load from various chemical and dielectric measurements","authors":"J. Crine, M. Duval, C. Lamarre","doi":"10.1109/EIC.1982.7464430","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464430","url":null,"abstract":"Oil from transformers under normal service load was analyzed by several techniques in order to determine the degree of aging and the best aging evaluation method. The interfacial tension was found to vary with the antioxidant concentration but it is also affected by exposure to daylight, which implies that samples should be measured without too long a delay. Carbonyl and polar groups were determined by IR and HPLC, respectively. The dissolved capper content in the oil, which modifies the tan o values, was determined by neutron activation analysis. Tan δ and dielectric breakdown are not really conclusive tests because of their sensitivity to contamination. The best techniques to evaluate the aging of transformer oil, and to predict its lifetime, are interfacial tension and antioxidant concentration (above 100–150 ppm) measurements and HPLC analysis for lower concentrations.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134252619","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}
Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464488
R. Meyrueix, M. Pétriat, R. Tobazéon
The physico-chemical processes involved in the gassing of dielectric liquids are studied with a uniform field test cell containing a disc-shaped gaseous bubble. When a constant AC voltage is applied to the cell, there is a time-evolution of discharges which depends on the nature of the liquid, the gas, and of the operating procedure. For gas absorbing liquids it is possible to define and derive a gas absorbing coefficient G as the ratio of molecules absorbed by the gas per unit time to the number of electrons involved in the discharge per unit time. The proposed method allows a quantitative measurement of G to be made, and a comparison of different liquids. The influence of various parameters such as temperature, liquid viscosity, gas bubble thickness is studied and discussed. As expected, voltage amplitude and frequency have no influence upon G. Possible mechanisms of gassing are considered, and a tentative classification of liquids is proposed.
{"title":"On the gassing of dielectric liquids","authors":"R. Meyrueix, M. Pétriat, R. Tobazéon","doi":"10.1109/EIC.1982.7464488","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464488","url":null,"abstract":"The physico-chemical processes involved in the gassing of dielectric liquids are studied with a uniform field test cell containing a disc-shaped gaseous bubble. When a constant AC voltage is applied to the cell, there is a time-evolution of discharges which depends on the nature of the liquid, the gas, and of the operating procedure. For gas absorbing liquids it is possible to define and derive a gas absorbing coefficient G as the ratio of molecules absorbed by the gas per unit time to the number of electrons involved in the discharge per unit time. The proposed method allows a quantitative measurement of G to be made, and a comparison of different liquids. The influence of various parameters such as temperature, liquid viscosity, gas bubble thickness is studied and discussed. As expected, voltage amplitude and frequency have no influence upon G. Possible mechanisms of gassing are considered, and a tentative classification of liquids is proposed.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128548511","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}
Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464474
B. Pratt
The selection of polymeric materials for use in high voltage insulators for outdoor applications has been based, historically, on individually developed evaluation methods.
用于户外应用的高压绝缘体的聚合物材料的选择历来是基于单独开发的评估方法。
{"title":"Evaluation methods for polymeric insulation systems in a high voltage, outdoor environment","authors":"B. Pratt","doi":"10.1109/EIC.1982.7464474","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464474","url":null,"abstract":"The selection of polymeric materials for use in high voltage insulators for outdoor applications has been based, historically, on individually developed evaluation methods.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129522419","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}
Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464441
E. Husain, R. Nema
When voids are fully enclosed in insulation, the inception of partial discharges is affected by the walls of voids. We have measured the discharge inception at different pressures below atmospheric pressure and shown the effect of pressure for different d/t′ (void diameter/void depth) which is used as a parameter of void dimensions. When d/t′ increases, there is a limiting case beyond which the discharge inception voltage Vi is similar to open voids. The rate of increase of Vi depends on the void diameter. At relatively low pressures the discharge inception is not much affected by void dimensions and this can be attributed to the fact that in this range of pt′ (pressure × void depth), the breakdown voltage of gas changes slowly. The observations are useful in understanding discharges in the insulation system of cables, capacitors, bushings or epoxy cast equipment which are dried and impregnated at low pressures containing gas pockets at sub-atmospheric pressures. The studies are also important for high altitude insulation design and spacecraft insulation.
{"title":"Discharges at low pressures in dielectric voids","authors":"E. Husain, R. Nema","doi":"10.1109/EIC.1982.7464441","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464441","url":null,"abstract":"When voids are fully enclosed in insulation, the inception of partial discharges is affected by the walls of voids. We have measured the discharge inception at different pressures below atmospheric pressure and shown the effect of pressure for different d/t′ (void diameter/void depth) which is used as a parameter of void dimensions. When d/t′ increases, there is a limiting case beyond which the discharge inception voltage Vi is similar to open voids. The rate of increase of Vi depends on the void diameter. At relatively low pressures the discharge inception is not much affected by void dimensions and this can be attributed to the fact that in this range of pt′ (pressure × void depth), the breakdown voltage of gas changes slowly. The observations are useful in understanding discharges in the insulation system of cables, capacitors, bushings or epoxy cast equipment which are dried and impregnated at low pressures containing gas pockets at sub-atmospheric pressures. The studies are also important for high altitude insulation design and spacecraft insulation.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117181222","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}
Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464423
G. Montanari, G. Pattini, L. Simoni
The results of life tests carried out up to break down of specimens are influenced by quality of the manufacture technique and by the specimen size.
在试样破裂之前进行的寿命试验结果受制造技术质量和试样尺寸的影响。
{"title":"The electric strength measurement for aging evaluation in multiple stress test","authors":"G. Montanari, G. Pattini, L. Simoni","doi":"10.1109/EIC.1982.7464423","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464423","url":null,"abstract":"The results of life tests carried out up to break down of specimens are influenced by quality of the manufacture technique and by the specimen size.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"348 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122764849","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}
Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464480
D. Jolly
A test method has been developed to evaluate the outdoor durability of polymer high voltage insulators. The surface discharges responsible for aging are reproduced as accurately as possible in a test chamber while specially designed microprocessor instrumentation continuously monitors the electrical behavior of the test specimens. Erosion rates can be determined in units of weight loss per coulomb of discharge activity for simple specimen shapes. Practical insulator shapes can also be tested. Combining the indoor test results with short term results from a microprocessor monitored outdoor test rack yields an estimate for the outdoor lifetime of commercial insulator designs.
{"title":"A test method for determining the outdoor lifetime of polymer overhead transmission line insulators","authors":"D. Jolly","doi":"10.1109/EIC.1982.7464480","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464480","url":null,"abstract":"A test method has been developed to evaluate the outdoor durability of polymer high voltage insulators. The surface discharges responsible for aging are reproduced as accurately as possible in a test chamber while specially designed microprocessor instrumentation continuously monitors the electrical behavior of the test specimens. Erosion rates can be determined in units of weight loss per coulomb of discharge activity for simple specimen shapes. Practical insulator shapes can also be tested. Combining the indoor test results with short term results from a microprocessor monitored outdoor test rack yields an estimate for the outdoor lifetime of commercial insulator designs.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130801393","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}
Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464438
J. B. Lynch
It is important to emphasize that in D.C. Partial Discharge Testing, visual interpretation of the pulses on the detector screen must be replaced by the Pulse Height Analyzer. This type analysis will reduce or eliminate the operator's subjective interpretation of the detector while improving productivity and maintaining consistent test evaluation of the specimen.
{"title":"Partial discharge testing using the pulse height analyzer","authors":"J. B. Lynch","doi":"10.1109/EIC.1982.7464438","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464438","url":null,"abstract":"It is important to emphasize that in D.C. Partial Discharge Testing, visual interpretation of the pulses on the detector screen must be replaced by the Pulse Height Analyzer. This type analysis will reduce or eliminate the operator's subjective interpretation of the detector while improving productivity and maintaining consistent test evaluation of the specimen.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122107751","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}
Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464444
R. Lee, T. Sudarshan, J. Thompson, G. Nagabhushana
Predischarge current measurements, for a solid insulator bridged vacuum gap excited by 60 Hz AC, are reported here. To our knowledge it is for the first time that such results are published in the literature. The predischarge current in a plane vacuum gap is known to follow the Fowler-Nordheim type emission when subjected to DC voltages [1,2]. The studies are rather limited for AC voltages and the current is believed to follow a modified ion field emission [3,4]. The results presented in this work indicate that the plane vacuum gap predischarge current is modified by the presence of the insulating spacer. The modification of the current characteristics is believed to be caused by the charging of the insulator surface due to secondary electron emission from it. It is shown that the steady predischarge current can be reduced to a small value or eliminated, and the breakdown voltage increased, by reducing the stress at the triple junction either (a) by interposing a high permittivity material such as barium titanate between the spaeer and each of the electrodes, or (b) by shielding the triple junctions within recessed electrodes. The purpose of these experiments is to see if there is a correlation between prebreakdown currents and (a) the insulator surface charging, (b) the breakdown strength. The insulator shape and the secondary emission yield from its surface also affect the predischarge current characteristics, and these results will be published in the future.
{"title":"Prebreakdown conduction measurments in vacuum gaps with alumina insulators","authors":"R. Lee, T. Sudarshan, J. Thompson, G. Nagabhushana","doi":"10.1109/EIC.1982.7464444","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464444","url":null,"abstract":"Predischarge current measurements, for a solid insulator bridged vacuum gap excited by 60 Hz AC, are reported here. To our knowledge it is for the first time that such results are published in the literature. The predischarge current in a plane vacuum gap is known to follow the Fowler-Nordheim type emission when subjected to DC voltages [1,2]. The studies are rather limited for AC voltages and the current is believed to follow a modified ion field emission [3,4]. The results presented in this work indicate that the plane vacuum gap predischarge current is modified by the presence of the insulating spacer. The modification of the current characteristics is believed to be caused by the charging of the insulator surface due to secondary electron emission from it. It is shown that the steady predischarge current can be reduced to a small value or eliminated, and the breakdown voltage increased, by reducing the stress at the triple junction either (a) by interposing a high permittivity material such as barium titanate between the spaeer and each of the electrodes, or (b) by shielding the triple junctions within recessed electrodes. The purpose of these experiments is to see if there is a correlation between prebreakdown currents and (a) the insulator surface charging, (b) the breakdown strength. The insulator shape and the secondary emission yield from its surface also affect the predischarge current characteristics, and these results will be published in the future.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128810197","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}
Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464432
K. Goto, S. Kojima, K. Oguni
This paper describes experiments which were conducted to determine the optimum composition of fiberglass reinforced plastic for tracking resistance. The evaluation of tracking resistance was conducted by the inclined plane method and a long-term accelerated voltage test under wet and contaminated conditions. Results show that the components having the greater effect on tracking resistance are glass fiber, aluminum trihydrate and thermoplastic polymer used as an anti-shrinking agent. Correlation between the inclined plane method and the long-term accelerated voltage test can be noted.
{"title":"Improved formulation for tracking resistance and long-term accelerated degradation of fiberglass reinforced plastics","authors":"K. Goto, S. Kojima, K. Oguni","doi":"10.1109/EIC.1982.7464432","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464432","url":null,"abstract":"This paper describes experiments which were conducted to determine the optimum composition of fiberglass reinforced plastic for tracking resistance. The evaluation of tracking resistance was conducted by the inclined plane method and a long-term accelerated voltage test under wet and contaminated conditions. Results show that the components having the greater effect on tracking resistance are glass fiber, aluminum trihydrate and thermoplastic polymer used as an anti-shrinking agent. Correlation between the inclined plane method and the long-term accelerated voltage test can be noted.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121354607","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}
Pub Date : 1982-06-07DOI: 10.1109/EIC.1982.7464431
R. Bozzo, L. Centurioni, G. Coletti
Electrical apparatuses for indoor use are often equipped with insulating components made by organic materials, which can be subjected to particular ambient conditions leading to a situation similar to the one experienced in outdoor conditions, but, obviously, leas severe.
{"title":"Behaviour of insulating organic materials for indoor use under A.C. voltage in artificially polluted atmosphere","authors":"R. Bozzo, L. Centurioni, G. Coletti","doi":"10.1109/EIC.1982.7464431","DOIUrl":"https://doi.org/10.1109/EIC.1982.7464431","url":null,"abstract":"Electrical apparatuses for indoor use are often equipped with insulating components made by organic materials, which can be subjected to particular ambient conditions leading to a situation similar to the one experienced in outdoor conditions, but, obviously, leas severe.","PeriodicalId":422317,"journal":{"name":"1982 IEEE International Conference on Electrical Insulation","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128743583","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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