Pub Date : 1991-10-20DOI: 10.1109/CEIDP.1991.763345
A. De Reggi, S. Mahdavi, J. Lewiner, C. Alquié
We have used the pressure-wave-propagation method [l] on a microscale to measure the spatial distribution of charge in polyethylene between the point of an imbedded, voltage-biased needle electrode and a grounded, planar, counter electrode on one surface. The pulsed laser beam that produces the pressure pulses was focused on a small diameter aperture as a means of maintaining energy while reducing the diameter of the laser-induced pressure wave front. The capacitance that is modulated by the pressure wave and contributes to the response, thus is confined to that small volume swept-out by the pressure wave within which the injected charge is expected to reside. Reducing unwanted capacitance modulations from regions outside this volume is the dynamic equivalent of electrostatically guarding the needle point when measuring injection currents from the point [2]. In the present work and in [2], the charge injected from the point is rendered observable. Guarding is of limited usefulness when studying injection near breakdown because, if the guard is grounded, the distance from the needle point to the guard cannot be made much smaller than the distance between the point and the ground plane, while, if the guard is at the needle potential, it too may be a source of injected charge.
{"title":"Experimental Determination Of The Development And Evolution Of The Spatial Distribution Of Charge Injected In Polyethylene By A Voltage-biased Needle","authors":"A. De Reggi, S. Mahdavi, J. Lewiner, C. Alquié","doi":"10.1109/CEIDP.1991.763345","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763345","url":null,"abstract":"We have used the pressure-wave-propagation method [l] on a microscale to measure the spatial distribution of charge in polyethylene between the point of an imbedded, voltage-biased needle electrode and a grounded, planar, counter electrode on one surface. The pulsed laser beam that produces the pressure pulses was focused on a small diameter aperture as a means of maintaining energy while reducing the diameter of the laser-induced pressure wave front. The capacitance that is modulated by the pressure wave and contributes to the response, thus is confined to that small volume swept-out by the pressure wave within which the injected charge is expected to reside. Reducing unwanted capacitance modulations from regions outside this volume is the dynamic equivalent of electrostatically guarding the needle point when measuring injection currents from the point [2]. In the present work and in [2], the charge injected from the point is rendered observable. Guarding is of limited usefulness when studying injection near breakdown because, if the guard is grounded, the distance from the needle point to the guard cannot be made much smaller than the distance between the point and the ground plane, while, if the guard is at the needle potential, it too may be a source of injected charge.","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121485766","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 : 1991-10-20DOI: 10.1109/CEIDP.1991.763335
T. Mizutani, Y. Suzuoki, M. Hikita, Han Sang Ok, Kim Jong Seuk
Polyethylene (PE) is one of the most important and widelystudied polymers because of its good electrical properties (high resistivity and low tan 6 ) and also because of its s imple chemical structure. Its electrical properties have been studied by many reserchers these tens years. Recently, much attention has been paid to the effects of oxidation on electrical properties of PE. Many papers have been published on the effects of oxidation o n high field conduction[l ,2], space charge[3,4], treeing breakdown[5,6] of PE. However, their details are not so well understood yet.
{"title":"High Field Conduction And Breakdown Of Polyethylene - Oxidation Effects","authors":"T. Mizutani, Y. Suzuoki, M. Hikita, Han Sang Ok, Kim Jong Seuk","doi":"10.1109/CEIDP.1991.763335","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763335","url":null,"abstract":"Polyethylene (PE) is one of the most important and widelystudied polymers because of its good electrical properties (high resistivity and low tan 6 ) and also because of its s imple chemical structure. Its electrical properties have been studied by many reserchers these tens years. Recently, much attention has been paid to the effects of oxidation on electrical properties of PE. Many papers have been published on the effects of oxidation o n high field conduction[l ,2], space charge[3,4], treeing breakdown[5,6] of PE. However, their details are not so well understood yet.","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122425067","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 : 1991-10-20DOI: 10.1109/CEIDP.1991.763962
A. Bruning, M. Danikas
{"title":"Observations on discharges above and below CIV in polymer insulation","authors":"A. Bruning, M. Danikas","doi":"10.1109/CEIDP.1991.763962","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763962","url":null,"abstract":"","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115881461","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 : 1991-10-20DOI: 10.1109/CEIDP.1991.763354
G. Mohamed, T. Horvath
In the study of insulating systems, the analysis of the dielectric losses and relaxation phenomena is an interesting instrument to appreciate the status of the material and the variations on medium composition due to aging effects. In this paper a computer simulation of the behavior of dielectric constant, and loss factor against the frequency and temperature is presented. At first, from the experimental data of insulation materials and taking into consideration a distribution function of relaxation times, a mathematical or an empirical distribution function for each material can be assumed. An optimized computer program has been used to calculate the distribution parameters. Also, the dependence of these parameters on the aging processes, e.g. temperature, oxidat ion will be discussed. Finally, comparison between the calculated complex dielectric constants, will be found to be in good agreement with the experimental values.
{"title":"Computer simulation of dielectric relaxation phenomena","authors":"G. Mohamed, T. Horvath","doi":"10.1109/CEIDP.1991.763354","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763354","url":null,"abstract":"In the study of insulating systems, the analysis of the dielectric losses and relaxation phenomena is an interesting instrument to appreciate the status of the material and the variations on medium composition due to aging effects. In this paper a computer simulation of the behavior of dielectric constant, and loss factor against the frequency and temperature is presented. At first, from the experimental data of insulation materials and taking into consideration a distribution function of relaxation times, a mathematical or an empirical distribution function for each material can be assumed. An optimized computer program has been used to calculate the distribution parameters. Also, the dependence of these parameters on the aging processes, e.g. temperature, oxidat ion will be discussed. Finally, comparison between the calculated complex dielectric constants, will be found to be in good agreement with the experimental values.","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116780797","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 : 1991-10-20DOI: 10.1109/CEIDP.1991.763377
E. Moreau, C. Mayoux, C. Laurent
{"title":"Dielectric Properties Of A Unique Water Tree In Polyethylene Samples","authors":"E. Moreau, C. Mayoux, C. Laurent","doi":"10.1109/CEIDP.1991.763377","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763377","url":null,"abstract":"","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"164 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126744404","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 : 1991-10-20DOI: 10.1109/CEIDP.1991.763863
S. Itahashi, M. Sono, H. Mitsui
1 .Introduction Generally it is known that water in liquid dielectrics influence to electrical conduction and breakdown phenomena. Such water in dielectrics has been understood that they behaved as the carrier with electrical charge sometimes or the conduction bridge sometimes. In the past studies on conduction of liquid insulators, it is doubtful whether dissolved water can be measured completely or not. Still more the state of water in liquid dielectrics can not be measured by Karl Fisher’s method also. Because Karl Fisher’s Method which use chemical reaction can not measure whole water in liquid and their state always. Therefore the relation between the amount of the water and the electrical phenomena had not been clearly. On the other hand the observing method of state and agglomeration of water has been published by chemical researchers as the result measured by Near Infra Red Ray(N1R) or Infra Red Ray(1R) Method. At the region IR, it has been published that the agglomeration of the water classified into Monomer, Dimmer, Trimmer((H20)1,(H20)2,(H20)3 or n). In this paper, using FT-IR Method and Karl Fisher’s Method the state and agglomeration of water and the amount of water in several kinds of liquid materials are measured. And using amount of the Monomer, Dimmer and Trimmer measured by FT-IR Method under electrical stress, the relation between the water in these liquids and conduction are discussed. At the result, it is seen that the conduction in the liquids depend on amount of Dimmer except Silicon Oils which consist of polymeric structure. And, at the case of Silicon Oils the increasing Dimmer which is little part of whole Dimmer influence to conduction phenomena.
{"title":"Effect of dissolved water in several kinds of liquid dielectrics on conduction","authors":"S. Itahashi, M. Sono, H. Mitsui","doi":"10.1109/CEIDP.1991.763863","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763863","url":null,"abstract":"1 .Introduction Generally it is known that water in liquid dielectrics influence to electrical conduction and breakdown phenomena. Such water in dielectrics has been understood that they behaved as the carrier with electrical charge sometimes or the conduction bridge sometimes. In the past studies on conduction of liquid insulators, it is doubtful whether dissolved water can be measured completely or not. Still more the state of water in liquid dielectrics can not be measured by Karl Fisher’s method also. Because Karl Fisher’s Method which use chemical reaction can not measure whole water in liquid and their state always. Therefore the relation between the amount of the water and the electrical phenomena had not been clearly. On the other hand the observing method of state and agglomeration of water has been published by chemical researchers as the result measured by Near Infra Red Ray(N1R) or Infra Red Ray(1R) Method. At the region IR, it has been published that the agglomeration of the water classified into Monomer, Dimmer, Trimmer((H20)1,(H20)2,(H20)3 or n). In this paper, using FT-IR Method and Karl Fisher’s Method the state and agglomeration of water and the amount of water in several kinds of liquid materials are measured. And using amount of the Monomer, Dimmer and Trimmer measured by FT-IR Method under electrical stress, the relation between the water in these liquids and conduction are discussed. At the result, it is seen that the conduction in the liquids depend on amount of Dimmer except Silicon Oils which consist of polymeric structure. And, at the case of Silicon Oils the increasing Dimmer which is little part of whole Dimmer influence to conduction phenomena.","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124874200","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 : 1991-10-20DOI: 10.1109/CEIDP.1991.763954
R. V. Van Brunt, E. W. Cernyar
{"title":"Influence Of Phase-to-phase Memory Propagation On The Stochastic Behavior of Ac-generated Partial Discharges","authors":"R. V. Van Brunt, E. W. Cernyar","doi":"10.1109/CEIDP.1991.763954","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763954","url":null,"abstract":"","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121842197","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 : 1991-10-20DOI: 10.1109/CEIDP.1991.763942
M. Duval, H. Dupas, F. Langdeau, P. Gervais, G. Bélanger
Dissolved-gas analysis (DGA) has been used extensively over the last 20 years to detect incipient faults in high-voltage transformers. The early warning it provides often allows corrective measures to be taken before catastrophic failure occurs. Based on the relative proportions of the gases formed, several DG-4 interpretation methods are available for identification of the fault (arcing, corona or hot spots) [l-41. The concentration levels at which the identified faults can be considered acceptable or dangerous in service are more controversial, however. Recent studies show that the probability norms currently used for that purpose are not very reliable and an alternative method based on the actual probability of failure in service has been developed [5, 81. Acceptable and dangerous gas levels in transformers thus appear t o be significantly influenced by the type of fault involved as well as by the type and age of the equipment. The general trends are that safe levels are lower for arcing than for hot spots, in the early and late years of the equipment, and for sealed instrument transformers rather than power transformers. Cellulose participation in the fault, as indicated by the CO/COZ ratio, also reduces the safe level of dissolved CzH4 in power transformers. In the present work, the influence of instrument transformer type (current vs voltage equipment) is examined.
{"title":"Acceptable Gas-in-oil Levels In Instrument Transformers (current Vs Voltage Equipement)","authors":"M. Duval, H. Dupas, F. Langdeau, P. Gervais, G. Bélanger","doi":"10.1109/CEIDP.1991.763942","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763942","url":null,"abstract":"Dissolved-gas analysis (DGA) has been used extensively over the last 20 years to detect incipient faults in high-voltage transformers. The early warning it provides often allows corrective measures to be taken before catastrophic failure occurs. Based on the relative proportions of the gases formed, several DG-4 interpretation methods are available for identification of the fault (arcing, corona or hot spots) [l-41. The concentration levels at which the identified faults can be considered acceptable or dangerous in service are more controversial, however. Recent studies show that the probability norms currently used for that purpose are not very reliable and an alternative method based on the actual probability of failure in service has been developed [5, 81. Acceptable and dangerous gas levels in transformers thus appear t o be significantly influenced by the type of fault involved as well as by the type and age of the equipment. The general trends are that safe levels are lower for arcing than for hot spots, in the early and late years of the equipment, and for sealed instrument transformers rather than power transformers. Cellulose participation in the fault, as indicated by the CO/COZ ratio, also reduces the safe level of dissolved CzH4 in power transformers. In the present work, the influence of instrument transformer type (current vs voltage equipment) is examined.","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121495878","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 : 1991-10-20DOI: 10.1109/CEIDP.1991.763951
H. Yamada, K. Tamada, T. Fujiwara, T. Sato
The electrical breakdown phenomena in mixtures of cyclohexane and carbon tetrachloride for point-to-plane gap configuration have been investigated using a microsecond rectangular high-voltage pulse generator. The high speed photography reveals that the aspect of negative streamer development is similar to that of positive one when the mole fraction of carbon tetrachloride is more than 1%. The more precise time lag to breakdown was directly measured from prebreakdown current. The streamer propagation velocity is estimated from the linear relation to formative time lag and gap spacing. The streamer velocity for a negative point in cyclohexane is exceedingly increased by a small amount of carbon tetrachloride as additive, more so than that for a positive point.
{"title":"Steamer propagation and breakdown time lag in mixtures of cyclohexane and carbon tetrachloride","authors":"H. Yamada, K. Tamada, T. Fujiwara, T. Sato","doi":"10.1109/CEIDP.1991.763951","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763951","url":null,"abstract":"The electrical breakdown phenomena in mixtures of cyclohexane and carbon tetrachloride for point-to-plane gap configuration have been investigated using a microsecond rectangular high-voltage pulse generator. The high speed photography reveals that the aspect of negative streamer development is similar to that of positive one when the mole fraction of carbon tetrachloride is more than 1%. The more precise time lag to breakdown was directly measured from prebreakdown current. The streamer propagation velocity is estimated from the linear relation to formative time lag and gap spacing. The streamer velocity for a negative point in cyclohexane is exceedingly increased by a small amount of carbon tetrachloride as additive, more so than that for a positive point.","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124680943","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 : 1991-10-20DOI: 10.1109/CEIDP.1991.763338
T. Asokan, T. Sudarshan
A novel electrode system is designed and validated to facilitate time- coordinated electrical and optical measurements of surface discharges a insulators. The investigation is performed on polycrystalline Al/sub 2/O/sub 3/ and single crystal quartz by employing the new electrode and the conventional parallel plane electrode systems. The results obtained by using the two electrode systems are compared and discussed. The single crystal quartz specimens found to exhibit higher breakdown strengths (-350 KV/cm) compared to polycrystalline alumina (-230 kV/cm).
{"title":"Validation Of A Novel Electrode System To Study The Surface Flashover Behavior of Insulators","authors":"T. Asokan, T. Sudarshan","doi":"10.1109/CEIDP.1991.763338","DOIUrl":"https://doi.org/10.1109/CEIDP.1991.763338","url":null,"abstract":"A novel electrode system is designed and validated to facilitate time- coordinated electrical and optical measurements of surface discharges a insulators. The investigation is performed on polycrystalline Al/sub 2/O/sub 3/ and single crystal quartz by employing the new electrode and the conventional parallel plane electrode systems. The results obtained by using the two electrode systems are compared and discussed. The single crystal quartz specimens found to exhibit higher breakdown strengths (-350 KV/cm) compared to polycrystalline alumina (-230 kV/cm).","PeriodicalId":277387,"journal":{"name":"1991 Annual Report. Conference on Electrical Insulation and Dielectric Phenomena,","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116578824","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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