Pub Date : 1994-07-03DOI: 10.1109/ICPADM.1994.414068
Y. Purushottam, K. Udayakumar, K. Dharmalingam
It has been identified that highly humid operating conditions known as 'aggravated service conditions' are one of the contributory factors in the degradation of organic insulation in medium voltage switchgear components. This paper quantifies the deterious effects of relative humidity and voltage stress on the behavior of Bisphenol epoxy resin cast switchgear components. Short term and long term endurance tests were conducted using loss factor and leakage current as degradation parameters. The data generated is used to develop a generalised system model to predict the endurance of epoxy resin cast equipment under humid conditions.<>
{"title":"Characterisation of epoxy resin bushings under aggravated service conditions","authors":"Y. Purushottam, K. Udayakumar, K. Dharmalingam","doi":"10.1109/ICPADM.1994.414068","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.414068","url":null,"abstract":"It has been identified that highly humid operating conditions known as 'aggravated service conditions' are one of the contributory factors in the degradation of organic insulation in medium voltage switchgear components. This paper quantifies the deterious effects of relative humidity and voltage stress on the behavior of Bisphenol epoxy resin cast switchgear components. Short term and long term endurance tests were conducted using loss factor and leakage current as degradation parameters. The data generated is used to develop a generalised system model to predict the endurance of epoxy resin cast equipment under humid conditions.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115463603","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 : 1994-07-03DOI: 10.1109/ICPADM.1994.413980
L. Martinu, J. Klemberg-Sapieha, M. Wertheimer
Dual-mode microwave/radiofrequency PECVD processes have been used for the fabrication of four types of amorphous dielectric films: SiN/sub 1.3/, SiO/sub 2/, a-C:H, and plasma-polymerized hexamethyldisiloxane (PP-HMDSO). For each of these materials, we have determined values of the critical average ion energy E~/sub i/ (between about 70 and 170 eV) and of the critical ion flux, which characterize the transition from a porous to a densely packed microstructure, at low (/spl sim/25/spl deg/C) substrate temperature T/sub s/ and high deposition rates (between 20 and 120 /spl Aring//s). When E~/sub i/ values are optimized, the d.c. resistivity and the dielectric loss tangent values for all of these dielectrics are found to be about 10/sup 16/ /spl Omega/ cm and 10/sup -3/, respectively. We present evidence which shows that E~/sub i/ and T/sub s/ can be considered as interchangeable process parameters. Large area scale-up and continuous deposition onto flexible substrate materials are also discussed.<>
{"title":"Dual-frequency plasma deposition of high quality insulating thin films","authors":"L. Martinu, J. Klemberg-Sapieha, M. Wertheimer","doi":"10.1109/ICPADM.1994.413980","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.413980","url":null,"abstract":"Dual-mode microwave/radiofrequency PECVD processes have been used for the fabrication of four types of amorphous dielectric films: SiN/sub 1.3/, SiO/sub 2/, a-C:H, and plasma-polymerized hexamethyldisiloxane (PP-HMDSO). For each of these materials, we have determined values of the critical average ion energy E~/sub i/ (between about 70 and 170 eV) and of the critical ion flux, which characterize the transition from a porous to a densely packed microstructure, at low (/spl sim/25/spl deg/C) substrate temperature T/sub s/ and high deposition rates (between 20 and 120 /spl Aring//s). When E~/sub i/ values are optimized, the d.c. resistivity and the dielectric loss tangent values for all of these dielectrics are found to be about 10/sup 16/ /spl Omega/ cm and 10/sup -3/, respectively. We present evidence which shows that E~/sub i/ and T/sub s/ can be considered as interchangeable process parameters. Large area scale-up and continuous deposition onto flexible substrate materials are also discussed.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121030968","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 : 1994-07-03DOI: 10.1109/ICPADM.1994.414031
M. Fujii, K. Arii, K. Yoshino
Impulse trees in insulators have been measured three-dimensionally to investigate their development mechanism. Since a usually observed tree is a projected one on the plane, the projected tree has pretend branches and the directions of its branches are not exact. In this paper, the impulse trees in the polymeric insulator (PMMA) have been measured three-dimensionally utilizing a CT (computer tomography) method. Successive impulse voltages have been applied. In each step, the tree has been measured and also the properties of the tree which cannot be obtained by the projected tree, such as the cross section. The volume and the distribution of the branches have been obtained for both polarities.<>
{"title":"Development of tree in polymeric insulator applied successive impulse voltages and its three-dimensional measurement","authors":"M. Fujii, K. Arii, K. Yoshino","doi":"10.1109/ICPADM.1994.414031","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.414031","url":null,"abstract":"Impulse trees in insulators have been measured three-dimensionally to investigate their development mechanism. Since a usually observed tree is a projected one on the plane, the projected tree has pretend branches and the directions of its branches are not exact. In this paper, the impulse trees in the polymeric insulator (PMMA) have been measured three-dimensionally utilizing a CT (computer tomography) method. Successive impulse voltages have been applied. In each step, the tree has been measured and also the properties of the tree which cannot be obtained by the projected tree, such as the cross section. The volume and the distribution of the branches have been obtained for both polarities.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124933688","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 : 1994-07-03DOI: 10.1109/ICPADM.1994.414090
B. Phung, R. James, D. Krcho
This paper presents the application of a computerised discharge analyser (CDA3) in characterising a number of possible insulation fault conditions in oil-impregnated systems. The behaviour of discharge activity due to the presence of small metal particles, moisture ingress, sparking and tracking was investigated.<>
{"title":"Application of a computer-based partial discharge measurement system (CDA3) for identifying possible insulation fault conditions","authors":"B. Phung, R. James, D. Krcho","doi":"10.1109/ICPADM.1994.414090","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.414090","url":null,"abstract":"This paper presents the application of a computerised discharge analyser (CDA3) in characterising a number of possible insulation fault conditions in oil-impregnated systems. The behaviour of discharge activity due to the presence of small metal particles, moisture ingress, sparking and tracking was investigated.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125465319","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 : 1994-07-03DOI: 10.1109/ICPADM.1994.414034
F. Zong-Huai, N. Yoshimura, M. Yanagiwara
So far, there is no general agreement on the microstructure of water trees, and two models have been proposed. In one model, it is considered that a water tree consists of continuous paths such as microchannels, while in the other model it is taken into account that a water tree is composed of a number of microcavities which are not connected. In this paper, AgNO/sub 3/ (silver nitrate) solution was used as needle electrode to grow water trees in polyethylene. It was found that during the formation of water trees, silver ions, due to having low free energy of oxidation and reduction, are reduced into metallic silver which is deposited in the channels of water trees. This process is like electroplating, so the channels of water trees still remain after removal of electric field. It was observed by means of an SEM that there do exist microchannels in a water tree with their diameters being from 02 to 0.5 /spl mu/m. Based on this discovery, a possible model on the microstructure of a water tree is suggested. In this model the two models above-mentioned are unified.<>
{"title":"The research on microstructure of water trees in polyethylene","authors":"F. Zong-Huai, N. Yoshimura, M. Yanagiwara","doi":"10.1109/ICPADM.1994.414034","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.414034","url":null,"abstract":"So far, there is no general agreement on the microstructure of water trees, and two models have been proposed. In one model, it is considered that a water tree consists of continuous paths such as microchannels, while in the other model it is taken into account that a water tree is composed of a number of microcavities which are not connected. In this paper, AgNO/sub 3/ (silver nitrate) solution was used as needle electrode to grow water trees in polyethylene. It was found that during the formation of water trees, silver ions, due to having low free energy of oxidation and reduction, are reduced into metallic silver which is deposited in the channels of water trees. This process is like electroplating, so the channels of water trees still remain after removal of electric field. It was observed by means of an SEM that there do exist microchannels in a water tree with their diameters being from 02 to 0.5 /spl mu/m. Based on this discovery, a possible model on the microstructure of a water tree is suggested. In this model the two models above-mentioned are unified.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122732613","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 : 1994-07-03DOI: 10.1109/ICPADM.1994.413955
K. Suh, J. Koo, Seung Hyung Lee, Jung-Ki Park, T. Takada
The effects of low molecular weight chains of PE and chemical change during the sample preparation investigated in order to clarify the origins for heterocharge in LDPE which does not contain antioxidants. Both were found to affect the formation of space charge in LDPE. Low molecular weight chains of PE encourage the formation of heterocharge by polarization or migration mechanisms. The carbonyls formed at the surface of a LDPE sample during sample preparation reduce the heterocharge by an enhanced charge injection. The nature of the chemical change during sample preparation is also discussed in the text.<>
{"title":"Origin of heterocharge in polyethylene","authors":"K. Suh, J. Koo, Seung Hyung Lee, Jung-Ki Park, T. Takada","doi":"10.1109/ICPADM.1994.413955","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.413955","url":null,"abstract":"The effects of low molecular weight chains of PE and chemical change during the sample preparation investigated in order to clarify the origins for heterocharge in LDPE which does not contain antioxidants. Both were found to affect the formation of space charge in LDPE. Low molecular weight chains of PE encourage the formation of heterocharge by polarization or migration mechanisms. The carbonyls formed at the surface of a LDPE sample during sample preparation reduce the heterocharge by an enhanced charge injection. The nature of the chemical change during sample preparation is also discussed in the text.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122449320","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 : 1994-07-03DOI: 10.1109/ICPADM.1994.414106
M. Zahn, R. Hanaoka
Electric field distributions measured using the Kerr effect have a phase shift between light components polarized parallel and perpendicular to the electric field, which is proportional to the magnitude squared of the electric field components in the plane perpendicular to light propagation integrated over the light path length. One wishes to recover the electric field distribution from measurements of light phase shifts. For axisymmetric geometries where the electric field depends only on the radial coordinate and whose direction is constant along the light path, as is the case along a planar electrode, the total phase shift for light propagating at a constant distance from the center of symmetry and the electric field distribution are related by an Abel transform pair, a special case of Radon transforms typically used in image reconstructions with medical tomography and holography. This paper examines the Abel transformation for a point-plane electrode system and reports related preliminary Kerr electro-optic field mapping measurements in transformer oil.<>
{"title":"Kerr electro-optic measurements of transformer oil in a point-plane geometry","authors":"M. Zahn, R. Hanaoka","doi":"10.1109/ICPADM.1994.414106","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.414106","url":null,"abstract":"Electric field distributions measured using the Kerr effect have a phase shift between light components polarized parallel and perpendicular to the electric field, which is proportional to the magnitude squared of the electric field components in the plane perpendicular to light propagation integrated over the light path length. One wishes to recover the electric field distribution from measurements of light phase shifts. For axisymmetric geometries where the electric field depends only on the radial coordinate and whose direction is constant along the light path, as is the case along a planar electrode, the total phase shift for light propagating at a constant distance from the center of symmetry and the electric field distribution are related by an Abel transform pair, a special case of Radon transforms typically used in image reconstructions with medical tomography and holography. This paper examines the Abel transformation for a point-plane electrode system and reports related preliminary Kerr electro-optic field mapping measurements in transformer oil.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"386 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114503858","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 : 1994-07-03DOI: 10.1109/ICPADM.1994.414147
J.P. Patelli, A. Audoli, J. Drommi
Electricite de France uses a large number of electric generators. Incident analyses and experience feedback enable the drawing up of rules concerning protection, monitoring and maintenance of such equipment. This experience shows the usefulness in having three monitoring levels: protection; protection-monitoring; and maintenance-monitoring. The article makes use of different examples which show that these systems must be consistent, in order to define and carry out efficient maintenance operations on electric generators.<>
{"title":"Protection, monitoring and maintenance of power generators","authors":"J.P. Patelli, A. Audoli, J. Drommi","doi":"10.1109/ICPADM.1994.414147","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.414147","url":null,"abstract":"Electricite de France uses a large number of electric generators. Incident analyses and experience feedback enable the drawing up of rules concerning protection, monitoring and maintenance of such equipment. This experience shows the usefulness in having three monitoring levels: protection; protection-monitoring; and maintenance-monitoring. The article makes use of different examples which show that these systems must be consistent, in order to define and carry out efficient maintenance operations on electric generators.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129877427","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 : 1994-07-03DOI: 10.1109/ICPADM.1994.414071
A. Levy, O. Filho, E. Forster
Partial discharges in air have been the subject of many studies. Here, a study of individual partial discharges taking place in the nanosecond range has been performed to gain more definite information on their temporal characteristics. The total charge of such a single pulse was compared with the results obtained with a commercial partial discharge measuring system. A significant difference in the total charge measured by these two systems has been found. The significance of these findings is discussed in detail. Reference is also made to the pulsating characteristics observed for the individual current signals.<>
{"title":"A study of partial discharges in air with an ultra-wideband signal detector","authors":"A. Levy, O. Filho, E. Forster","doi":"10.1109/ICPADM.1994.414071","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.414071","url":null,"abstract":"Partial discharges in air have been the subject of many studies. Here, a study of individual partial discharges taking place in the nanosecond range has been performed to gain more definite information on their temporal characteristics. The total charge of such a single pulse was compared with the results obtained with a commercial partial discharge measuring system. A significant difference in the total charge measured by these two systems has been found. The significance of these findings is discussed in detail. Reference is also made to the pulsating characteristics observed for the individual current signals.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128783129","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 : 1994-07-03DOI: 10.1109/ICPADM.1994.413932
K. Yamazawa, H. Yamashita, E. Forster
Streamer initiation and propagation processes were observed in liquid nitrogen under non-uniform field. A high magnification (63.5/spl times/), high speed (up to 50 ns/Frame) shadowgraph system was employed for the optical measurements. Under impulse voltage conditions, there were two types of negative streamer; one was a slow (10/spl sim/100 m/s) bush-like streamer and the other a filamentary one which was faster (100/spl sim/500 m/s) and grew straight or sometimes winding towards the opposite electrode. In both cases, the initial structure of the streamer appeared to be a filament. In conjunction with the optical study, current pulses were also measured simultaneously using a LED current pulse measurement system. The onset of the current pulse occurred prior to the streamer inception for both types of streamers but their frequency and amplitude were quite different.<>
{"title":"Prebreakdown phenomena in cryogenic liquids","authors":"K. Yamazawa, H. Yamashita, E. Forster","doi":"10.1109/ICPADM.1994.413932","DOIUrl":"https://doi.org/10.1109/ICPADM.1994.413932","url":null,"abstract":"Streamer initiation and propagation processes were observed in liquid nitrogen under non-uniform field. A high magnification (63.5/spl times/), high speed (up to 50 ns/Frame) shadowgraph system was employed for the optical measurements. Under impulse voltage conditions, there were two types of negative streamer; one was a slow (10/spl sim/100 m/s) bush-like streamer and the other a filamentary one which was faster (100/spl sim/500 m/s) and grew straight or sometimes winding towards the opposite electrode. In both cases, the initial structure of the streamer appeared to be a filament. In conjunction with the optical study, current pulses were also measured simultaneously using a LED current pulse measurement system. The onset of the current pulse occurred prior to the streamer inception for both types of streamers but their frequency and amplitude were quite different.<<ETX>>","PeriodicalId":331058,"journal":{"name":"Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129920885","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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