Pub Date : 1991-07-08DOI: 10.1109/ICPADM.1991.172180
K. Kimura, Y. Kaneda, K. Itoh
A novel mathematical approach is proposed to calculate the breakdown voltage and nondestructive parameters in connection with the internal state of aged micaceous insulation systems. After a short review of the conventional cumulative aging theory, it is pointed out that residual breakdown data do not always obey the theory, and that the internal change observed with SEM (scanning electron microscopy) seems to reflect on the measured values. To explain the phenomena comprehensively, the concept of 'defect distribution X' is introduced. Breakdown voltage and nondestructive parameters are shown to be derived from the distribution X. An example of a simulation is presented.<>
{"title":"A new approach to breakdown voltage and nondestructive parameters of micaceous insulation systems","authors":"K. Kimura, Y. Kaneda, K. Itoh","doi":"10.1109/ICPADM.1991.172180","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172180","url":null,"abstract":"A novel mathematical approach is proposed to calculate the breakdown voltage and nondestructive parameters in connection with the internal state of aged micaceous insulation systems. After a short review of the conventional cumulative aging theory, it is pointed out that residual breakdown data do not always obey the theory, and that the internal change observed with SEM (scanning electron microscopy) seems to reflect on the measured values. To explain the phenomena comprehensively, the concept of 'defect distribution X' is introduced. Breakdown voltage and nondestructive parameters are shown to be derived from the distribution X. An example of a simulation is presented.<<ETX>>","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"35 1","pages":"769-772 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86424174","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 : 1991-07-08DOI: 10.1109/ICPADM.1991.172057
R. Ross, J. Smit
Water trees as degradation products contain information about the aging process (es). The likelihood of oxidation, ion diffusion, and chain scission occurring during water tree growth in polyethylene insulation is discussed. The possible roles of the three processes are discussed. They cooperate in water tree growth, but may compete with respect to reaction products. It is also pointed out that antioxidants may play a dual role if they can be easily oxidized to ionic species. It is concluded that, with testing, care must be taken to accelerate the right process, because many parameters influence the growth rate of water trees.<>
{"title":"Water tree growth processes in XLPE","authors":"R. Ross, J. Smit","doi":"10.1109/ICPADM.1991.172057","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172057","url":null,"abstract":"Water trees as degradation products contain information about the aging process (es). The likelihood of oxidation, ion diffusion, and chain scission occurring during water tree growth in polyethylene insulation is discussed. The possible roles of the three processes are discussed. They cooperate in water tree growth, but may compete with respect to reaction products. It is also pointed out that antioxidants may play a dual role if they can be easily oxidized to ionic species. It is concluded that, with testing, care must be taken to accelerate the right process, because many parameters influence the growth rate of water trees.<<ETX>>","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"33 1","pages":"214-217 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89060711","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 : 1991-07-08DOI: 10.1109/ICPADM.1991.172252
S. Sato, A. Kojima, N. Iijima, M. Sone, H. Mitsui
A microchannel plate was used to measure emitted electrons under high field and ultraviolet irradiation of a cathode within the range of 10/sup -19/ A to 10/sup -15/ A in high vacuum (1.3*10/sup -5/ Pa). It is found that photoelectrons are mainly emitted from a flat part of the cathode surface. The number of the electrons is kept constant below the inception field strength of the field emission. The inception field strength of the field emission does not depend on photon energy. The effect of the photon energy on the electron emission from the minute projections did not appear.<>
采用微通道板测量阴极在高真空(1.3*10/sup -5/ Pa)高场和紫外照射范围(10/sup -19/ A ~ 10/sup -15/ A)下的发射电子。发现光电子主要从阴极表面的平坦部分发射。电子的数目在场发射的起始场强之下保持不变。场发射的起始场强与光子能量无关。光子能量对微小投影的电子发射的影响没有出现。
{"title":"Property of electron emission under irradiation of ultraviolet ray and applying field","authors":"S. Sato, A. Kojima, N. Iijima, M. Sone, H. Mitsui","doi":"10.1109/ICPADM.1991.172252","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172252","url":null,"abstract":"A microchannel plate was used to measure emitted electrons under high field and ultraviolet irradiation of a cathode within the range of 10/sup -19/ A to 10/sup -15/ A in high vacuum (1.3*10/sup -5/ Pa). It is found that photoelectrons are mainly emitted from a flat part of the cathode surface. The number of the electrons is kept constant below the inception field strength of the field emission. The inception field strength of the field emission does not depend on photon energy. The effect of the photon energy on the electron emission from the minute projections did not appear.<<ETX>>","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"44 1","pages":"1040-1043 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83728135","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 : 1991-07-08DOI: 10.1109/ICPADM.1991.172164
K. Udayakumar, M. Panneerselvam, K. Dharmalingam
The authors report on an experimental investigation undertaken to quantify the effect of high humidity on the performance of epoxy resin insulations. The data obtained from the investigations have been used to calculate a new index called the cumulative characteristic factor, which uniquely grades the material and insulation systems exposed to permanently elevated humidity conditions. To assess the long-term behavior, endurance tests were also conducted with a newly designed environment cycle representing tropical climatic conditions. Based on the accelerated test data, a system model has been developed for predicting the insulation life. To validate the laboratory aging tests, a 11 kV current transformer was installed in a highly humid region in Madras City, India. The place of installation was a switchgear plant for air conditioning purposes. From the experimental investigations and model developed it was concluded that in the presence of permanently elevated humidity conditions bisphenol epoxy resins are susceptible to severe surface degradation within 2 to 3 years of installation.<>
{"title":"Endurance estimation of epoxy resin systems under synergistic environment of high relative humidity and electrical stress","authors":"K. Udayakumar, M. Panneerselvam, K. Dharmalingam","doi":"10.1109/ICPADM.1991.172164","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172164","url":null,"abstract":"The authors report on an experimental investigation undertaken to quantify the effect of high humidity on the performance of epoxy resin insulations. The data obtained from the investigations have been used to calculate a new index called the cumulative characteristic factor, which uniquely grades the material and insulation systems exposed to permanently elevated humidity conditions. To assess the long-term behavior, endurance tests were also conducted with a newly designed environment cycle representing tropical climatic conditions. Based on the accelerated test data, a system model has been developed for predicting the insulation life. To validate the laboratory aging tests, a 11 kV current transformer was installed in a highly humid region in Madras City, India. The place of installation was a switchgear plant for air conditioning purposes. From the experimental investigations and model developed it was concluded that in the presence of permanently elevated humidity conditions bisphenol epoxy resins are susceptible to severe surface degradation within 2 to 3 years of installation.<<ETX>>","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"18 1","pages":"711-714 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83791194","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 : 1991-07-08DOI: 10.1109/ICPADM.1991.172127
Y. Takahashi, T. Okamoto
The authors describe the main stream of academic insulating-materials research in Japan from the point of view of the history of the Symposium on Electric Insulating Materials. The symposium started in 1968 and has been held every autumn. The symposium was organized by several pioneer researchers of electrical insulating materials. The authors review the history of insulating materials research activities in Japan according to the number of scientific papers in the Symposium.<>
{"title":"Historical outlook of research activities through the Symposium on Electrical Insulating Materials","authors":"Y. Takahashi, T. Okamoto","doi":"10.1109/ICPADM.1991.172127","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172127","url":null,"abstract":"The authors describe the main stream of academic insulating-materials research in Japan from the point of view of the history of the Symposium on Electric Insulating Materials. The symposium started in 1968 and has been held every autumn. The symposium was organized by several pioneer researchers of electrical insulating materials. The authors review the history of insulating materials research activities in Japan according to the number of scientific papers in the Symposium.<<ETX>>","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"36 1","pages":"588-591 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90572245","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 : 1991-07-08DOI: 10.1109/ICPADM.1991.172288
I. Kitani, K. Kadowaki, K. Arii
Breakdown phenomena in a silicone-oil/polymer-film composite subjected to DC ramp voltage (0.5 kV/s) and a step voltage were studied with point-plane and plane-plane electrode systems. When the film was placed on the plane anode, the breakdown voltage of the composite with the ramp voltage was less than that for oil alone for both electrode systems as long as the film thickness was thin. Although the breakdown of the film due to charge deposition caused the complete breakdown of the composite for both systems, there was a difference in the transition process from the film breakdown to the complete breakdown. For both electrode systems, when the film was placed on the plane cathode, the increasing rate of the breakdown voltage with the increase in the film thickness was less than that for the film on the anode. In the point-plane system though the film breakdown was brought about by the charge deposition, it could not cause the complete breakdown. The breakdown of the composite was completed by the positive propagation from the point anode. In the plane-plane system, the magnitude of depositing positive charges on the film was too little to cause film breakdown under the ramp voltage. The complete breakdown was induced by the discharge in oil.<>
{"title":"DC voltage breakdown in silicone-oil/polymer-film composite","authors":"I. Kitani, K. Kadowaki, K. Arii","doi":"10.1109/ICPADM.1991.172288","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172288","url":null,"abstract":"Breakdown phenomena in a silicone-oil/polymer-film composite subjected to DC ramp voltage (0.5 kV/s) and a step voltage were studied with point-plane and plane-plane electrode systems. When the film was placed on the plane anode, the breakdown voltage of the composite with the ramp voltage was less than that for oil alone for both electrode systems as long as the film thickness was thin. Although the breakdown of the film due to charge deposition caused the complete breakdown of the composite for both systems, there was a difference in the transition process from the film breakdown to the complete breakdown. For both electrode systems, when the film was placed on the plane cathode, the increasing rate of the breakdown voltage with the increase in the film thickness was less than that for the film on the anode. In the point-plane system though the film breakdown was brought about by the charge deposition, it could not cause the complete breakdown. The breakdown of the composite was completed by the positive propagation from the point anode. In the plane-plane system, the magnitude of depositing positive charges on the film was too little to cause film breakdown under the ramp voltage. The complete breakdown was induced by the discharge in oil.<<ETX>>","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"89 1","pages":"1181-1184 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86666446","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 : 1991-07-08DOI: 10.1109/ICPADM.1991.172105
H. Muto, Y. Yamashita, Y. Maruyuma, Z. Iwata
The leakage current characteristic of degraded XLPE (cross-linked polyethylene) cable was investigated under DC and AC electric field. The cable with heavy vented tree degradation showed a typical increase of DC leakage current and Dc component. In this instance, the bridged vented tree plays an important role in the increase of this current. The low-frequency component of the charging current was observed in the type of cable. The DC leakage current, DC component, and low-frequency component of the charging current were found to vary in a complex manner, depending on the applied voltage and its history. This may be attributable to the change of the internal water tree structure.<>
{"title":"A study on leakage current characteristics of field aged XLPE cable","authors":"H. Muto, Y. Yamashita, Y. Maruyuma, Z. Iwata","doi":"10.1109/ICPADM.1991.172105","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172105","url":null,"abstract":"The leakage current characteristic of degraded XLPE (cross-linked polyethylene) cable was investigated under DC and AC electric field. The cable with heavy vented tree degradation showed a typical increase of DC leakage current and Dc component. In this instance, the bridged vented tree plays an important role in the increase of this current. The low-frequency component of the charging current was observed in the type of cable. The DC leakage current, DC component, and low-frequency component of the charging current were found to vary in a complex manner, depending on the applied voltage and its history. This may be attributable to the change of the internal water tree structure.<<ETX>>","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"2 1","pages":"494-497 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83635119","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 : 1991-07-08DOI: 10.1109/ICPADM.1991.172150
M. Akinaga, H. Fukuda, T. Fukami
PbTiO/sub 3/ thin films with preferred c-axis orientation were prepared on single crystal MgO
在MgO单晶上制备了具有优先c轴取向的PbTiO/ sub3 /薄膜
{"title":"Fabrication of c-axis oriented PbTiO/sub 3/ transducer films for SAW in high-T/sub c/ superconducting films","authors":"M. Akinaga, H. Fukuda, T. Fukami","doi":"10.1109/ICPADM.1991.172150","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172150","url":null,"abstract":"PbTiO/sub 3/ thin films with preferred c-axis orientation were prepared on single crystal MgO","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"94 1","pages":"659-661 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91123997","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 : 1991-07-08DOI: 10.1109/ICPADM.1991.172169
P.R. Krishnarmoorthy, S. Vijayakumari, K. Krishnaswamy, P. Thomas
Comparative experimental data on the effectiveness of benzotriazole (BTA) and 2,6 ditertiary butyl para cresol (DBPC) in inhibiting the accelerated oxidation of new as well as reclaimed transformer oils were obtained using the bomb oxidation apparatus. Benzotriazole is found to be more effective than DBPC in much lower concentrations. The energy of activation involved in the accelerated oxidation of uninhibited and inhibited oils deduced from the analysis of data is reported. Estimated lives of oils at the operating temperatures of the transformer are also reported. An addition of BTA to the extent of 1/10 to 1/15 the concentration of DBPC gives about the same improvement in the life of new oil as that of new oil inhibited with DBPC. Similar results are obtained in the case of reclaimed oil.<>
{"title":"Effect of benzotriazole and 2,6 ditertiary butyl para cresol on the accelerated oxidation of new and reclaimed transformer oils-a comparative study","authors":"P.R. Krishnarmoorthy, S. Vijayakumari, K. Krishnaswamy, P. Thomas","doi":"10.1109/ICPADM.1991.172169","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172169","url":null,"abstract":"Comparative experimental data on the effectiveness of benzotriazole (BTA) and 2,6 ditertiary butyl para cresol (DBPC) in inhibiting the accelerated oxidation of new as well as reclaimed transformer oils were obtained using the bomb oxidation apparatus. Benzotriazole is found to be more effective than DBPC in much lower concentrations. The energy of activation involved in the accelerated oxidation of uninhibited and inhibited oils deduced from the analysis of data is reported. Estimated lives of oils at the operating temperatures of the transformer are also reported. An addition of BTA to the extent of 1/10 to 1/15 the concentration of DBPC gives about the same improvement in the life of new oil as that of new oil inhibited with DBPC. Similar results are obtained in the case of reclaimed oil.<<ETX>>","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"1 1","pages":"732-735 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89639998","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 : 1991-07-08DOI: 10.1109/ICPADM.1991.172287
S. Pélissou, B. Noirhomme, J. Parpal
Preliminary results on the final breakdown mechanism of XLPE (cross-linked polyethylene) insulated field-aged cables are presented. The main goal is to determine the conditions that lead to the growth of electrical trees from water trees. Samples peeled off from two 28 kV and well-characterized (density, impurity and water content, field-water-tree density, oxidation) cables are considered. Aging conditions were 10 kV/mm, 60 Hz, 0.05 M NaCl solution, and 22-23 degrees C. The results indicate that after 8000 h of aging the lab-water-tree length reaches 65-70% of the sample thickness and is not much affected by the presence of field water trees. The influence of the physico-chemical properties and AC breakdown strength is also reported.<>
{"title":"Final breakdown mechanism","authors":"S. Pélissou, B. Noirhomme, J. Parpal","doi":"10.1109/ICPADM.1991.172287","DOIUrl":"https://doi.org/10.1109/ICPADM.1991.172287","url":null,"abstract":"Preliminary results on the final breakdown mechanism of XLPE (cross-linked polyethylene) insulated field-aged cables are presented. The main goal is to determine the conditions that lead to the growth of electrical trees from water trees. Samples peeled off from two 28 kV and well-characterized (density, impurity and water content, field-water-tree density, oxidation) cables are considered. Aging conditions were 10 kV/mm, 60 Hz, 0.05 M NaCl solution, and 22-23 degrees C. The results indicate that after 8000 h of aging the lab-water-tree length reaches 65-70% of the sample thickness and is not much affected by the presence of field water trees. The influence of the physico-chemical properties and AC breakdown strength is also reported.<<ETX>>","PeriodicalId":6450,"journal":{"name":"[1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials","volume":"40 1","pages":"1177-1180 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90364432","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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