Pub Date : 1989-10-29DOI: 10.1109/CEIDP.1989.69567
R. Coelho, L. Levy, D. Sarrail
The authors discuss 'local' models applicable to thin samples in which the injected charge density exceeds the intrinsic one. Experimental results are presented on such 'electrically inhomogeneous' samples. The experiment was performed on a Kapton sample in a space simulation chamber. The constant mobility hypothesis is valid provided that the initial field across the sample does not exceed some critical value. Comparison of the decay curves for bulk and surface charges permits an evaluation of the injection coefficient and its evolution. This in turn may help to improve the understanding of injection processes in dielectric materials, and to assess the effects of surface treatments.<>
{"title":"Transient voltage and injection in insulators","authors":"R. Coelho, L. Levy, D. Sarrail","doi":"10.1109/CEIDP.1989.69567","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69567","url":null,"abstract":"The authors discuss 'local' models applicable to thin samples in which the injected charge density exceeds the intrinsic one. Experimental results are presented on such 'electrically inhomogeneous' samples. The experiment was performed on a Kapton sample in a space simulation chamber. The constant mobility hypothesis is valid provided that the initial field across the sample does not exceed some critical value. Comparison of the decay curves for bulk and surface charges permits an evaluation of the injection coefficient and its evolution. This in turn may help to improve the understanding of injection processes in dielectric materials, and to assess the effects of surface treatments.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"5 1","pages":"327-331"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72732740","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69547
H. Ding, G. Sessler
Charge buildup in 30- mu m-thick films of polypropylene irradiated with monoenergetic electron beams of 10-45-keV energy is investigated. Using the split-Faraday cup, the mean charge depths at the beginning of electron injection, at the termination of injection, and 10 minutes after injection are measured. It is found that the depth increases with time during and after charging and depends on the 1.7th power of the electron energy. The depth increases also with the amount of injected charge. From the dynamics of charge motion during irradiation, the tradition-induced conductivity is determined a function of dose rate. It amounts to approximately 10/sup -14/ ( Omega .cm)/sup -1/ at 10/sup 4/ rad/s and is thus about an order of magnitude smaller than in Teflon.<>
{"title":"Charge buildup in polypropylene irradiated with monoenergetic electron beams","authors":"H. Ding, G. Sessler","doi":"10.1109/CEIDP.1989.69547","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69547","url":null,"abstract":"Charge buildup in 30- mu m-thick films of polypropylene irradiated with monoenergetic electron beams of 10-45-keV energy is investigated. Using the split-Faraday cup, the mean charge depths at the beginning of electron injection, at the termination of injection, and 10 minutes after injection are measured. It is found that the depth increases with time during and after charging and depends on the 1.7th power of the electron energy. The depth increases also with the amount of injected charge. From the dynamics of charge motion during irradiation, the tradition-induced conductivity is determined a function of dose rate. It amounts to approximately 10/sup -14/ ( Omega .cm)/sup -1/ at 10/sup 4/ rad/s and is thus about an order of magnitude smaller than in Teflon.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"1 1","pages":"204-209"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74592975","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69561
P. Kazimierski, M. Kryszewski, J. Tyczkowski
The electrical conductivity by electron hopping in the case of high electric fields is discussed with special attention to the Poole-Frenkel generation mechanism. Computer simulations of charge carriers tunneling between different kinds of localized states are presented. The model consequence is the existence of the exp(F/F/sub 0/) term in high-field direct current. These theoretical results are supported by measurements of current versus voltage characteristics for thin films of plasma polymers obtained by glow discharge in vapors of different organosilicon monomers. The present model also implies the existence of temperature-independent direct current in the case of sufficiently high electric fields.<>
{"title":"The high field conductivity in organosilicon plasma polymers","authors":"P. Kazimierski, M. Kryszewski, J. Tyczkowski","doi":"10.1109/CEIDP.1989.69561","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69561","url":null,"abstract":"The electrical conductivity by electron hopping in the case of high electric fields is discussed with special attention to the Poole-Frenkel generation mechanism. Computer simulations of charge carriers tunneling between different kinds of localized states are presented. The model consequence is the existence of the exp(F/F/sub 0/) term in high-field direct current. These theoretical results are supported by measurements of current versus voltage characteristics for thin films of plasma polymers obtained by glow discharge in vapors of different organosilicon monomers. The present model also implies the existence of temperature-independent direct current in the case of sufficiently high electric fields.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"38 1","pages":"290-295"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83238810","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69571
A. Ebe, N. Iijima, M. Sone, H. Mitsui
The state of water in liquid dielectric was analyzed by Fourier transform infrared spectroscopy during a conduction test. The liquid dielectric used was di-octyl-phthalate (DOP) with different proportions of water. The free water in DOP is shown to contribute to the conduction. The states of the free water or weakly bound water are shown to change under stress.<>
{"title":"Effect of dissolved water on electrical conduction in liquid dielectrics","authors":"A. Ebe, N. Iijima, M. Sone, H. Mitsui","doi":"10.1109/CEIDP.1989.69571","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69571","url":null,"abstract":"The state of water in liquid dielectric was analyzed by Fourier transform infrared spectroscopy during a conduction test. The liquid dielectric used was di-octyl-phthalate (DOP) with different proportions of water. The free water in DOP is shown to contribute to the conduction. The states of the free water or weakly bound water are shown to change under stress.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"44 1","pages":"352-357"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90880433","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69535
K. Kokari, N. Sugawara, Y. Kaneko, H. Tagashira
The electrical discharge characteristics of mixtures of helium and oxygen having a constant oxygen partial pressure were investigated to evaluate the safety of electric systems used in an undersea habitat. A comparison is made with the discharge characteristics of air. The spark breakdown voltage of the mixtures of helium and oxygen is at least 1.3 times higher than that of dry air throughout the pressure range studied (from 0.4 to 4.91 MPa). The minimum corona onset voltage was lower at pressures up to about 1.3 MPa than that of dry air. It was confirmed that at pressure higher than 1.3 MPa, it is possible to use even the usual electrical equipment in the mixture of helium and oxygen prevalent in an undersea habitat. It is noted that the spark breakdown voltage for the mixture of helium and oxygen has a plateau in the pressure range from 0.8 to 2 MPa.
{"title":"DC discharge phenomena in artificial air for an undersea habitat","authors":"K. Kokari, N. Sugawara, Y. Kaneko, H. Tagashira","doi":"10.1109/CEIDP.1989.69535","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69535","url":null,"abstract":"The electrical discharge characteristics of mixtures of helium and oxygen having a constant oxygen partial pressure were investigated to evaluate the safety of electric systems used in an undersea habitat. A comparison is made with the discharge characteristics of air. The spark breakdown voltage of the mixtures of helium and oxygen is at least 1.3 times higher than that of dry air throughout the pressure range studied (from 0.4 to 4.91 MPa). The minimum corona onset voltage was lower at pressures up to about 1.3 MPa than that of dry air. It was confirmed that at pressure higher than 1.3 MPa, it is possible to use even the usual electrical equipment in the mixture of helium and oxygen prevalent in an undersea habitat. It is noted that the spark breakdown voltage for the mixture of helium and oxygen has a plateau in the pressure range from 0.8 to 2 MPa.","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"1 1","pages":"131-136"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89102987","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69533
G. Letha, A. Venkatasami, T. Govindan
Experimental investigations conducted on a large number of experimental model samples made with polypropylene film and impregnated with SF/sub 6/ are reported. Samples and experiments were designed to identify and highlight the effects of critical factors, such as electrode material and configuration, winding tension, gas filling pressure, and impregnation cycle, on the partial-discharge behavior of the samples. It is noted that the results could serve as useful design data for the design of SF/sub 6/-filled high-voltage equipment using polypropylene film in particular and any plastic film in general.<>
{"title":"Partial discharge characteristics of gas impregnated polymeric insulation systems","authors":"G. Letha, A. Venkatasami, T. Govindan","doi":"10.1109/CEIDP.1989.69533","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69533","url":null,"abstract":"Experimental investigations conducted on a large number of experimental model samples made with polypropylene film and impregnated with SF/sub 6/ are reported. Samples and experiments were designed to identify and highlight the effects of critical factors, such as electrode material and configuration, winding tension, gas filling pressure, and impregnation cycle, on the partial-discharge behavior of the samples. It is noted that the results could serve as useful design data for the design of SF/sub 6/-filled high-voltage equipment using polypropylene film in particular and any plastic film in general.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"58 3 1","pages":"117-124"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83695711","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69546
R. Fouracre, H. M. Banford, D. Tedford, W. Huiming, X. Cao
Changes in the electrical properties of insulators exposed to high levels of ionizing radiation can have a significant effect on the lifetime of equipment incorporating such material. In order to obtain a knowledge of the processes involved, a series of experiments were undertaken on the effects of gamma irradiation, at dose levels up to a few megagrays (MGy), on the DC conductivity and the thermally stimulated discharge current (TSDC) spectra of two epoxy resin samples and a polyimide. Among other findings it is shown that the curves for DC conductivity can be used to measure the glass transition temperature T/sub G/. Initial differential scanning calorimetry measurements had shown that the T/sub G/ of the as-produced resin was 189 degrees C. Irradiation to 1 MGy reduced this value to 90 degrees C, and this was little changed by annealing. The activation energy below T/sub G/ decreased as a sequence of irradiation, but increased after annealing of the sample. Comparison with the TSDC spectra shows that the T/sub G/ of the system is lowered by the irradiation process, and it has also been shown that annealing increases the T/sub G/, although at this dose level it does not return to its original value. Measurements on polyimide indicate that there is a change in conduction mechanism after irradiation.<>
{"title":"Gamma irradiation effects in two epoxy resins and a polyimide","authors":"R. Fouracre, H. M. Banford, D. Tedford, W. Huiming, X. Cao","doi":"10.1109/CEIDP.1989.69546","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69546","url":null,"abstract":"Changes in the electrical properties of insulators exposed to high levels of ionizing radiation can have a significant effect on the lifetime of equipment incorporating such material. In order to obtain a knowledge of the processes involved, a series of experiments were undertaken on the effects of gamma irradiation, at dose levels up to a few megagrays (MGy), on the DC conductivity and the thermally stimulated discharge current (TSDC) spectra of two epoxy resin samples and a polyimide. Among other findings it is shown that the curves for DC conductivity can be used to measure the glass transition temperature T/sub G/. Initial differential scanning calorimetry measurements had shown that the T/sub G/ of the as-produced resin was 189 degrees C. Irradiation to 1 MGy reduced this value to 90 degrees C, and this was little changed by annealing. The activation energy below T/sub G/ decreased as a sequence of irradiation, but increased after annealing of the sample. Comparison with the TSDC spectra shows that the T/sub G/ of the system is lowered by the irradiation process, and it has also been shown that annealing increases the T/sub G/, although at this dose level it does not return to its original value. Measurements on polyimide indicate that there is a change in conduction mechanism after irradiation.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"6 1","pages":"198-203"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85481030","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69543
Z. Yingsuo, Bai Yi
The authors show by analysis and examples that the rapid thermal endurance testing methods of insulating materials are all approximate and simulations, in spite of the fact that some seem to have a strictly mathematical derivation or theoretical demonstration. It is suggested that the merits of the rapid methods should be evaluated by comparing test results with conventional aging.<>
{"title":"Theoretical analysis for rapid thermal endurance methods of insulating materials","authors":"Z. Yingsuo, Bai Yi","doi":"10.1109/CEIDP.1989.69543","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69543","url":null,"abstract":"The authors show by analysis and examples that the rapid thermal endurance testing methods of insulating materials are all approximate and simulations, in spite of the fact that some seem to have a strictly mathematical derivation or theoretical demonstration. It is suggested that the merits of the rapid methods should be evaluated by comparing test results with conventional aging.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"15 1","pages":"180-185"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82612211","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69572
M. Duval, F. Langdeau, P. Gervais, G. Bélanger
The influence of cellulose on acceptable gas-in-oil levels in high-voltage transformers as indicated by the value of the CO/sub 2//CO ratio is assessed by means of dissolved-gas analysis. The results presented here are based on 6932 gas-in-oil analyses on 1320 Hydro-Quebec transformers over a period of 20 years. Preliminary results indicate that C/sub 2/H/sub 4/ levels are affected by cellulose participation for both arcing and hot spots. The effect can be felt starting from CO/sub 2//CO ratios <6 for arcing and <2 for hot spots. These results suggest that the acceptable and dangerous levels of dissolved C/sub 2/H/sub 4/ in power transformers must be greatly reduced as the CO/sub 2//CO ratio in the oil decreases.<>
{"title":"Influence of paper insulation on acceptable gas-in-oil levels in transformers","authors":"M. Duval, F. Langdeau, P. Gervais, G. Bélanger","doi":"10.1109/CEIDP.1989.69572","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69572","url":null,"abstract":"The influence of cellulose on acceptable gas-in-oil levels in high-voltage transformers as indicated by the value of the CO/sub 2//CO ratio is assessed by means of dissolved-gas analysis. The results presented here are based on 6932 gas-in-oil analyses on 1320 Hydro-Quebec transformers over a period of 20 years. Preliminary results indicate that C/sub 2/H/sub 4/ levels are affected by cellulose participation for both arcing and hot spots. The effect can be felt starting from CO/sub 2//CO ratios <6 for arcing and <2 for hot spots. These results suggest that the acceptable and dangerous levels of dissolved C/sub 2/H/sub 4/ in power transformers must be greatly reduced as the CO/sub 2//CO ratio in the oil decreases.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"27 1","pages":"358-362"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86841632","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69570
S. Ochiai, H. Iwasaki, T. Mizutani, M. Ieda
Oil-polymer interactions were investigated using various combinations of polymer and oil. The current magnitudes in oil-polymer systems were in the following order: LDPE>HDPE>PP>PET>>FEP. These results are discussed, considering the solubility parameter (SP), the crystallinity of the polymer, and impurities in the polymer. It was found that the magnitude of the charging current in oil-polymer systems cannot be explained by the SP value alone. It is affected by impurities in the polymer (including antioxidant) close to the oil-polymer interface. Antioxidant is extracted from the polymer during sulfuric acid treatment. The treatment of sulfuric acid reduces the current and changes the TSC (thermally stimulated current) spectrum.<>
{"title":"Electrical conduction phenomena of oil/polymer systems","authors":"S. Ochiai, H. Iwasaki, T. Mizutani, M. Ieda","doi":"10.1109/CEIDP.1989.69570","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69570","url":null,"abstract":"Oil-polymer interactions were investigated using various combinations of polymer and oil. The current magnitudes in oil-polymer systems were in the following order: LDPE>HDPE>PP>PET>>FEP. These results are discussed, considering the solubility parameter (SP), the crystallinity of the polymer, and impurities in the polymer. It was found that the magnitude of the charging current in oil-polymer systems cannot be explained by the SP value alone. It is affected by impurities in the polymer (including antioxidant) close to the oil-polymer interface. Antioxidant is extracted from the polymer during sulfuric acid treatment. The treatment of sulfuric acid reduces the current and changes the TSC (thermally stimulated current) spectrum.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"17 1","pages":"346-351"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78767508","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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