Pub Date : 1990-09-10DOI: 10.1109/ICDL.1990.202920
K. Arii, M. Fujii, I. Kitani
A point electrode of a 0.1-mm-diam. tungsten wire was enclosed by a of about approximately 1-mm diam. gas bubble. After a voltage pulse application the bubble was deformed and then pushed to the plane electrode in the tested liquid. At the negative point, the bubble surface was rather smooth, although its shape was far from a sphere. Regular current and photocurrent pulses were observed when the bubble was attached to the point cathode. After the departure of the bubble from the point, the period of the pulses became long and random. When the bubble came close to the plane, light was emitted between the bubble and plane just before breakdown. At the positive point, a treelike surface was observed at the plane side of the bubble. Current and photocurrent pulses were not regular. When the tip of the treelike bubble went down to a point some distance from the plane, breakdown occurred. He, O/sub 2/, and SF6 affected the breakdown voltage of the bubble liquid composite for both polarities. Shortening the width of applied voltage pulse increased the breakdown voltage.<>
{"title":"Breakdown of gas liquid composite in divergent fields","authors":"K. Arii, M. Fujii, I. Kitani","doi":"10.1109/ICDL.1990.202920","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202920","url":null,"abstract":"A point electrode of a 0.1-mm-diam. tungsten wire was enclosed by a of about approximately 1-mm diam. gas bubble. After a voltage pulse application the bubble was deformed and then pushed to the plane electrode in the tested liquid. At the negative point, the bubble surface was rather smooth, although its shape was far from a sphere. Regular current and photocurrent pulses were observed when the bubble was attached to the point cathode. After the departure of the bubble from the point, the period of the pulses became long and random. When the bubble came close to the plane, light was emitted between the bubble and plane just before breakdown. At the positive point, a treelike surface was observed at the plane side of the bubble. Current and photocurrent pulses were not regular. When the tip of the treelike bubble went down to a point some distance from the plane, breakdown occurred. He, O/sub 2/, and SF6 affected the breakdown voltage of the bubble liquid composite for both polarities. Shortening the width of applied voltage pulse increased the breakdown voltage.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123719847","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 : 1990-09-10DOI: 10.1109/ICDL.1990.202935
O. Lesaint, P. Gournay, R. Tobazéon
A study of transient currents associated with the propagation of filamentary positive streamers in liquids is presented. Experimental measurements of currents in various liquids are analyzed with a model where the channel is simulated by a cylindrical conducting filament. This model is derived from those used to describe leader channels in gases. Good agreement is found between theory and experiments, indicating that the conductive channels behave more like leaders in gases than like streamers.<>
{"title":"Investigations on transient currents associated with streamer propagation in dielectric liquids","authors":"O. Lesaint, P. Gournay, R. Tobazéon","doi":"10.1109/ICDL.1990.202935","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202935","url":null,"abstract":"A study of transient currents associated with the propagation of filamentary positive streamers in liquids is presented. Experimental measurements of currents in various liquids are analyzed with a model where the channel is simulated by a cylindrical conducting filament. This model is derived from those used to describe leader channels in gases. Good agreement is found between theory and experiments, indicating that the conductive channels behave more like leaders in gases than like streamers.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122795870","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 : 1990-09-10DOI: 10.1109/ICDL.1990.202896
G. Touchard, P. Grimaud, T. Bottineau, S. Watanabe, J. Borzeix
An experiment on streaming potentials and electroosmosis is presented. In the streaming-potential experiment, the convected space charge density was determined along with the space charge density on the wall and the mean space charge density rho /sub m/. The value of rho /sub m/ determined from electroosmosis experiments was nearly the same. It was also shown that, in some cases, an applied electric field can generate a nonnegligible flow of petroleum through a microporous medium.<>
{"title":"Correlations between experiments on streaming potential and electroosmosis","authors":"G. Touchard, P. Grimaud, T. Bottineau, S. Watanabe, J. Borzeix","doi":"10.1109/ICDL.1990.202896","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202896","url":null,"abstract":"An experiment on streaming potentials and electroosmosis is presented. In the streaming-potential experiment, the convected space charge density was determined along with the space charge density on the wall and the mean space charge density rho /sub m/. The value of rho /sub m/ determined from electroosmosis experiments was nearly the same. It was also shown that, in some cases, an applied electric field can generate a nonnegligible flow of petroleum through a microporous medium.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":" 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132123670","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 : 1990-09-10DOI: 10.1109/ICDL.1990.202889
A. Ebe, M. Sone, H. Mitsui, K. Takaoka
The state of water in insulating oils was studied using infrared ray spectroscopy. It was found that there are many kinds of water clusters in the materials: monomer (H/sub 2/O), dimer(H/sub 2/O)/sub 2/, trimer(H/sub 2/O)/sub 3/, and polymer(H/sub 2/O)n. Under electrical stress, the states of water were changed by applying different electrical fields. The dimer state had no effect on the conduction, whereas trimer contributed to the conduction when the water content was higher.<>
{"title":"Effect of dissolved water on electrical conduction in dielectric liquid","authors":"A. Ebe, M. Sone, H. Mitsui, K. Takaoka","doi":"10.1109/ICDL.1990.202889","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202889","url":null,"abstract":"The state of water in insulating oils was studied using infrared ray spectroscopy. It was found that there are many kinds of water clusters in the materials: monomer (H/sub 2/O), dimer(H/sub 2/O)/sub 2/, trimer(H/sub 2/O)/sub 3/, and polymer(H/sub 2/O)n. Under electrical stress, the states of water were changed by applying different electrical fields. The dimer state had no effect on the conduction, whereas trimer contributed to the conduction when the water content was higher.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"321 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131779411","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 : 1990-09-10DOI: 10.1109/ICDL.1990.202882
W. Dittrich, H. Hill, E. Kinzel
The voltage/current characteristic in propylene carbonate shows an exponential rise of current above 100 kV/cm, due to charge injection at the electrode/liquid interface. Possible means to abate this injection were investigated, and experimental results are presented. Abatement of injection currents is an essential condition for the use of high-permittivity liquids (e.g., propylene carbonate) as fluid dielectrics in electrostatic machines. A large number of experimental series have been performed which show the possibility of field-induced passivation.<>
{"title":"Abatement of injection currents in propylene carbonate","authors":"W. Dittrich, H. Hill, E. Kinzel","doi":"10.1109/ICDL.1990.202882","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202882","url":null,"abstract":"The voltage/current characteristic in propylene carbonate shows an exponential rise of current above 100 kV/cm, due to charge injection at the electrode/liquid interface. Possible means to abate this injection were investigated, and experimental results are presented. Abatement of injection currents is an essential condition for the use of high-permittivity liquids (e.g., propylene carbonate) as fluid dielectrics in electrostatic machines. A large number of experimental series have been performed which show the possibility of field-induced passivation.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132037498","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 : 1990-09-10DOI: 10.1109/ICDL.1990.202911
R. Hanaoka, R. Ishibashi, T. Aoyagi, Y. Asada, T. Nishi
Conduction current and liquid motion under divergent electric fields in transformer oil were measured, and the effect of polarity on the DC breakdown voltage was clarified. Electric field and space charge density distributions near the breakdown were computed, taking the liquid motion into account. It was deduced that the breakdown occurred due to the field enhancement in front of the plane electrode, and it was demonstrated that the breakdown voltage in the case of the negative sharp electrode was much higher than in the case of the positive one.<>
{"title":"Effect of liquid motion on breakdown voltage under divergent electric fields in transformer oil","authors":"R. Hanaoka, R. Ishibashi, T. Aoyagi, Y. Asada, T. Nishi","doi":"10.1109/ICDL.1990.202911","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202911","url":null,"abstract":"Conduction current and liquid motion under divergent electric fields in transformer oil were measured, and the effect of polarity on the DC breakdown voltage was clarified. Electric field and space charge density distributions near the breakdown were computed, taking the liquid motion into account. It was deduced that the breakdown occurred due to the field enhancement in front of the plane electrode, and it was demonstrated that the breakdown voltage in the case of the negative sharp electrode was much higher than in the case of the positive one.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123140582","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 : 1990-09-10DOI: 10.1109/ICDL.1990.202955
C. Lamarre, M. Duval, J. Crine
The advantages of using metal deactivators or passivators in mineral transformer oils are briefly reviewed. The evidence (from laboratory tests and in service) has demonstrated that they considerably prolong the thermal active life of oils. Metal deactivators can also reduce the static electrification of transformers oils. In addition to increasing the thermal resistance of the oil, they also keep its electrical properties unaltered for a longer period of time and reduce its charging tendency. Although questions have been raised regarding the nature and concentration of metal deactivators as well as their interactions with other additives, none of these questions should impede the use of metal deactivators in transformer oil.<>
{"title":"On the influence of metal deactivators on some properties of transformer oils","authors":"C. Lamarre, M. Duval, J. Crine","doi":"10.1109/ICDL.1990.202955","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202955","url":null,"abstract":"The advantages of using metal deactivators or passivators in mineral transformer oils are briefly reviewed. The evidence (from laboratory tests and in service) has demonstrated that they considerably prolong the thermal active life of oils. Metal deactivators can also reduce the static electrification of transformers oils. In addition to increasing the thermal resistance of the oil, they also keep its electrical properties unaltered for a longer period of time and reduce its charging tendency. Although questions have been raised regarding the nature and concentration of metal deactivators as well as their interactions with other additives, none of these questions should impede the use of metal deactivators in transformer oil.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"224 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133819139","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 : 1990-09-10DOI: 10.1109/ICDL.1990.202951
H. Borsi, U. Schroder
The authors report the results of fundamental investigations on the behavior of partial discharges (PDs) in insulating fluids. The shape of PD pulses is recorded with a special measuring system and the characteristics of PD pulses and their dependencies in insulating liquids are determined. Some of the most important parameters investigated are the dependencies of the PD pulses on the electrode configuration, the magnitude of the test voltage, and the conditions of the oil. The relationship between the apparent charge, the PD energy, and the test voltage is determined.<>
{"title":"Fundamental investigations concerning the behaviour of partial discharges (PD) in dielectric liquids","authors":"H. Borsi, U. Schroder","doi":"10.1109/ICDL.1990.202951","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202951","url":null,"abstract":"The authors report the results of fundamental investigations on the behavior of partial discharges (PDs) in insulating fluids. The shape of PD pulses is recorded with a special measuring system and the characteristics of PD pulses and their dependencies in insulating liquids are determined. Some of the most important parameters investigated are the dependencies of the PD pulses on the electrode configuration, the magnitude of the test voltage, and the conditions of the oil. The relationship between the apparent charge, the PD energy, and the test voltage is determined.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"4 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121007901","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 : 1990-09-10DOI: 10.1109/ICDL.1990.202969
K. Arii, M. Fujii, I. Kitani
Breakdown voltage of trans-decalin and cyclohexane was measured at various pressures. After degassing the liquid by freeze-pump thaw cycles, it was transferred in vacuum to the test cell containing the electrodes, and the cell was sealed with argon or ammonia gas at a certain pressure. In trans-decalin, the breakdown voltage ratio for argon as compared to that for ammonia was 1.2-1.3; that is, ammonia could reduce the breakdown voltage. At the tail of the voltage pulse, back discharge light was found in the liquid for the ammonia atmosphere. The spectrum of the light included emission peaks at 550 nm of the ammonia molecule, which means that ammonia ions produced by the pulse were located near the point tip and recombined with electrons injected from the tip. In cyclohexane, the breakdown voltage ratio was 1.05-1.1. Breakdown velocities estimated from time lag measurement at 1 mm gap were 50-120 m/s, depending on the applied voltage.<>
{"title":"Breakdown of t-decalin and cyclohexane in divergent fields","authors":"K. Arii, M. Fujii, I. Kitani","doi":"10.1109/ICDL.1990.202969","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202969","url":null,"abstract":"Breakdown voltage of trans-decalin and cyclohexane was measured at various pressures. After degassing the liquid by freeze-pump thaw cycles, it was transferred in vacuum to the test cell containing the electrodes, and the cell was sealed with argon or ammonia gas at a certain pressure. In trans-decalin, the breakdown voltage ratio for argon as compared to that for ammonia was 1.2-1.3; that is, ammonia could reduce the breakdown voltage. At the tail of the voltage pulse, back discharge light was found in the liquid for the ammonia atmosphere. The spectrum of the light included emission peaks at 550 nm of the ammonia molecule, which means that ammonia ions produced by the pulse were located near the point tip and recombined with electrons injected from the tip. In cyclohexane, the breakdown voltage ratio was 1.05-1.1. Breakdown velocities estimated from time lag measurement at 1 mm gap were 50-120 m/s, depending on the applied voltage.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123953941","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 : 1990-09-10DOI: 10.1109/ICDL.1990.202873
G. Bressi, M. Cambiaghi, G. Carugno, E. Conti, B. Dainese, G. Prete, N. Toniolo
A purification system for methane has been developed which made it possible to reach an electron attenuation length in liquid methane >1 m. With this purity level, one could carry out a systematic study of the electron mobility. A free-ion yield of cosmic rays and protons of 1>E>7 MeV was also measured. The results obtained confirm the feasibility of a liquid methane detector for fast neutrons.<>
{"title":"Liquid methane properties and possible use as fast neutron detector","authors":"G. Bressi, M. Cambiaghi, G. Carugno, E. Conti, B. Dainese, G. Prete, N. Toniolo","doi":"10.1109/ICDL.1990.202873","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202873","url":null,"abstract":"A purification system for methane has been developed which made it possible to reach an electron attenuation length in liquid methane >1 m. With this purity level, one could carry out a systematic study of the electron mobility. A free-ion yield of cosmic rays and protons of 1>E>7 MeV was also measured. The results obtained confirm the feasibility of a liquid methane detector for fast neutrons.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124863755","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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