Pub Date : 1975-11-01DOI: 10.1109/CEIDP.1975.7736669
J. Devins, S. Rzad
In many practical insulation systems, failure initiates at asperities or inclusions at which very high localized fields exist. It is the purpose of this work to examine a method for modifying the insulation so that field grading will occur and the buildup of excessive fields be prevented. In order to accomplish this field grading, we propose to take advantage of the field-dependence of the conductivity of weak electrolytes, the so-called second Wien effect.1 The phenomenon is well understood and documented2 and involves the increased dissociation of weak electrolytes into ions with increased electrical fields, producing a higher conductivity in the high field region and therefore a reduction in this field.
{"title":"Ionic conduction and field grading in dielectrics","authors":"J. Devins, S. Rzad","doi":"10.1109/CEIDP.1975.7736669","DOIUrl":"https://doi.org/10.1109/CEIDP.1975.7736669","url":null,"abstract":"In many practical insulation systems, failure initiates at asperities or inclusions at which very high localized fields exist. It is the purpose of this work to examine a method for modifying the insulation so that field grading will occur and the buildup of excessive fields be prevented. In order to accomplish this field grading, we propose to take advantage of the field-dependence of the conductivity of weak electrolytes, the so-called second Wien effect.1 The phenomenon is well understood and documented2 and involves the increased dissociation of weak electrolytes into ions with increased electrical fields, producing a higher conductivity in the high field region and therefore a reduction in this field.","PeriodicalId":121906,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1975","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134310790","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 : 1975-11-01DOI: 10.1109/CEIDP.1975.7736687
R. Anderson
The voltage at which an insulator in vacuum flashes over depends on the angle between the insulator-vacuum interface and the electric field.1,3 In the work reported here, fast high-voltage pulses (3 ns risetime) and nanosecond time resolution permit measurement of the time delay between voltage application and breakdown. Measurements indicate that much of the angular variation in breakdown voltage observed under fast-pulsed conditions is associated with a seconary electron emission avalanche1 5 at the insulator surface preceding breakdown. The voltage dependence of the time delay provides insight into the transition from electron avalanche to low-impedance discharge. Furthermore, there is evidence that a different mechanism may lead to surface flashover within a restricted range of electric field angles.
{"title":"Time-resolved measurements of surface flashover of conical insulators","authors":"R. Anderson","doi":"10.1109/CEIDP.1975.7736687","DOIUrl":"https://doi.org/10.1109/CEIDP.1975.7736687","url":null,"abstract":"The voltage at which an insulator in vacuum flashes over depends on the angle between the insulator-vacuum interface and the electric field.1,3 In the work reported here, fast high-voltage pulses (3 ns risetime) and nanosecond time resolution permit measurement of the time delay between voltage application and breakdown. Measurements indicate that much of the angular variation in breakdown voltage observed under fast-pulsed conditions is associated with a seconary electron emission avalanche1 5 at the insulator surface preceding breakdown. The voltage dependence of the time delay provides insight into the transition from electron avalanche to low-impedance discharge. Furthermore, there is evidence that a different mechanism may lead to surface flashover within a restricted range of electric field angles.","PeriodicalId":121906,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1975","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115631081","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 : 1975-11-01DOI: 10.1109/CEIDP.1975.7736684
M. Murata, Kōjirō Nakata, A. Yokoyama
It is generally considered that paper formation, if it is good, will have little effect on the dielectric breakdown strength of oil-impregnated Kraft paper for oF cable. However, little is known about defining good formation quantitatively.
{"title":"Quantitative estimation of paper formation and its effect on oil-impregnated paper","authors":"M. Murata, Kōjirō Nakata, A. Yokoyama","doi":"10.1109/CEIDP.1975.7736684","DOIUrl":"https://doi.org/10.1109/CEIDP.1975.7736684","url":null,"abstract":"It is generally considered that paper formation, if it is good, will have little effect on the dielectric breakdown strength of oil-impregnated Kraft paper for oF cable. However, little is known about defining good formation quantitatively.","PeriodicalId":121906,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1975","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123894422","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 : 1975-11-01DOI: 10.1109/CEIDP.1975.7736641
J. Proud, J. J. Auborn
The formation or presence of small bubbles from various sources plays an important role in the high field conduction and breakdown phenomena in hydrocarbon insulating liquids.1,2,3 The possibility of observing electron multiplication or Townsend α-processes is diminished by the presence of such bubbles which provide a competing gas phase in which electron avalanches develop relatively easily. Energetic electron processes may also be impeded by the presence of C-H bonds whose vibrational excitations provide a favorable energy loss mechanism for electrons.4 The eventual breaking of these bonds can also result in the evolution of hydrogen5 which can serve as one of the sources of gas bubbles.
{"title":"High field conduction and breakdown in aprotic liquids","authors":"J. Proud, J. J. Auborn","doi":"10.1109/CEIDP.1975.7736641","DOIUrl":"https://doi.org/10.1109/CEIDP.1975.7736641","url":null,"abstract":"The formation or presence of small bubbles from various sources plays an important role in the high field conduction and breakdown phenomena in hydrocarbon insulating liquids.1,2,3 The possibility of observing electron multiplication or Townsend α-processes is diminished by the presence of such bubbles which provide a competing gas phase in which electron avalanches develop relatively easily. Energetic electron processes may also be impeded by the presence of C-H bonds whose vibrational excitations provide a favorable energy loss mechanism for electrons.4 The eventual breaking of these bonds can also result in the evolution of hydrogen5 which can serve as one of the sources of gas bubbles.","PeriodicalId":121906,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1975","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117090601","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 : 1975-11-01DOI: 10.1109/CEIDP.1975.7736673
Harry Kreigh, Sart Sirisinha, W. Vaughan
Boule has described recently a method for characterizing the dielectric relaxation and complex formation in solutions of polar molecules in a nonpolar complexing solvent.1 This work reports complementary procedures which may be used when long live complexes are formed between two polar or one polar and one nonpolar molecules in solutions containing a large amount of noninteracting nonpolar solvent. Two experimental systems are analyzed in detail below.
{"title":"Dielectric methods for investigation of complex formation in liquids","authors":"Harry Kreigh, Sart Sirisinha, W. Vaughan","doi":"10.1109/CEIDP.1975.7736673","DOIUrl":"https://doi.org/10.1109/CEIDP.1975.7736673","url":null,"abstract":"Boule has described recently a method for characterizing the dielectric relaxation and complex formation in solutions of polar molecules in a nonpolar complexing solvent.1 This work reports complementary procedures which may be used when long live complexes are formed between two polar or one polar and one nonpolar molecules in solutions containing a large amount of noninteracting nonpolar solvent. Two experimental systems are analyzed in detail below.","PeriodicalId":121906,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1975","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115206471","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 : 1975-11-01DOI: 10.1109/CEIDP.1975.7736682
M. Mashikian, B. Whitney
If power cables insulated with compressed SF6 gas are to have widespread application, their installed cost must be substantially reduced from the present level. The 3-phase, as opposed to the single-phase, configuration has been viewed as a means for reducing cable cost since it allows the use of materials for the outer pipe which are less onerous to purchase and install.1,2 Another item affecting the cost of such a cable is the solid dielectric spacer required at frequent intervals to support the conductors. Post-type spacers, which are inherently less voluminous and easier to manufacture than the disc-type or cone-type spacer configurations commonly used in isolated-phase bus construction, offer the possibility of realizing appreciable economies, provided they are optimally designed. This paper reports on the development of a design method intended to minimize the volume of post-type spacers for 3-phase SF6 gas-insulated cables.
{"title":"Optimized post-type spacers for 3-phase SF6 insulated cables","authors":"M. Mashikian, B. Whitney","doi":"10.1109/CEIDP.1975.7736682","DOIUrl":"https://doi.org/10.1109/CEIDP.1975.7736682","url":null,"abstract":"If power cables insulated with compressed SF6 gas are to have widespread application, their installed cost must be substantially reduced from the present level. The 3-phase, as opposed to the single-phase, configuration has been viewed as a means for reducing cable cost since it allows the use of materials for the outer pipe which are less onerous to purchase and install.1,2 Another item affecting the cost of such a cable is the solid dielectric spacer required at frequent intervals to support the conductors. Post-type spacers, which are inherently less voluminous and easier to manufacture than the disc-type or cone-type spacer configurations commonly used in isolated-phase bus construction, offer the possibility of realizing appreciable economies, provided they are optimally designed. This paper reports on the development of a design method intended to minimize the volume of post-type spacers for 3-phase SF6 gas-insulated cables.","PeriodicalId":121906,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1975","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132473657","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 : 1975-11-01DOI: 10.1109/CEIDP.1975.7736668
M. Morita, M. Hanai, H. Shimanuki, F. Aida
Among the water tree phenomena occurring in polyethylene (PE) and crosslinked polyethylene (XLPE) insulation, a bow tie tree phenomenon occuring from micro voids (less than 10 μm) in polymer was the subject of our research. Bow tie tree inception mechanism and its behavior was examined by model simulation test using a miniature cable. The results of this experiment proved that the bow tie tree inception and propagation was related to the oxidation reaction in the polymer. Based on this fact, the water tree endurance of XLPE using various curing agents and additives was measured in a “sheet” model test. The test revealed that bow tie tree occurrence would be greatly affected by the oxidation stability of the polymer and the rigidity of molecular linkage of the polymer.
{"title":"Effect of bow tie tree on PE and XLPE insulation","authors":"M. Morita, M. Hanai, H. Shimanuki, F. Aida","doi":"10.1109/CEIDP.1975.7736668","DOIUrl":"https://doi.org/10.1109/CEIDP.1975.7736668","url":null,"abstract":"Among the water tree phenomena occurring in polyethylene (PE) and crosslinked polyethylene (XLPE) insulation, a bow tie tree phenomenon occuring from micro voids (less than 10 μm) in polymer was the subject of our research. Bow tie tree inception mechanism and its behavior was examined by model simulation test using a miniature cable. The results of this experiment proved that the bow tie tree inception and propagation was related to the oxidation reaction in the polymer. Based on this fact, the water tree endurance of XLPE using various curing agents and additives was measured in a “sheet” model test. The test revealed that bow tie tree occurrence would be greatly affected by the oxidation stability of the polymer and the rigidity of molecular linkage of the polymer.","PeriodicalId":121906,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1975","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132071549","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 : 1975-11-01DOI: 10.1109/CEIDP.1975.7736676
M. Zahn
When sufficiently high voltages are applied to electrical insulators, electrical breakdown occurs at some time after the voltage is applied. This time delay to breakdown coupled to time of flight measurements of charge carrier mobilities obtained from peaks in the current waveform, provides information on insulation and conduction characteristics of the dielectrics. In addition, the bulk electric field and space charge distributions can be measured using the Kerr electro-optic effect for those dielectrics which become birefringent when stressed by high voltages, such as water1 and nitrobenzene.2 A short circuit analysis applied during the post breakdown period.
{"title":"Transient drift dominated unipolar conduction between coaxial cylinders","authors":"M. Zahn","doi":"10.1109/CEIDP.1975.7736676","DOIUrl":"https://doi.org/10.1109/CEIDP.1975.7736676","url":null,"abstract":"When sufficiently high voltages are applied to electrical insulators, electrical breakdown occurs at some time after the voltage is applied. This time delay to breakdown coupled to time of flight measurements of charge carrier mobilities obtained from peaks in the current waveform, provides information on insulation and conduction characteristics of the dielectrics. In addition, the bulk electric field and space charge distributions can be measured using the Kerr electro-optic effect for those dielectrics which become birefringent when stressed by high voltages, such as water1 and nitrobenzene.2 A short circuit analysis applied during the post breakdown period.","PeriodicalId":121906,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1975","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1975-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131640870","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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