Pub Date : 1988-10-16DOI: 10.1109/CEIDP.1988.26343
P. Mckenny, E. Forster, E. Kelley, R. Hebner
The initiation of streamers in a liquid under the application of negative impulse voltages to a needle-sphere gap is investigated. A square pulse is applied so that the prebreakdown streamer will not grow to breakdown. With application of pressure, the initial streamer is observed to collapse and disappear while the voltage remains on the tip. When the voltage is chopped, a new streamer appears which resembles the structure of the anode streamers. Its branches do not strictly follow the previous branches of the cathode streamer which injected the charge in the liquid. Using a simple model, approximately 11 nC is estimated to be injected into the liquid producing a charge density of 49 mu C/cm/sup 3/.<>
{"title":"Effect of pressure on the development of prebreakdown streamers","authors":"P. Mckenny, E. Forster, E. Kelley, R. Hebner","doi":"10.1109/CEIDP.1988.26343","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26343","url":null,"abstract":"The initiation of streamers in a liquid under the application of negative impulse voltages to a needle-sphere gap is investigated. A square pulse is applied so that the prebreakdown streamer will not grow to breakdown. With application of pressure, the initial streamer is observed to collapse and disappear while the voltage remains on the tip. When the voltage is chopped, a new streamer appears which resembles the structure of the anode streamers. Its branches do not strictly follow the previous branches of the cathode streamer which injected the charge in the liquid. Using a simple model, approximately 11 nC is estimated to be injected into the liquid producing a charge density of 49 mu C/cm/sup 3/.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131413426","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 : 1988-10-16DOI: 10.1109/CEIDP.1988.26352
B. S. Manjunath, K. Dwarakanath, K.S. Arunachala Sastry, R. Maruti
The authors describe measurements of breakdown potentials (V/sub 50/) in air over the pressure range of 0.09 to 0.6 MPa (absolute) under lightning impulse (1.2/50 mu s) and switching surge (100/2500 mu s and 250/2500 mu s) voltages for both positive and negative polarities in uniform fields (d=4 to 50 mm), and in nonuniform fields (5-mm-dia hemispherically ended rod-plane geometry) for gap lengths of 30, 40 and 50 mm. It is shown that the breakdown strength of air exhibits a slight saturation at pressures above 0.6 MPa under both types of voltages and polarities. Under uniform fields the V/sub 50/ for the switching surge voltage is generally lower than the corresponding lightning impulse data. Under nonuniform fields it is observed that, for a given gap, the critical pressure effect is seen for certain risetimes only. The breakdown voltage at any given gap also varies with the risetime of the waveform and appears to reach a maximum for about 100 mu s.<>
{"title":"Uniform and non-uniform breakdown in compressed air under lightning and switching impulse voltages","authors":"B. S. Manjunath, K. Dwarakanath, K.S. Arunachala Sastry, R. Maruti","doi":"10.1109/CEIDP.1988.26352","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26352","url":null,"abstract":"The authors describe measurements of breakdown potentials (V/sub 50/) in air over the pressure range of 0.09 to 0.6 MPa (absolute) under lightning impulse (1.2/50 mu s) and switching surge (100/2500 mu s and 250/2500 mu s) voltages for both positive and negative polarities in uniform fields (d=4 to 50 mm), and in nonuniform fields (5-mm-dia hemispherically ended rod-plane geometry) for gap lengths of 30, 40 and 50 mm. It is shown that the breakdown strength of air exhibits a slight saturation at pressures above 0.6 MPa under both types of voltages and polarities. Under uniform fields the V/sub 50/ for the switching surge voltage is generally lower than the corresponding lightning impulse data. Under nonuniform fields it is observed that, for a given gap, the critical pressure effect is seen for certain risetimes only. The breakdown voltage at any given gap also varies with the risetime of the waveform and appears to reach a maximum for about 100 mu s.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132213975","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 : 1988-10-16DOI: 10.1109/CEIDP.1988.26324
Yingsuo Zhang
Round-robin testing was performed in several laboratories to test the validity of the thermogravimetric point slope (TPS) standard method for the rapid thermal endurance testing of insulating materials. The results demonstrate that the accuracy, repeatability, practicability, and rationality criteria for a rapid thermal aging test method are met to a satisfactory degree by the TPS method. Theoretical and application analysis is given.<>
{"title":"The advantages and the round robin test work of thermogravimetric point slope (TPS) method","authors":"Yingsuo Zhang","doi":"10.1109/CEIDP.1988.26324","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26324","url":null,"abstract":"Round-robin testing was performed in several laboratories to test the validity of the thermogravimetric point slope (TPS) standard method for the rapid thermal endurance testing of insulating materials. The results demonstrate that the accuracy, repeatability, practicability, and rationality criteria for a rapid thermal aging test method are met to a satisfactory degree by the TPS method. Theoretical and application analysis is given.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130912448","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 : 1988-10-16DOI: 10.1109/CEIDP.1988.26320
L. Fu, R. Fouracre, H. M. Banford
A regression experimental design was used to study gamma-irradiation damage to cured epoxy resin system. The three factors chosen as control variables were dose rate, dose period, and the ratio of hardener to resin. The percentage moisture absorption by weight and the glass transition temperature were used as indicators of material degradation. Only 15 sets of measurements were required to obtain the regression equation. The results showed that for this resin system the dose required to produce a given state of degradation is dependent on both dose rate and hardener concentration.<>
{"title":"An investigation of radiation damage in a cured epoxy resin system using regression experiment design","authors":"L. Fu, R. Fouracre, H. M. Banford","doi":"10.1109/CEIDP.1988.26320","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26320","url":null,"abstract":"A regression experimental design was used to study gamma-irradiation damage to cured epoxy resin system. The three factors chosen as control variables were dose rate, dose period, and the ratio of hardener to resin. The percentage moisture absorption by weight and the glass transition temperature were used as indicators of material degradation. Only 15 sets of measurements were required to obtain the regression equation. The results showed that for this resin system the dose required to produce a given state of degradation is dependent on both dose rate and hardener concentration.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134285271","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 : 1988-10-16DOI: 10.1109/CEIDP.1988.26309
Z. Kołaczkowski, A. Rybski, S. Grzybowski, E. Kuffel
The authors report results of an experimental study into the relationship between the prebreakdown current in nonuniform field gaps in vacuum under DC voltage and the transverse magnetic field. The gaps included point-point and point-plane arrangements and spacing from 1.0 to 5.0 mm. The critical magnetic field strengths causing the interruption of current flow in these gaps were calculated. It is shown that prebreakdown current in technical vacuum contains a nonemission component. It is also shown that the transverse magnetic field with density in the range B=0.02 T up to B=0.9 T always causes a reduction in prebreakdown current in vacuum for electrode arrangements investigated.<>
{"title":"Influence of transverse magnetic fields on prebreakdown current in non-uniform field gaps in vacuum","authors":"Z. Kołaczkowski, A. Rybski, S. Grzybowski, E. Kuffel","doi":"10.1109/CEIDP.1988.26309","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26309","url":null,"abstract":"The authors report results of an experimental study into the relationship between the prebreakdown current in nonuniform field gaps in vacuum under DC voltage and the transverse magnetic field. The gaps included point-point and point-plane arrangements and spacing from 1.0 to 5.0 mm. The critical magnetic field strengths causing the interruption of current flow in these gaps were calculated. It is shown that prebreakdown current in technical vacuum contains a nonemission component. It is also shown that the transverse magnetic field with density in the range B=0.02 T up to B=0.9 T always causes a reduction in prebreakdown current in vacuum for electrode arrangements investigated.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"32 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114114097","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 : 1988-10-16DOI: 10.1109/CEIDP.1988.26350
H. Anis, S. Ward
Particle charging under impulse voltage and particle position instability were investigated for coated gas-insulated system conductors. A contaminating particle is subject to position instability when the electrostatic force applied equals its weight. The effect of dielectric electrode coating under impulse voltages is insignificant when the resistivity of dielectric material is less than 10/sup 9/ Omega m. When the applied impulse voltage on the system is higher than the instability threshold, the particle's accumulated charge decreases drastically and the particle tends to lift off earlier, posing more danger to the system. When the applied impulse voltage on the system is higher than the instability threshold, the effect of the relative permittivity on the accumulated charge appears to be negligible while that of the coating resistivity seems to be insignificant.<>
{"title":"Performance of coated GIS conductors under impulse voltages","authors":"H. Anis, S. Ward","doi":"10.1109/CEIDP.1988.26350","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26350","url":null,"abstract":"Particle charging under impulse voltage and particle position instability were investigated for coated gas-insulated system conductors. A contaminating particle is subject to position instability when the electrostatic force applied equals its weight. The effect of dielectric electrode coating under impulse voltages is insignificant when the resistivity of dielectric material is less than 10/sup 9/ Omega m. When the applied impulse voltage on the system is higher than the instability threshold, the particle's accumulated charge decreases drastically and the particle tends to lift off earlier, posing more danger to the system. When the applied impulse voltage on the system is higher than the instability threshold, the effect of the relative permittivity on the accumulated charge appears to be negligible while that of the coating resistivity seems to be insignificant.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124322995","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 : 1988-10-16DOI: 10.1109/CEIDP.1988.26342
M. Watkins, P. Budenstein
Time-correlated specimen voltage, current, and light-intensity waveforms are related to tree initiation, onset of conduction, and tree propagation. Results on breakdown voltage and time of initiation relative to waveforms are also given. It is demonstrated that the breakdown phenomena in polymethylmethacrylate, as indicated by waveforms and self-luminosity, are similar to those described for breakdown in transformer oil.<>
{"title":"Time correlation of light intensity, voltage and current waveforms in breakdown of transformer oil under steep-fronted impulse excitation","authors":"M. Watkins, P. Budenstein","doi":"10.1109/CEIDP.1988.26342","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26342","url":null,"abstract":"Time-correlated specimen voltage, current, and light-intensity waveforms are related to tree initiation, onset of conduction, and tree propagation. Results on breakdown voltage and time of initiation relative to waveforms are also given. It is demonstrated that the breakdown phenomena in polymethylmethacrylate, as indicated by waveforms and self-luminosity, are similar to those described for breakdown in transformer oil.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125584296","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 : 1988-10-16DOI: 10.1109/CEIDP.1988.26341
P. F. Barber, T. S. Lauber
It is demonstrated that interelectrode capacitances can be obtained for three-dimensional electric-field geometries from the Z-matrix finite element formulation. The FORTRAN program WFEMZ has demonstrated that relatively large problems can be solved in reasonable time without overburdening available computer assets. It is shown that reusing suitable pass 1 results can save a substantial amount of computing time. Numerical accuracy of the method, though dependent upon the grid resolution selected by the user, is quite acceptable for reasonable grid spacings.<>
{"title":"Electrode capacitances from a Z-matrix finite element formulation","authors":"P. F. Barber, T. S. Lauber","doi":"10.1109/CEIDP.1988.26341","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26341","url":null,"abstract":"It is demonstrated that interelectrode capacitances can be obtained for three-dimensional electric-field geometries from the Z-matrix finite element formulation. The FORTRAN program WFEMZ has demonstrated that relatively large problems can be solved in reasonable time without overburdening available computer assets. It is shown that reusing suitable pass 1 results can save a substantial amount of computing time. Numerical accuracy of the method, though dependent upon the grid resolution selected by the user, is quite acceptable for reasonable grid spacings.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128585784","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 : 1988-10-16DOI: 10.1109/CEIDP.1988.26329
F. Campbell, A. K. Brewer, R. Orr, T. Janicke, A. Bruning
Experimental and theoretical work carried out on the hydrolytic deterioration of polyimide insulation on naval aircraft wiring is reviewed. Initial results are consistent with literature reports that mechanical strain (from bending and stretching the wires) has a strong influence on the hydrolysis reaction rate, and therefore the complex model for life prediction must include a multifactor modification of the Arrhenius Model. The critical technical issue is then one of developing the theoretical formula for determining the deterioration rate from the combination of fundamental kinetics and thermodynamic principles needed to express the multifactor stress effects on the commonly utilized Arrhenius formula.<>
{"title":"Hydrolytic deterioration of polyimide insulation on naval aircraft wiring","authors":"F. Campbell, A. K. Brewer, R. Orr, T. Janicke, A. Bruning","doi":"10.1109/CEIDP.1988.26329","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26329","url":null,"abstract":"Experimental and theoretical work carried out on the hydrolytic deterioration of polyimide insulation on naval aircraft wiring is reviewed. Initial results are consistent with literature reports that mechanical strain (from bending and stretching the wires) has a strong influence on the hydrolysis reaction rate, and therefore the complex model for life prediction must include a multifactor modification of the Arrhenius Model. The critical technical issue is then one of developing the theoretical formula for determining the deterioration rate from the combination of fundamental kinetics and thermodynamic principles needed to express the multifactor stress effects on the commonly utilized Arrhenius formula.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121900313","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 : 1988-08-20DOI: 10.1109/CEIDP.1988.26349
M. Ikeda, Y. Tanaka, K. Matsuo, T. Otsubo, Y. Ohki, N. Hozumi, M. Harashige
The possibility of developing a new insulating material with a high breakdown strength by copolymerizing styrene and ethylene has been reported previously (1986). In the present work, the authors report a study on the changes in morphology due to a different distribution of benzene rings and its effect on the electrical breakdown characteristics of these copolymers. It is concluded that styrene must be dispersed uniformly and bonded with ethylene in order to utilize fully the electron energy absorption of a benzene ring and raise the breakdown strength at a low styrene content.<>
{"title":"Influence of morphology on electrical breakdown characteristics of ethylene-styrene copolymers","authors":"M. Ikeda, Y. Tanaka, K. Matsuo, T. Otsubo, Y. Ohki, N. Hozumi, M. Harashige","doi":"10.1109/CEIDP.1988.26349","DOIUrl":"https://doi.org/10.1109/CEIDP.1988.26349","url":null,"abstract":"The possibility of developing a new insulating material with a high breakdown strength by copolymerizing styrene and ethylene has been reported previously (1986). In the present work, the authors report a study on the changes in morphology due to a different distribution of benzene rings and its effect on the electrical breakdown characteristics of these copolymers. It is concluded that styrene must be dispersed uniformly and bonded with ethylene in order to utilize fully the electron energy absorption of a benzene ring and raise the breakdown strength at a low styrene content.<<ETX>>","PeriodicalId":149735,"journal":{"name":"1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121835742","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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