Pub Date : 1990-09-10DOI: 10.1109/ICDL.1990.202917
M. Bologa, I. Kozhukhar, F. M. Sazhin, N.S. Alekseeva, O. I. Mardarsky, A. Maiboroda, O. V. Motorin
A general approach to solving the electroconvective heat exchange problem for homogeneous and heterogeneous vapor-liquid media is analyzed. The authors substitute mechanisms of charge formation associated with medium ionization and ion neutralization at the electrodes, availability of a double electric layer at the electrode-medium interfaces, or charge injection from one of the electrodes. Particular attention is given to the electrification and instability of heterogeneous vapor-liquid systems determined by the induction of charge at the interface in the external field due to various electrophysical parameters and related forces of the electrostatic pressure. Experimental data in this area are summarized.<>
{"title":"The role of electroconvective phenomena in heat exchange stepping up","authors":"M. Bologa, I. Kozhukhar, F. M. Sazhin, N.S. Alekseeva, O. I. Mardarsky, A. Maiboroda, O. V. Motorin","doi":"10.1109/ICDL.1990.202917","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202917","url":null,"abstract":"A general approach to solving the electroconvective heat exchange problem for homogeneous and heterogeneous vapor-liquid media is analyzed. The authors substitute mechanisms of charge formation associated with medium ionization and ion neutralization at the electrodes, availability of a double electric layer at the electrode-medium interfaces, or charge injection from one of the electrodes. Particular attention is given to the electrification and instability of heterogeneous vapor-liquid systems determined by the induction of charge at the interface in the external field due to various electrophysical parameters and related forces of the electrostatic pressure. Experimental data in this area are summarized.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"28 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":"115504695","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.1990.202953
A. Goldman, M. Goldman, R. S. Sigmond, T. Sigmond
Experimental results are presented on the direct interaction between corona and insulating surfaces, including the generation of water by corona oxidation of the polymer. Measurements of indirect corona-polymer interaction by corona exposure of distilled water with submerged polymer samples are also reported. It is shown that corona discharges in ambient air will form a water layer on any exposed polymer surface, both by bringing water to the surface made hydrophilic by the corona, and by producing water from the polymer itself, by oxidation. Water exposed to air corona becomes acid and oxidizing, and causes marked aging effects on polymer surfaces. Thus, any model of the action of air corona discharges on polymer surfaces must include the presence and effects of an intermediary aqueous electrolyte surface layer.<>
{"title":"On the role of water in the ageing of polymers in air-insulated electrical systems","authors":"A. Goldman, M. Goldman, R. S. Sigmond, T. Sigmond","doi":"10.1109/ICDL.1990.202953","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202953","url":null,"abstract":"Experimental results are presented on the direct interaction between corona and insulating surfaces, including the generation of water by corona oxidation of the polymer. Measurements of indirect corona-polymer interaction by corona exposure of distilled water with submerged polymer samples are also reported. It is shown that corona discharges in ambient air will form a water layer on any exposed polymer surface, both by bringing water to the surface made hydrophilic by the corona, and by producing water from the polymer itself, by oxidation. Water exposed to air corona becomes acid and oxidizing, and causes marked aging effects on polymer surfaces. Thus, any model of the action of air corona discharges on polymer surfaces must include the presence and effects of an intermediary aqueous electrolyte surface layer.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"50 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":"124151310","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.1990.202892
S. Watanabe, K. Tanabe, M. Fujii, A. Ohashi, A. Zerghouni, G. Touchard
Experiments were conducted to determine whether electrification is most effectively reduced by ionic or nonionic additive substances. The authors performed tests on the antielectrification effects of a variety of additives, and found that, for use with transformer oil, nonionic substances give more satisfactory results. In the present experiment, the relation between chemical structure and the electrification inhibiting effect was evaluated for 11 types of nonionic additives (of the polyethylene group) having known structures.<>
{"title":"The relation between the chemical structure of anti additives and streaming current","authors":"S. Watanabe, K. Tanabe, M. Fujii, A. Ohashi, A. Zerghouni, G. Touchard","doi":"10.1109/ICDL.1990.202892","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202892","url":null,"abstract":"Experiments were conducted to determine whether electrification is most effectively reduced by ionic or nonionic additive substances. The authors performed tests on the antielectrification effects of a variety of additives, and found that, for use with transformer oil, nonionic substances give more satisfactory results. In the present experiment, the relation between chemical structure and the electrification inhibiting effect was evaluated for 11 types of nonionic additives (of the polyethylene group) having known structures.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"34 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":"116319326","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.1990.202959
P. Mallet
In order to better understand the behavior of industrial liquids under high fields, a method has been developed for studying prebreakdown phenomena via measurements of partial discharges. The method (referred to as the step method) is an improvement on a method developed by a CIGRE Task Force TF 15-02-02 which involves measuring the partial discharge inception voltage (PDIV) in a very inhomogeneous field (needle to sphere gap). Preliminary tests showed that the CIGRE method does not characterize the size of the liquid. This defect is overcome with the proposed step method. Results on the effects of conditioning and aging obtained with the proposed technique are presented.<>
{"title":"Characterization of dielectric liquids by measurement of the partial discharge inception voltage","authors":"P. Mallet","doi":"10.1109/ICDL.1990.202959","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202959","url":null,"abstract":"In order to better understand the behavior of industrial liquids under high fields, a method has been developed for studying prebreakdown phenomena via measurements of partial discharges. The method (referred to as the step method) is an improvement on a method developed by a CIGRE Task Force TF 15-02-02 which involves measuring the partial discharge inception voltage (PDIV) in a very inhomogeneous field (needle to sphere gap). Preliminary tests showed that the CIGRE method does not characterize the size of the liquid. This defect is overcome with the proposed step method. Results on the effects of conditioning and aging obtained with the proposed technique are presented.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"33 6 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":"123485014","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.1990.202967
C. Frei
The transition between the fast and the slow components in the distribution of the time lags to breakdown has been investigated for several liquids whose coefficients of dynamic viscosity and permittivity differ by large amounts. Results of breakdown measurements for different hydrocarbon and chloro-hydrocarbon liquids are presented. The results are in agreement with the hypothesis that the transition occurs at the instant when the electrically stressed liquid layer becomes hydrodynamically unstable.<>
{"title":"Electrohydrodynamic motion and breakdown in liquids","authors":"C. Frei","doi":"10.1109/ICDL.1990.202967","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202967","url":null,"abstract":"The transition between the fast and the slow components in the distribution of the time lags to breakdown has been investigated for several liquids whose coefficients of dynamic viscosity and permittivity differ by large amounts. Results of breakdown measurements for different hydrocarbon and chloro-hydrocarbon liquids are presented. The results are in agreement with the hypothesis that the transition occurs at the instant when the electrically stressed liquid layer becomes hydrodynamically unstable.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"82 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":"125846759","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.1990.202898
R. Dempsey, T. Gallagher, B. Scaife
Calculations are presented for the electrostatic potential in and around a composite dielectric sphere, containing a noncentral spherical dielectric inclusion, subjected to an axial uniform external field. Some numerical results are presented and their significance is discussed. It is shown that the field at the center of the inclusion is only weakly dependent on the degree of eccentricity.<>
{"title":"Computation of the potential distribution for a composite dielectric sphere with a noncentral spherical inclusion polarized by a static uniform external field","authors":"R. Dempsey, T. Gallagher, B. Scaife","doi":"10.1109/ICDL.1990.202898","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202898","url":null,"abstract":"Calculations are presented for the electrostatic potential in and around a composite dielectric sphere, containing a noncentral spherical dielectric inclusion, subjected to an axial uniform external field. Some numerical results are presented and their significance is discussed. It is shown that the field at the center of the inclusion is only weakly dependent on the degree of eccentricity.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"57 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":"129577362","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.1990.202868
L. V. Lukin, B. Yakovlev
An experimental approach is developed to determine the range (distance traveled) of electrons with low ( approximately 1 eV) initial kinetic energy before solvation in hydrocarbon liquids. The distance may be associated with several processes, including electron thermalization, transport of quasi-free thermalized electrons, and electron transfer through shallow traps after primary localization. The thermalization length, l/sub th/ approximately=5.5 nm, is the same for methylcyclohexane (MCH) and squalene (Sq). The length, l/sub th/ >
{"title":"Ranges of presolvated electrons in nonpolar liquids","authors":"L. V. Lukin, B. Yakovlev","doi":"10.1109/ICDL.1990.202868","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202868","url":null,"abstract":"An experimental approach is developed to determine the range (distance traveled) of electrons with low ( approximately 1 eV) initial kinetic energy before solvation in hydrocarbon liquids. The distance may be associated with several processes, including electron thermalization, transport of quasi-free thermalized electrons, and electron transfer through shallow traps after primary localization. The thermalization length, l/sub th/ approximately=5.5 nm, is the same for methylcyclohexane (MCH) and squalene (Sq). The length, l/sub th/ <or approximately=1 nm, in liquid MCH is small compared with the de Broglie wavelength of the thermal electron. This means that the electron is unlikely to remain quasi-free at thermal energy in the liquid. In MCH fast solvation seems to occur just after primary electron trapping. The magnitude of l/sub th/ correlates with matrix viscosity eta .<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"9 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":"131033972","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.1990.202965
C. Mazzetti, M. Pompili, R. Cecere, E. Forster
Several synthetic dielectric fluids with significantly different molecular structures were investigated with regard to their conduction and breakdown behavior to determine the relation between these processes under DC and AC conditions. M&DBT, DTE, DINP, PXE, PFPE, and PPMS were the fluids studied. The results show a lack of correlation between the two processes. The presence of spectral structural features or of electronegative atoms such as fluorine appears to overshadow the influence of charge transport on electrical breakdown. The significance of these findings is discussed in the light of available information on the electronic and molecular structure of these fluids. Conductivity by itself is not a good indicator of the expected breakdown voltage levels. Although within a family of liquids such as aliphatic hydrocarbons higher conductivities lead to lower breakdown voltages, this relationship does not hold for fluids of different molecular structures.<>
{"title":"The effect of molecular structure of dielectric fluids on their conduction breakdown","authors":"C. Mazzetti, M. Pompili, R. Cecere, E. Forster","doi":"10.1109/ICDL.1990.202965","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202965","url":null,"abstract":"Several synthetic dielectric fluids with significantly different molecular structures were investigated with regard to their conduction and breakdown behavior to determine the relation between these processes under DC and AC conditions. M&DBT, DTE, DINP, PXE, PFPE, and PPMS were the fluids studied. The results show a lack of correlation between the two processes. The presence of spectral structural features or of electronegative atoms such as fluorine appears to overshadow the influence of charge transport on electrical breakdown. The significance of these findings is discussed in the light of available information on the electronic and molecular structure of these fluids. Conductivity by itself is not a good indicator of the expected breakdown voltage levels. Although within a family of liquids such as aliphatic hydrocarbons higher conductivities lead to lower breakdown voltages, this relationship does not hold for fluids of different molecular structures.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"14 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":"122372341","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.1990.202869
J. Casanovas, J.P. Guelfucci, O. Caselles
Excited states are detected in the VUV photoionization spectra of cyclohexane and dimethyl-2-2-butane. Some of the discernible peaks of cyclohexane can be assigned as belonging to the Rydberg series observed in the gas phase. The spectra structures of liquid (photoionization) and gaseous (absorption) D-2-2-B are also comparable. The ionization quantum yield and thermalization range parameter of D-2-2-B were determined up to 2 eV above the ionization threshold of liquid D-2-2-B. Comparison with the values of the same parameters when quenchers are present seems to indicate that quenchers interact more with the excited states than with epithermal electrons.<>
{"title":"Excited states and thermalization distances of photons created by VUV photoionization of pure liquid alkanes","authors":"J. Casanovas, J.P. Guelfucci, O. Caselles","doi":"10.1109/ICDL.1990.202869","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202869","url":null,"abstract":"Excited states are detected in the VUV photoionization spectra of cyclohexane and dimethyl-2-2-butane. Some of the discernible peaks of cyclohexane can be assigned as belonging to the Rydberg series observed in the gas phase. The spectra structures of liquid (photoionization) and gaseous (absorption) D-2-2-B are also comparable. The ionization quantum yield and thermalization range parameter of D-2-2-B were determined up to 2 eV above the ionization threshold of liquid D-2-2-B. Comparison with the values of the same parameters when quenchers are present seems to indicate that quenchers interact more with the excited states than with epithermal electrons.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"71 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":"131333585","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.1990.202948
H. House, N. Hosokawa
The development of an electrooptic probe system to measure stress and charge conditions near a barrier in an oil-insulated system working at 300-kV AC or 600-kV impulse is described. A cylindrical channel, filled with a high Kerr coefficient liquid, was used within the barrier. Cross polarizer/analyzer techniques were used to measure the stress and its direction. The system is nonperturbing and gives protection against interference. Since the method relies on the calculation of the barrier surface stress from the measured probe stress, the permittivity-deduced AC stresses are acceptable, but the calculation for the slowly-changing stresses is dependent on the variable and ill-defined resistivities. A closed probe purification system had to be used. The results of the stress measurements are consistent with the Kerr theory.<>
{"title":"Electro-optic measurement of electric stress in oil-barrier insulating systems","authors":"H. House, N. Hosokawa","doi":"10.1109/ICDL.1990.202948","DOIUrl":"https://doi.org/10.1109/ICDL.1990.202948","url":null,"abstract":"The development of an electrooptic probe system to measure stress and charge conditions near a barrier in an oil-insulated system working at 300-kV AC or 600-kV impulse is described. A cylindrical channel, filled with a high Kerr coefficient liquid, was used within the barrier. Cross polarizer/analyzer techniques were used to measure the stress and its direction. The system is nonperturbing and gives protection against interference. Since the method relies on the calculation of the barrier surface stress from the measured probe stress, the permittivity-deduced AC stresses are acceptable, but the calculation for the slowly-changing stresses is dependent on the variable and ill-defined resistivities. A closed probe purification system had to be used. The results of the stress measurements are consistent with the Kerr theory.<<ETX>>","PeriodicalId":193137,"journal":{"name":"10th International Conference on Conduction and Breakdown in Dielectric Liquids","volume":"6 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":"126369585","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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