Pub Date : 1989-10-29DOI: 10.1109/CEIDP.1989.69589
A. Hammoud, I. Myers
Four candidate materials were evaluated for use as high-temperature capacitor dielectrics. The materials investigated were polybenzimidazole polymer and three aramid papers. The samples were characterized with and without heat treatment in terms of their dielectric constant and loss. These properties of the heat-treated samples were also evaluated in a temperature range of 20 to 250 degrees C in the presence of electrical stress of 60 Hz, 50 V/mil. The AC and DC breakdown strengths of both dry and impregnated samples were determined at ambient conditions. The preliminary data indicate that heat treatment of the materials tested improves their dielectric properties and breakdown voltages. The AC and DC dielectric strengths are further improved upon impregnation with a suitable liquid.<>
{"title":"Evaluation of high temperature capacitor dielectrics","authors":"A. Hammoud, I. Myers","doi":"10.1109/CEIDP.1989.69589","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69589","url":null,"abstract":"Four candidate materials were evaluated for use as high-temperature capacitor dielectrics. The materials investigated were polybenzimidazole polymer and three aramid papers. The samples were characterized with and without heat treatment in terms of their dielectric constant and loss. These properties of the heat-treated samples were also evaluated in a temperature range of 20 to 250 degrees C in the presence of electrical stress of 60 Hz, 50 V/mil. The AC and DC breakdown strengths of both dry and impregnated samples were determined at ambient conditions. The preliminary data indicate that heat treatment of the materials tested improves their dielectric properties and breakdown voltages. The AC and DC dielectric strengths are further improved upon impregnation with a suitable liquid.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"47 1","pages":"459-464"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90580146","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.1989.69594
D. Raghavender, M. Naidu
A comprehensive study has been carried out in SF/sub 6//CCl/sub 2/F/sub 2//CO/sub 2/ mixtures to measure 50% breakdown voltages V/sub 50/ using both positive and negative polarity lightning impulse (1.2/50 mu s) voltages under nonuniform fields (5-mm rod, 230-mm plane electrode) over a pressure range of 0.1 to 0.5 MPa for a gap spacing of 20 mm. The sum of SF/sub 6/ and CCl/sub 2/F/sub 2/ concentrations in the mixture was always maintained in the range of 21 to 40%, the rest being CO/sub 2/. Among the different sets of SF/sub 6//CCl/sub 2/F/sub 2//CO/sub 2/ mixtures studied, two ternary mixtures, namely 20% SF/sub 6//20% CCl/sub 2/F/sub 2//60% CO/sub 2/ and 30% SF/sub 6//10% CCl/sub 2/F/sub 2//60% CO/sub 2/, were found superior to SF/sub 6/. From the known gas content in the mixtures and from the measured breakdown voltages, a cost/benefit analysis has been carried out for the various mixtures investigated. A striking feature of this analysis is that the most promising ternary gas mixture, namely 30% SF/sub 6//10% CCl/sub 2/-F/sub 2//60% CO/sub 2/, costs only 33% as much as pure SF/sub 6/, giving 100% to 170% positive breakdown strength, and 90 to 100% negative breakdown strength as compared to that of pure SF/sub 6/.<>
{"title":"Impulse breakdown characteristics and cost/benefit analysis of SF/sub 6//CCl/sub 2/F/sub 2//CO/sub 2/ mixtures","authors":"D. Raghavender, M. Naidu","doi":"10.1109/CEIDP.1989.69594","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69594","url":null,"abstract":"A comprehensive study has been carried out in SF/sub 6//CCl/sub 2/F/sub 2//CO/sub 2/ mixtures to measure 50% breakdown voltages V/sub 50/ using both positive and negative polarity lightning impulse (1.2/50 mu s) voltages under nonuniform fields (5-mm rod, 230-mm plane electrode) over a pressure range of 0.1 to 0.5 MPa for a gap spacing of 20 mm. The sum of SF/sub 6/ and CCl/sub 2/F/sub 2/ concentrations in the mixture was always maintained in the range of 21 to 40%, the rest being CO/sub 2/. Among the different sets of SF/sub 6//CCl/sub 2/F/sub 2//CO/sub 2/ mixtures studied, two ternary mixtures, namely 20% SF/sub 6//20% CCl/sub 2/F/sub 2//60% CO/sub 2/ and 30% SF/sub 6//10% CCl/sub 2/F/sub 2//60% CO/sub 2/, were found superior to SF/sub 6/. From the known gas content in the mixtures and from the measured breakdown voltages, a cost/benefit analysis has been carried out for the various mixtures investigated. A striking feature of this analysis is that the most promising ternary gas mixture, namely 30% SF/sub 6//10% CCl/sub 2/-F/sub 2//60% CO/sub 2/, costs only 33% as much as pure SF/sub 6/, giving 100% to 170% positive breakdown strength, and 90 to 100% negative breakdown strength as compared to that of pure SF/sub 6/.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"9 1","pages":"489-494"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76356532","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.1989.69588
E. Husain, M. M. Mohsin, R. Nema
A simple equation of the form E=-A+B log/sub 10/ ( rho /sub v/)/( epsilon /sub r/).(tan delta ) to predict the electric strength of a solid insulating material using the ASTM electrode system has been proposed. The constant B has been obtained as a function of the thickness t of solid insulating materials. The equation requires the values of volume resistivity rho /sub v/, relative permittivity epsilon /sub r/, and dissipation factor tan delta of the material, which may be obtained easily by low-voltage nondestructive measurements. The values of electric strength calculated using this equation for polyethylene, fiberglass, leatheroid, mica, empire cloth, and polyethylene-coated leatheroid show an excellent agreement with the experimentally measured values when 0.15 mm>
{"title":"On electric strength of solid insulating materials","authors":"E. Husain, M. M. Mohsin, R. Nema","doi":"10.1109/CEIDP.1989.69588","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69588","url":null,"abstract":"A simple equation of the form E=-A+B log/sub 10/ ( rho /sub v/)/( epsilon /sub r/).(tan delta ) to predict the electric strength of a solid insulating material using the ASTM electrode system has been proposed. The constant B has been obtained as a function of the thickness t of solid insulating materials. The equation requires the values of volume resistivity rho /sub v/, relative permittivity epsilon /sub r/, and dissipation factor tan delta of the material, which may be obtained easily by low-voltage nondestructive measurements. The values of electric strength calculated using this equation for polyethylene, fiberglass, leatheroid, mica, empire cloth, and polyethylene-coated leatheroid show an excellent agreement with the experimentally measured values when 0.15 mm>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"39 1","pages":"453-458"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73695897","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.1989.69526
W. Pfeiffer, H. Welke, V. Zimmer
Measurements have been made to evaluate the characteristics of impulse corona at negative impulse stress. It is shown that for the parameters investigated the corona onset voltage is a linear function of the degree of homogeneity of the electrode arrangement for different pressures and mixture ratios. It is also shown that the corona onset voltage is a linear function of the pressure for different gap distances and mixture ratios for the parameters investigated. The breakdown voltage at impulse stress has been measured for a constant formative time lag, for different gap distances, for various degrees of homogeneity ( eta =E/sub mean//E/sub max/ was varied from 0.76 to 0.04), and for different SF/sub 6/-N/sub 2/ mixtures. Measurements of the breakdown voltage have shown that the corona stabilizing effect exists up to a mixture ratio of 10% SF/sub 6/ to N/sub 2/. It has been found that a slightly inhomogeneous electrode arrangement ( eta =0.26) has a lower dielectric strength than a strongly inhomogeneous electrode arrangement ( eta =0.04).<>
{"title":"Corona stabilization at negative impulse stress in SF/sub 6/ and SF/sub 6/-N/sub 2/-mixtures","authors":"W. Pfeiffer, H. Welke, V. Zimmer","doi":"10.1109/CEIDP.1989.69526","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69526","url":null,"abstract":"Measurements have been made to evaluate the characteristics of impulse corona at negative impulse stress. It is shown that for the parameters investigated the corona onset voltage is a linear function of the degree of homogeneity of the electrode arrangement for different pressures and mixture ratios. It is also shown that the corona onset voltage is a linear function of the pressure for different gap distances and mixture ratios for the parameters investigated. The breakdown voltage at impulse stress has been measured for a constant formative time lag, for different gap distances, for various degrees of homogeneity ( eta =E/sub mean//E/sub max/ was varied from 0.76 to 0.04), and for different SF/sub 6/-N/sub 2/ mixtures. Measurements of the breakdown voltage have shown that the corona stabilizing effect exists up to a mixture ratio of 10% SF/sub 6/ to N/sub 2/. It has been found that a slightly inhomogeneous electrode arrangement ( eta =0.26) has a lower dielectric strength than a strongly inhomogeneous electrode arrangement ( eta =0.04).<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"8 1","pages":"75-80"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79164678","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.1989.69541
H. Narushima, Y. Tsukamoto, J. Koshimura
Insulating reliability between adjacent leads formed on organic material is an important problem for printed circuits. This problem was investigated in connection with insulator deterioration between copper conductors exposed to high temperature and high humidity under fairly high electric fields in comparison with actual operating conditions. The investigation was performed on a copper foil laminated to a thermoset adhesive coated on polyimide film. Abrupt and intermittent changes in leakage current were found to occur at high humidity and high temperature under field application. Before the abrupt change occurred, the corrosion expanded toward the cathode from the anode. Thereafter a copper component migrated to the cathode from the corrosion zone. The copper migration and the corrosion progressed through the adhesive, not along the surface. A similar failure phenomenon was observed for adhesives made of polyamide, epoxy, and phenolic resins, but their times to failure were quite different. This was attributed to their hydrolysis.<>
{"title":"Electrical aging of adhesive","authors":"H. Narushima, Y. Tsukamoto, J. Koshimura","doi":"10.1109/CEIDP.1989.69541","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69541","url":null,"abstract":"Insulating reliability between adjacent leads formed on organic material is an important problem for printed circuits. This problem was investigated in connection with insulator deterioration between copper conductors exposed to high temperature and high humidity under fairly high electric fields in comparison with actual operating conditions. The investigation was performed on a copper foil laminated to a thermoset adhesive coated on polyimide film. Abrupt and intermittent changes in leakage current were found to occur at high humidity and high temperature under field application. Before the abrupt change occurred, the corrosion expanded toward the cathode from the anode. Thereafter a copper component migrated to the cathode from the corrosion zone. The copper migration and the corrosion progressed through the adhesive, not along the surface. A similar failure phenomenon was observed for adhesives made of polyamide, epoxy, and phenolic resins, but their times to failure were quite different. This was attributed to their hydrolysis.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"392 1","pages":"168-172"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80432200","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.1989.69524
A. Jonscher
It is suggested that, in comparison with accepted theories, the energy criterion approach to the understanding of the 'universal' dielectric response offers a significantly better overall insight into the physical and chemical nature of the polarization processes deviating strongly from the classical Debye spectra. The ability to interpret the entire range of dielectric phenomena within a unified body of theory represents one of the chief attractions of the proposed approach, while the prospect of being able to understand the conditions for obtaining the various limiting forms of behavior such as low-frequency dispersion (LFD), 'flat loss', or near-Debye spectra, constitutes a distinctive advance on the current state of dielectric theory, which is not able to offer clear interpretations of the widely observed universal laws. It is noted that there may exist many physical mechanisms capable of satisfying the energy criterion, and the applicability of any one of these has to be judged in light of the nature of the process in question. The author proposes three such mechanisms, one for relatively lossy dipole and hopping charge carrier systems, another for low-loss nonpolymers, and a third for LFD processes in which there is a clear electrochemical connection.<>
{"title":"Energy criterion as the basis of the 'universal' dielectric response","authors":"A. Jonscher","doi":"10.1109/CEIDP.1989.69524","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69524","url":null,"abstract":"It is suggested that, in comparison with accepted theories, the energy criterion approach to the understanding of the 'universal' dielectric response offers a significantly better overall insight into the physical and chemical nature of the polarization processes deviating strongly from the classical Debye spectra. The ability to interpret the entire range of dielectric phenomena within a unified body of theory represents one of the chief attractions of the proposed approach, while the prospect of being able to understand the conditions for obtaining the various limiting forms of behavior such as low-frequency dispersion (LFD), 'flat loss', or near-Debye spectra, constitutes a distinctive advance on the current state of dielectric theory, which is not able to offer clear interpretations of the widely observed universal laws. It is noted that there may exist many physical mechanisms capable of satisfying the energy criterion, and the applicability of any one of these has to be judged in light of the nature of the process in question. The author proposes three such mechanisms, one for relatively lossy dipole and hopping charge carrier systems, another for low-loss nonpolymers, and a third for LFD processes in which there is a clear electrochemical connection.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"34 1","pages":"59-64"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85083024","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.1989.69529
P. McGrath, H. I. Marsden
An imaging system using shadow-graph optics in conjunction with a 3-ns-duration pulse laser was used to investigate prebreakdown events in DC and AC stressed n-hexane. The use of either DC or AC was shown to produce results that are essentially identical for a given electrode polarity. In addition, the prebreakdown images obtained bear a strong resemblance to those seen in impulse tests. This result suggests that prebreakdown events respond principally to the magnitude and polarity of the applied electric field, and that space charge and liquid motion exert minor influence.<>
{"title":"Prebreakdown events in DC and AC stressed n-hexane","authors":"P. McGrath, H. I. Marsden","doi":"10.1109/CEIDP.1989.69529","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69529","url":null,"abstract":"An imaging system using shadow-graph optics in conjunction with a 3-ns-duration pulse laser was used to investigate prebreakdown events in DC and AC stressed n-hexane. The use of either DC or AC was shown to produce results that are essentially identical for a given electrode polarity. In addition, the prebreakdown images obtained bear a strong resemblance to those seen in impulse tests. This result suggests that prebreakdown events respond principally to the magnitude and polarity of the applied electric field, and that space charge and liquid motion exert minor influence.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"2 1","pages":"93-98"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90559758","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.1989.69576
A. J. Morin, M. Zahn, J. Melcher
A novel Couette charger facility has been built to simulate flow electrification processes in transformers, where transformer oil fills the annulus between coaxial cylindrical electrodes that can be bare metal or transformer pressboard covered. Flow electrification charge density measurements as a function of inner cylinder speed have been performed using a newly developed absolute charge sensor (ACS) which brings a sample of fluid from the turbulent core into a Faraday cage and measures the total charge with no extraneous contributions from charge separated within the ACS itself. Transient measurements with a step change in temperature have shown the charge density to change from an initial to a new steady-state value. These charge density values depend on equilibrium moisture levels which in turn depend on the temperature. For all oils tested thus far with bare metal and T4 pressboard, the oil charge density is positive, but with HiVal pressboard there are some moisture and temperature regimes where the charge polarity reverses. The effects of transformer energization were also simulated by applying low-frequency (1 to 4 Hz) high voltages (field strength up to 1.8 kV/cm peak) across the cylinder of the Couette charger.<>
{"title":"Effects of temperature and moisture on flow electrification in transformer pressboard/oil insulation","authors":"A. J. Morin, M. Zahn, J. Melcher","doi":"10.1109/CEIDP.1989.69576","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69576","url":null,"abstract":"A novel Couette charger facility has been built to simulate flow electrification processes in transformers, where transformer oil fills the annulus between coaxial cylindrical electrodes that can be bare metal or transformer pressboard covered. Flow electrification charge density measurements as a function of inner cylinder speed have been performed using a newly developed absolute charge sensor (ACS) which brings a sample of fluid from the turbulent core into a Faraday cage and measures the total charge with no extraneous contributions from charge separated within the ACS itself. Transient measurements with a step change in temperature have shown the charge density to change from an initial to a new steady-state value. These charge density values depend on equilibrium moisture levels which in turn depend on the temperature. For all oils tested thus far with bare metal and T4 pressboard, the oil charge density is positive, but with HiVal pressboard there are some moisture and temperature regimes where the charge polarity reverses. The effects of transformer energization were also simulated by applying low-frequency (1 to 4 Hz) high voltages (field strength up to 1.8 kV/cm peak) across the cylinder of the Couette charger.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"5 1","pages":"384-385"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81429812","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.1989.69544
D. Das-Gupta, A. Goodings
The authors report results of an investigation of hydration isotherms and surface conductivity of PEEK (polyetheretherketone) as a function of relative humidity. Gamma irradiation of samples with radiation dose not exceeding 6 Mrad was performed both in air and in nitrogen. Typical behavior of surface currents at varying hydration for three different voltages are shown for the untreated PEEK film. The presence of water molecules on the polymer surfacer gives rise to surface conduction, the absorption behavior being naturally dependent on the surface characteristics of the material. Hydration isotherms of untreated and gamma-irradiated PEEK are shown from which it may be observed that there is a significant increase in the absorption of water after such treatment. It is suggested that the excess water absorption with irradiation occurs in the bulk of the polymer, the surface conductivity remaining, however, independent of the bulk effect.<>
{"title":"Surface conductivity of irradiated polymers in humid environment","authors":"D. Das-Gupta, A. Goodings","doi":"10.1109/CEIDP.1989.69544","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69544","url":null,"abstract":"The authors report results of an investigation of hydration isotherms and surface conductivity of PEEK (polyetheretherketone) as a function of relative humidity. Gamma irradiation of samples with radiation dose not exceeding 6 Mrad was performed both in air and in nitrogen. Typical behavior of surface currents at varying hydration for three different voltages are shown for the untreated PEEK film. The presence of water molecules on the polymer surfacer gives rise to surface conduction, the absorption behavior being naturally dependent on the surface characteristics of the material. Hydration isotherms of untreated and gamma-irradiated PEEK are shown from which it may be observed that there is a significant increase in the absorption of water after such treatment. It is suggested that the excess water absorption with irradiation occurs in the bulk of the polymer, the surface conductivity remaining, however, independent of the bulk effect.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"16 1","pages":"186-191"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84556858","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.1989.69531
J. Braun, J. Groeger
The gas contents of voids found in commercial epoxy spacers and laboratory samples are investigated as part of a broader investigation into the aging characteristics of GIS (gas-insulated switchgear) spacers. Gas chromatography techniques were successful in identifying permanent gases and organic vapors in epoxy spacers. Simple crushing and, where practical, drilling were used to release the gaseous effluents. Analyses performed on production epoxy spacers yielded predominantly nitrogen and oxygen with, in much smaller concentrations, uncured residues and curing by-products similar to those dissolved in the epoxy mass. Given the high temperatures at the time of formation of the cavities, diffusion processes in the liquid-like mass will establish rapid equilibrium between the voids and the surrounding epoxy mass. Control of the gas and pressure content in epoxy cavities is similarly difficult to achieve where desired because of diffusion effects in the curing mass. While oxygen depletion can be readily ascribed to reaction with the uncured epoxy, the presence of excess nitrogen cannot yet be explained satisfactorily.<>
{"title":"Determination of gases and gas pressure in GIS spacer voids","authors":"J. Braun, J. Groeger","doi":"10.1109/CEIDP.1989.69531","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69531","url":null,"abstract":"The gas contents of voids found in commercial epoxy spacers and laboratory samples are investigated as part of a broader investigation into the aging characteristics of GIS (gas-insulated switchgear) spacers. Gas chromatography techniques were successful in identifying permanent gases and organic vapors in epoxy spacers. Simple crushing and, where practical, drilling were used to release the gaseous effluents. Analyses performed on production epoxy spacers yielded predominantly nitrogen and oxygen with, in much smaller concentrations, uncured residues and curing by-products similar to those dissolved in the epoxy mass. Given the high temperatures at the time of formation of the cavities, diffusion processes in the liquid-like mass will establish rapid equilibrium between the voids and the surrounding epoxy mass. Control of the gas and pressure content in epoxy cavities is similarly difficult to achieve where desired because of diffusion effects in the curing mass. While oxygen depletion can be readily ascribed to reaction with the uncured epoxy, the presence of excess nitrogen cannot yet be explained satisfactorily.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"82 1","pages":"105-110"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90659755","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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