Pub Date : 1993-10-17DOI: 10.1109/CEIDP.1993.378883
A. Motori, G. Montanari, S. Gubanski
The results of thermally stimulated discharging current (TSDC) and DC isothermal charging/discharging current measurement, performed on pretreated and thermally aged XLPE (cross-linked polyethylene) cable models, are presented. A /spl beta/ relaxation, related to the glass-rubber transition of the amorphous region, and a high-temperature peak, likely due to charge polarization and related to the melting of the crystalline region, were found in the TSDC spectra. A TSDC peak with a maximum at 55/spl deg/C appeared with thermal aging. This process was also pointed out by isothermal discharging current measurement and was mainly ascribed to charge polarization. Correlations between the changes of intensity and temperature location of TSDC peaks with aging and changes of other properties as well (melting enthalpy and temperature, glass-transition temperature, etc.) were established.<>
{"title":"Investigation of relaxation processes in thermally-aged XLPE cable models","authors":"A. Motori, G. Montanari, S. Gubanski","doi":"10.1109/CEIDP.1993.378883","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378883","url":null,"abstract":"The results of thermally stimulated discharging current (TSDC) and DC isothermal charging/discharging current measurement, performed on pretreated and thermally aged XLPE (cross-linked polyethylene) cable models, are presented. A /spl beta/ relaxation, related to the glass-rubber transition of the amorphous region, and a high-temperature peak, likely due to charge polarization and related to the melting of the crystalline region, were found in the TSDC spectra. A TSDC peak with a maximum at 55/spl deg/C appeared with thermal aging. This process was also pointed out by isothermal discharging current measurement and was mainly ascribed to charge polarization. Correlations between the changes of intensity and temperature location of TSDC peaks with aging and changes of other properties as well (melting enthalpy and temperature, glass-transition temperature, etc.) were established.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121097278","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 : 1993-10-17DOI: 10.1109/CEIDP.1993.378978
T. Mizutani, Y. Suzuoki, A. Fujii, T. Suzuki
Direct and quantitative measurement of space charge was performed for PPS (poly-p-phenylene sulfide), and positive space charge was observed. In biaxially stretched semicrystalline PPS, homo space charge is formed near the anode, whereas, in unstretched amorphous PPS, space charge ranges almost uniformly throughout the sample. The amount and distribution of the detected space charges explain the effects of prestress on breakdown in these materials, suggesting that the breakdown does not always take place in the region with the highest local field. The dependence of space charge distribution on morphology corresponds to the difference in impulse breakdown strength and conduction current, and is explained by higher effective carrier mobility due to lower trap density in unstretched amorphous PPS.<>
{"title":"Space charge and electrical breakdown in polyphenylene sulfide films","authors":"T. Mizutani, Y. Suzuoki, A. Fujii, T. Suzuki","doi":"10.1109/CEIDP.1993.378978","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378978","url":null,"abstract":"Direct and quantitative measurement of space charge was performed for PPS (poly-p-phenylene sulfide), and positive space charge was observed. In biaxially stretched semicrystalline PPS, homo space charge is formed near the anode, whereas, in unstretched amorphous PPS, space charge ranges almost uniformly throughout the sample. The amount and distribution of the detected space charges explain the effects of prestress on breakdown in these materials, suggesting that the breakdown does not always take place in the region with the highest local field. The dependence of space charge distribution on morphology corresponds to the difference in impulse breakdown strength and conduction current, and is explained by higher effective carrier mobility due to lower trap density in unstretched amorphous PPS.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"15 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120844730","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 : 1993-10-17DOI: 10.1109/CEIDP.1993.378923
M. Farzaneh, J. Kiernicki, J. Drapeau
The influence of the physical aspect of ice accumulation and of water conductivity on the withstand voltage of high-voltage (HV) insulators was determined. Two cap-and-pin insulators and one column type insulator were subjected to flashover testing in a climate room. Artificial ice was accumulated from supercooled droplets at an air temperature of -12/spl deg/C. The electrical conductivity of the spray water between 5 and 150 /spl mu/S/cm was adjusted by adding sodium chloride to de-ionized water. The results obtained indicated that, under experimental conditions, the highest probability of flashover resulted from uniform ice accretion. The withstand voltage of the insulators decreased as the conductivity of the spray water increased. In addition, a series of outdoor camera observations made it possible to compare the aspects of ice accretion during actual freezing rain to those obtained in the laboratory.<>
{"title":"AC flashover performance of H.V. insulators under glaze and rime","authors":"M. Farzaneh, J. Kiernicki, J. Drapeau","doi":"10.1109/CEIDP.1993.378923","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378923","url":null,"abstract":"The influence of the physical aspect of ice accumulation and of water conductivity on the withstand voltage of high-voltage (HV) insulators was determined. Two cap-and-pin insulators and one column type insulator were subjected to flashover testing in a climate room. Artificial ice was accumulated from supercooled droplets at an air temperature of -12/spl deg/C. The electrical conductivity of the spray water between 5 and 150 /spl mu/S/cm was adjusted by adding sodium chloride to de-ionized water. The results obtained indicated that, under experimental conditions, the highest probability of flashover resulted from uniform ice accretion. The withstand voltage of the insulators decreased as the conductivity of the spray water increased. In addition, a series of outdoor camera observations made it possible to compare the aspects of ice accretion during actual freezing rain to those obtained in the laboratory.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123029428","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 : 1993-10-17DOI: 10.1109/CEIDP.1993.378924
B. Pahlavanpour, G. Duffy
Furfuraldehyde (FFA) has been measured colorimetrically in gas oil and hydrocarbon oil. The method is based on reaction between FFA and aniline acetate solution to produce a bright pink color. The intensity of the color is measured spectrophotometrically. This rapid technique of color development was applied to the determination of FFA in transformer oil. The method is sensitive to sub-ppm FFA in transformer oil. The results are comparable with those obtained using the high-performance liquid chromatography method.<>
{"title":"Development of a rapid spectrophotometry method for analysis of furfuraldehyde in transformer oil as an indication of paper ageing","authors":"B. Pahlavanpour, G. Duffy","doi":"10.1109/CEIDP.1993.378924","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378924","url":null,"abstract":"Furfuraldehyde (FFA) has been measured colorimetrically in gas oil and hydrocarbon oil. The method is based on reaction between FFA and aniline acetate solution to produce a bright pink color. The intensity of the color is measured spectrophotometrically. This rapid technique of color development was applied to the determination of FFA in transformer oil. The method is sensitive to sub-ppm FFA in transformer oil. The results are comparable with those obtained using the high-performance liquid chromatography method.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121779761","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 : 1993-10-17DOI: 10.1109/CEIDP.1993.378879
J. Parpal, É. David, G. Delmas, H. Phuong-Nguyen
The authors present preliminary DSC (differential scanning calorimetry) results obtained on XLPE (cross-linked polyethylene) cable insulation at low and high rates of heating/cooling for unaged and electrically aged samples characterized in terms of their birefringence pattern. Some measurements were made under dry conditions while some results are presented for samples in cyclopentane. The DSC measurements at 3-6 K/h (0.05-0.1 K/min) heating/cooling rate show a reversible endotherm above the melt temperature of the orthorhombic phase. This post-melting peak cannot be observed at the conventional DSC heating/cooling rate of 6-10 K/min but it is observable at lower temperatures when the XLPE samples are put in cyclopentane. The effects are associated with order-disorder transitions in strained networks.<>
{"title":"DSC measurements on XLPE cables at low and high heating/cooling rates","authors":"J. Parpal, É. David, G. Delmas, H. Phuong-Nguyen","doi":"10.1109/CEIDP.1993.378879","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378879","url":null,"abstract":"The authors present preliminary DSC (differential scanning calorimetry) results obtained on XLPE (cross-linked polyethylene) cable insulation at low and high rates of heating/cooling for unaged and electrically aged samples characterized in terms of their birefringence pattern. Some measurements were made under dry conditions while some results are presented for samples in cyclopentane. The DSC measurements at 3-6 K/h (0.05-0.1 K/min) heating/cooling rate show a reversible endotherm above the melt temperature of the orthorhombic phase. This post-melting peak cannot be observed at the conventional DSC heating/cooling rate of 6-10 K/min but it is observable at lower temperatures when the XLPE samples are put in cyclopentane. The effects are associated with order-disorder transitions in strained networks.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127198475","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 : 1993-10-17DOI: 10.1109/CEIDP.1993.378944
H. Sakurai, T. Ueta, S. Itahashi, H. Mitsui, M. Sone
The effect of trimer water cluster on conduction phenomena was investigated using three kinds of liquid dielectrics: di-octhyle-phthalate (DOP), including dimer; acctonitrile (ACT), including dimer and much trimer; and a mixture of ACT and DOP. It is shown that, when the concentration of DOP in the mixture increases, the amount of trimer decreases and the cluster becomes smaller. In the conduction test, it is evident that the conduction current is electron current. It is also shown that, as the amount of trimer decreases and the cluster becomes smaller, the electron current decreases. This conduction phenomena appears to be due to trimer bridges.<>
{"title":"Influence of trimer water cluster in liquid materials on conduction phenomena by using nano-second pulse","authors":"H. Sakurai, T. Ueta, S. Itahashi, H. Mitsui, M. Sone","doi":"10.1109/CEIDP.1993.378944","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378944","url":null,"abstract":"The effect of trimer water cluster on conduction phenomena was investigated using three kinds of liquid dielectrics: di-octhyle-phthalate (DOP), including dimer; acctonitrile (ACT), including dimer and much trimer; and a mixture of ACT and DOP. It is shown that, when the concentration of DOP in the mixture increases, the amount of trimer decreases and the cluster becomes smaller. In the conduction test, it is evident that the conduction current is electron current. It is also shown that, as the amount of trimer decreases and the cluster becomes smaller, the electron current decreases. This conduction phenomena appears to be due to trimer bridges.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"196 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134496882","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 : 1993-10-17DOI: 10.1109/CEIDP.1993.378982
D. Moya-Siesse, G. Moya, C. Legressus, G. Blaise
A system able to measure in situ, after charging by an electron beam in a SEM, the energy released for small-sized dielectrics is described. The device observe the phenomena of breakdown during detrapping. Preliminary calibration by the Joule effect and by a laser irradiation technique has shown that the sensitivity of the device presently corresponds, through an amplifier, to an analog signal, giving a deviation of 0.70 /spl mu/Watt/mm. The nature of the thermal event (endothermic or exothermic) can be established by focusing the electron beam on the grounded steel sheet before implantation. Preliminary results show that an exothermic signal may occur during the event produced by the charge detrapping breakdown, whereas a slow detrapping cannot be detected.<>
{"title":"Energy released during space charge relaxation induced breakdown","authors":"D. Moya-Siesse, G. Moya, C. Legressus, G. Blaise","doi":"10.1109/CEIDP.1993.378982","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378982","url":null,"abstract":"A system able to measure in situ, after charging by an electron beam in a SEM, the energy released for small-sized dielectrics is described. The device observe the phenomena of breakdown during detrapping. Preliminary calibration by the Joule effect and by a laser irradiation technique has shown that the sensitivity of the device presently corresponds, through an amplifier, to an analog signal, giving a deviation of 0.70 /spl mu/Watt/mm. The nature of the thermal event (endothermic or exothermic) can be established by focusing the electron beam on the grounded steel sheet before implantation. Preliminary results show that an exothermic signal may occur during the event produced by the charge detrapping breakdown, whereas a slow detrapping cannot be detected.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"17 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133622860","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 : 1993-10-17DOI: 10.1109/CEIDP.1993.378967
J. Ganachaud, A. Mokrani
A Monte-Carlo simulation model has been constructed to describe the secondary electron emission of insulator targets. It accounts for the different electron insulator elementary processes. Other aspects relevant to recent developments in the field of space charge physics (distribution of polaron trapping sites, field distribution, etc.) are also included. The conclusions obtained by this method are in good agreement with experimental observations. The study suggests that a realistic simulation model, including elastic effects, the existence of defects and polaron trapping sites and the effect of the electrostatic field, is necessary in order to account for the measured values of the secondary yield in an insulator target like alumina.<>
{"title":"Study of the secondary electron emission of insulators by a Monte-Carlo simulation method","authors":"J. Ganachaud, A. Mokrani","doi":"10.1109/CEIDP.1993.378967","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378967","url":null,"abstract":"A Monte-Carlo simulation model has been constructed to describe the secondary electron emission of insulator targets. It accounts for the different electron insulator elementary processes. Other aspects relevant to recent developments in the field of space charge physics (distribution of polaron trapping sites, field distribution, etc.) are also included. The conclusions obtained by this method are in good agreement with experimental observations. The study suggests that a realistic simulation model, including elastic effects, the existence of defects and polaron trapping sites and the effect of the electrostatic field, is necessary in order to account for the measured values of the secondary yield in an insulator target like alumina.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"11 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132737399","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 : 1993-10-17DOI: 10.1109/CEIDP.1993.378882
M. Ishida, T. Okamoto
The direct observation of the microscopic morphology of cross-linked polyethylene (XLPE) insulations, performed by a field-emission transmission scanning electron microscope (FE-STEM), which combines a new field emission-type electron source and electron beam scanning. It has been found that the spherulite structures (subtle density difference) in unstained XLPE insulations can be observed in terms of the difference in contrast by means of the FE-STEM method. The density of spherulite structures in the XLPE insulation is higher than that of the regions between spherulites. These spherulite structures are dispersed and do not have clear borders.<>
{"title":"Direct observation technique of XLPE morphology through the FE-STEM method","authors":"M. Ishida, T. Okamoto","doi":"10.1109/CEIDP.1993.378882","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378882","url":null,"abstract":"The direct observation of the microscopic morphology of cross-linked polyethylene (XLPE) insulations, performed by a field-emission transmission scanning electron microscope (FE-STEM), which combines a new field emission-type electron source and electron beam scanning. It has been found that the spherulite structures (subtle density difference) in unstained XLPE insulations can be observed in terms of the difference in contrast by means of the FE-STEM method. The density of spherulite structures in the XLPE insulation is higher than that of the regions between spherulites. These spherulite structures are dispersed and do not have clear borders.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128917509","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 : 1993-10-17DOI: 10.1109/CEIDP.1993.378976
M. Khalil
A thermal step method was used to investigate space charge formation in low-density polyethylene (LDPE) and LDPE doped with an inorganic additive. Space charge was formed at a field of about 3.3 /spl times/ 10/sup 5/ Vcm/sup -1/ and at two different temperatures, 40/spl deg/C and 70/spl deg/C. Results indicate that the addition of such an additive considerably reduced the density of the remnant space charge in the doped material and appreciably changed its distribution pattern. It is also shown that the remnant space charge in the doped material is sensitive to the forming temperature, while in the plain material the space charge appears to be insensitive to the change of temperature within the temperature range used.<>
{"title":"Effect of additive and polarization temperature on space charge formation in polyethylene","authors":"M. Khalil","doi":"10.1109/CEIDP.1993.378976","DOIUrl":"https://doi.org/10.1109/CEIDP.1993.378976","url":null,"abstract":"A thermal step method was used to investigate space charge formation in low-density polyethylene (LDPE) and LDPE doped with an inorganic additive. Space charge was formed at a field of about 3.3 /spl times/ 10/sup 5/ Vcm/sup -1/ and at two different temperatures, 40/spl deg/C and 70/spl deg/C. Results indicate that the addition of such an additive considerably reduced the density of the remnant space charge in the doped material and appreciably changed its distribution pattern. It is also shown that the remnant space charge in the doped material is sensitive to the forming temperature, while in the plain material the space charge appears to be insensitive to the change of temperature within the temperature range used.<<ETX>>","PeriodicalId":149803,"journal":{"name":"Proceedings of IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP '93)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127133002","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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