Pub Date : 2008-10-31DOI: 10.1109/ISEIM.2008.4664595
S.T. Li, Y. Yang
CaCu3Ti4O12 were prepared using conventional solid state reaction processing techniques. The structure of CaCu3Ti4O12 was confirmed by X-ray diffraction. The microstructure with various grain sizes was characterized by scanning electron microscopy. Different element distributing between grain and grain boundary was detected by energy dispersive X-ray spectrometer. The dielectric spectrum was measured at room temperature. The I-V characteristics of CaCu3Ti4O12 were measured in a wide temperature range from 93 K to 373 K. It is found that the nonlinear coefficient varies with temperature and the total conductance can be separated into three parts at various current. The nonlinear coefficient corresponding to each part can be deduced from the conductance-current curve, and then the temperature dependence of the nonlinear coefficient can be explained.
{"title":"Conduction properties of CaCu3Ti4O12","authors":"S.T. Li, Y. Yang","doi":"10.1109/ISEIM.2008.4664595","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664595","url":null,"abstract":"CaCu<sub>3</sub>Ti<sub>4</sub>O<sub>12</sub> were prepared using conventional solid state reaction processing techniques. The structure of CaCu<sub>3</sub>Ti<sub>4</sub>O<sub>12</sub> was confirmed by X-ray diffraction. The microstructure with various grain sizes was characterized by scanning electron microscopy. Different element distributing between grain and grain boundary was detected by energy dispersive X-ray spectrometer. The dielectric spectrum was measured at room temperature. The I-V characteristics of CaCu<sub>3</sub>Ti<sub>4</sub>O<sub>12</sub> were measured in a wide temperature range from 93 K to 373 K. It is found that the nonlinear coefficient varies with temperature and the total conductance can be separated into three parts at various current. The nonlinear coefficient corresponding to each part can be deduced from the conductance-current curve, and then the temperature dependence of the nonlinear coefficient can be explained.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130171444","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664548
K. Shinyama, S. Fujita
Polylactic acid (PLA), a biodegradable plastic, has excellent electrical insulation properties. Being a hard resin, however, PLA is difficult to apply to coated cable. In this study, we blended a plasticizer with PLA to soften it, and examined the effects of the plasticizer on the mechanical and electrical characteristics of PLA. The glass transition temperature (Tg) and the melting point (Tm) had a tendency to decrease with an increase in the amount of plasticizer. With an increase in the amount of plasticizer, the tensile strength had a tendency to decrease and the breaking elongation to increase. As described above, PLA became softer with an increase in the amount of plasticizer. At 298 K, dielectric breakdown strength (EB) was about 5 MV/cm, irrespective of the presence of the plasticizer; the plasticizer showed almost no effect on EB. At 353 K, however, EB had a tendency to increase with an increase in the amount of plasticizer.
{"title":"The effects of plasticizer on the mechanical and electrical characteristics of PLA","authors":"K. Shinyama, S. Fujita","doi":"10.1109/ISEIM.2008.4664548","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664548","url":null,"abstract":"Polylactic acid (PLA), a biodegradable plastic, has excellent electrical insulation properties. Being a hard resin, however, PLA is difficult to apply to coated cable. In this study, we blended a plasticizer with PLA to soften it, and examined the effects of the plasticizer on the mechanical and electrical characteristics of PLA. The glass transition temperature (Tg) and the melting point (Tm) had a tendency to decrease with an increase in the amount of plasticizer. With an increase in the amount of plasticizer, the tensile strength had a tendency to decrease and the breaking elongation to increase. As described above, PLA became softer with an increase in the amount of plasticizer. At 298 K, dielectric breakdown strength (EB) was about 5 MV/cm, irrespective of the presence of the plasticizer; the plasticizer showed almost no effect on EB. At 353 K, however, EB had a tendency to increase with an increase in the amount of plasticizer.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130542998","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664525
Y. Hayashi, T. Kato, Y. Suzuoki, F. Komori, N. Hayashi
In order to clarify the mechanism of electrical-tree inception and propagation from a water tree within polyethylene, we have investigated temperature dependence of water tree and electrical tree inception and propagation from water-tree degradation. In the samples with water tree of the area above ca. 5000 mum2, the ac electrical-tree inception voltage increased with increasing water-tree degradation in high temperature as well as room temperature. This is explained by the moderation of electrical field in the region of water tree. In the samples with water tree of the area less than 5000 mum2 and in the samples without water tree, however, the ac electrical-tree inception voltage is higher at 70degC than at room temperature and ca. 15 kVrms regardless of water-tree area. On the other hand, the samples with dried water tree degradation show reduction in impulse tree inception voltage by ac prestressing at 70degC. Moreover, at 90degC the rate of water-tree growth and the extent of degradation is much higher than at 30degC. This suggests possible danger of water tree degradation at high temperatures.
{"title":"Temperature dependence of electrical tree inception from water tree degradation","authors":"Y. Hayashi, T. Kato, Y. Suzuoki, F. Komori, N. Hayashi","doi":"10.1109/ISEIM.2008.4664525","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664525","url":null,"abstract":"In order to clarify the mechanism of electrical-tree inception and propagation from a water tree within polyethylene, we have investigated temperature dependence of water tree and electrical tree inception and propagation from water-tree degradation. In the samples with water tree of the area above ca. 5000 mum2, the ac electrical-tree inception voltage increased with increasing water-tree degradation in high temperature as well as room temperature. This is explained by the moderation of electrical field in the region of water tree. In the samples with water tree of the area less than 5000 mum2 and in the samples without water tree, however, the ac electrical-tree inception voltage is higher at 70degC than at room temperature and ca. 15 kVrms regardless of water-tree area. On the other hand, the samples with dried water tree degradation show reduction in impulse tree inception voltage by ac prestressing at 70degC. Moreover, at 90degC the rate of water-tree growth and the extent of degradation is much higher than at 30degC. This suggests possible danger of water tree degradation at high temperatures.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129181442","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664453
M. Onoda, Y. Abe, K. Tada
The preparation of acetonitrile-toluene suspension and the electrophoretic deposition of poly(9,9-dioctyfluorenyl-2,7-yleneethynylene) have been carried out. It was found that the size of colloidal particles in the acetonitrile-toluene suspension increases with decreasing toluene content. Atomic force microscopy (AFM) observation clearly indicated that a polymer film deposited from a suspension with a low toluene content consists of the large particles, reflecting the colloidal size in the parent suspension. A simple recipe for controlling average size of the colloidal particles in the nanostructured film mentioned here, which involves changing the nonsolvent : solvent ratio, may be useful for contolling the nanoporosity of the film, which is very important in optoelectronic, electronic, and electrochemical applications.
{"title":"Controlling the collidal size of conducting polymers","authors":"M. Onoda, Y. Abe, K. Tada","doi":"10.1109/ISEIM.2008.4664453","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664453","url":null,"abstract":"The preparation of acetonitrile-toluene suspension and the electrophoretic deposition of poly(9,9-dioctyfluorenyl-2,7-yleneethynylene) have been carried out. It was found that the size of colloidal particles in the acetonitrile-toluene suspension increases with decreasing toluene content. Atomic force microscopy (AFM) observation clearly indicated that a polymer film deposited from a suspension with a low toluene content consists of the large particles, reflecting the colloidal size in the parent suspension. A simple recipe for controlling average size of the colloidal particles in the nanostructured film mentioned here, which involves changing the nonsolvent : solvent ratio, may be useful for contolling the nanoporosity of the film, which is very important in optoelectronic, electronic, and electrochemical applications.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121321468","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664462
Y. Ehara, K. Suenaga, Yasuhiro Yoshioka, T. Kurihara
30 to 40 years have passed since cables and electric power apparatus were installed in the high-growth period of the Japanese economy, a lot of them have reached their design lifetimes and the time replace. On the other hand, it is requested because of the cost reduction in the operation of the power equipment that the degradation of these electric power apparatus is understood and the loss due to the breakdown is prevented beforehand. Moreover, it is strongly requested to use the electric power apparatus for the life limit.
{"title":"Digest report of the investigation committee on degradation diagnosis technology based on characteristics of insulation materials in electric power apparatus","authors":"Y. Ehara, K. Suenaga, Yasuhiro Yoshioka, T. Kurihara","doi":"10.1109/ISEIM.2008.4664462","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664462","url":null,"abstract":"30 to 40 years have passed since cables and electric power apparatus were installed in the high-growth period of the Japanese economy, a lot of them have reached their design lifetimes and the time replace. On the other hand, it is requested because of the cost reduction in the operation of the power equipment that the degradation of these electric power apparatus is understood and the loss due to the breakdown is prevented beforehand. Moreover, it is strongly requested to use the electric power apparatus for the life limit.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123099688","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664450
J. Ramajothi, S. Ochiai, K. Kojima, T. Mizutani
Organic field effect transistors (OFETs) were fabricated with high-kappa titanium dioxide (TiO2) as gate insulator and regioregular poly(3-hexylthiophene-2,5-diyl) (RR-P3HT) as electronically active semiconductor. The dielectric material was prepared by sol-gel method and the gate insulator layer was fabricated by spin-coating method. The thickness of the thin films was measured using surface profile measuring system. The fabricated thin films structure was analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-visible absorption spectra. The X-ray result shows that the drop-cast RR-P3HT thin film has high crystallinity on the TiO2 surface and leads to high field effect mobility of the OFET. Good characteristics performances were obtained with low threshold voltage (+3 V) and the field effect mobility is 3.73 times 10-3 cm2/Vs.
{"title":"Performance of poly(3-hexylthiophene) field effect transistor with high dielectric constant gate insulator","authors":"J. Ramajothi, S. Ochiai, K. Kojima, T. Mizutani","doi":"10.1109/ISEIM.2008.4664450","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664450","url":null,"abstract":"Organic field effect transistors (OFETs) were fabricated with high-kappa titanium dioxide (TiO2) as gate insulator and regioregular poly(3-hexylthiophene-2,5-diyl) (RR-P3HT) as electronically active semiconductor. The dielectric material was prepared by sol-gel method and the gate insulator layer was fabricated by spin-coating method. The thickness of the thin films was measured using surface profile measuring system. The fabricated thin films structure was analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-visible absorption spectra. The X-ray result shows that the drop-cast RR-P3HT thin film has high crystallinity on the TiO2 surface and leads to high field effect mobility of the OFET. Good characteristics performances were obtained with low threshold voltage (+3 V) and the field effect mobility is 3.73 times 10-3 cm2/Vs.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125094061","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664567
S. Mitsumoto, M. Nagao, M. Fu, L. Dissado, J. Fothergill
Polyethylene is a material that is widely used as insulation for power cables. In this paper, the effect of temperature and voltage application time on space charge decay in HDPE is described. Negative charge was found to be retained by the samples when a field of 50kV/mm was applied at temperatures of 25 and 40 degC, with an amount that increased with increasing voltage application time. The same field applied for 4800s at 60degC gave both negative and positive space charge, but only positive charge at 90 degC The decay time of the negative charge increased as the amount of negative space charge retained after voltage removal increased. This indicates that much of the trapped negative charge could not be de-trapped easily. In contrast positive space charge was observed following the application of 180 kV/mm and 300kV/mm. The speed of positive charge decay in these cases was much faster than that of the negative charge accumulated under 50kV/mm. It was also observed that the decay time of positive charge decreased with increases in the cathode field measured just before short-circuiting at 25 and 40degC, but not at 60 and 90degC.
{"title":"Effect of temperature and voltage application time on space charge decay of HDPE","authors":"S. Mitsumoto, M. Nagao, M. Fu, L. Dissado, J. Fothergill","doi":"10.1109/ISEIM.2008.4664567","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664567","url":null,"abstract":"Polyethylene is a material that is widely used as insulation for power cables. In this paper, the effect of temperature and voltage application time on space charge decay in HDPE is described. Negative charge was found to be retained by the samples when a field of 50kV/mm was applied at temperatures of 25 and 40 degC, with an amount that increased with increasing voltage application time. The same field applied for 4800s at 60degC gave both negative and positive space charge, but only positive charge at 90 degC The decay time of the negative charge increased as the amount of negative space charge retained after voltage removal increased. This indicates that much of the trapped negative charge could not be de-trapped easily. In contrast positive space charge was observed following the application of 180 kV/mm and 300kV/mm. The speed of positive charge decay in these cases was much faster than that of the negative charge accumulated under 50kV/mm. It was also observed that the decay time of positive charge decreased with increases in the cathode field measured just before short-circuiting at 25 and 40degC, but not at 60 and 90degC.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"42 11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114297271","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664585
Y. Muramoto, S. Mizuno, T. Mito, N. Shimizu
Electroluminescence (EL) occurs in initiation phase of electrical tree and is considered to be a probe of the degradation of polymer insulating materials. We consider that EL is caused by electron impact; namely, electrons injected from electrode are accelerated in micro cavity of sub-micron size and causes bond scission and excitation of luminescence center. Under existence of water, water treeing takes place when subjected to a high electric field. Water tree provides a starting point of electrical tree, and therefore is responsible for the final breakdown of power cables with polymeric insulation. But the relation between EL and degradation in water-treed region is still unclear. We studied the EL properties of cross-linked polyethylene (XLPE) with a water-treed region after drying process. Wepsilall discuss the relation between EL properties and progress of material degradation in water treed region.
{"title":"Electroluminescence properties of water-treed XLPE under long time voltage application","authors":"Y. Muramoto, S. Mizuno, T. Mito, N. Shimizu","doi":"10.1109/ISEIM.2008.4664585","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664585","url":null,"abstract":"Electroluminescence (EL) occurs in initiation phase of electrical tree and is considered to be a probe of the degradation of polymer insulating materials. We consider that EL is caused by electron impact; namely, electrons injected from electrode are accelerated in micro cavity of sub-micron size and causes bond scission and excitation of luminescence center. Under existence of water, water treeing takes place when subjected to a high electric field. Water tree provides a starting point of electrical tree, and therefore is responsible for the final breakdown of power cables with polymeric insulation. But the relation between EL and degradation in water-treed region is still unclear. We studied the EL properties of cross-linked polyethylene (XLPE) with a water-treed region after drying process. Wepsilall discuss the relation between EL properties and progress of material degradation in water treed region.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"405 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122786894","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664461
H. Homma, T. Tokoro, Y. Hirano, M. Ueda
Application of polymeric insulators has been expanded in the filed of power supply and distribution system all over the world. Compared to porcelain insulators, however, polymeric insulators have been demanded to solve the challenging subjects on a long-term reliability and diagnosis techniques in the real application field.
{"title":"Digest report on the investigation committee on surface properties and long-term performance of polymeric insulating materials for outdoor use","authors":"H. Homma, T. Tokoro, Y. Hirano, M. Ueda","doi":"10.1109/ISEIM.2008.4664461","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664461","url":null,"abstract":"Application of polymeric insulators has been expanded in the filed of power supply and distribution system all over the world. Compared to porcelain insulators, however, polymeric insulators have been demanded to solve the challenging subjects on a long-term reliability and diagnosis techniques in the real application field.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122797835","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664444
S. Gopalakrishna, M. Ilampoornan, V. Jayashankar
The mechanical strength and integrity of the transformer windings is established by short circuit test. Reactance comparison method and frequency response analysis methods are conventionally used to assess the failures. Concurrent application of various high frequency excitations has also been tested. We show that optimized multisine excitation has the potential of high sensitivity towards displacement identification.
{"title":"Sensitive method for detection of winding deformation during short circuit test","authors":"S. Gopalakrishna, M. Ilampoornan, V. Jayashankar","doi":"10.1109/ISEIM.2008.4664444","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664444","url":null,"abstract":"The mechanical strength and integrity of the transformer windings is established by short circuit test. Reactance comparison method and frequency response analysis methods are conventionally used to assess the failures. Concurrent application of various high frequency excitations has also been tested. We show that optimized multisine excitation has the potential of high sensitivity towards displacement identification.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128124509","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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