The mechanism of conduction between a Ta/sub 2/O/sub 5/ film and a metal electrode was studied by means of photocurrent measurements. The nature of the metal/Ta/sub 2/O/sub 5/ interface is shown as well as the energy diagram deduced from the results. Transient current decaying with time has been observed in the Al/Ta/sub 2/O/sub 5/ interface and explained in terms of the space charge effect due to the blocking barrier of Al/sub 2/O/sub 3/ formed at the interface.<>
{"title":"Transient photocurrents in tantalum pentoxide films","authors":"K. Miyairi","doi":"10.1109/ICSD.1989.69179","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69179","url":null,"abstract":"The mechanism of conduction between a Ta/sub 2/O/sub 5/ film and a metal electrode was studied by means of photocurrent measurements. The nature of the metal/Ta/sub 2/O/sub 5/ interface is shown as well as the energy diagram deduced from the results. Transient current decaying with time has been observed in the Al/Ta/sub 2/O/sub 5/ interface and explained in terms of the space charge effect due to the blocking barrier of Al/sub 2/O/sub 3/ formed at the interface.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129537535","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}
Experiments were conducted on samples of four types of PET (polyethylene terephthalate) film from two different manufacturers. The thermal aging of the PET films was shown to have a complex nature, expressed most markedly during the TSD measurements by changes of the space-charge peak maximum value. This behavior was found for all types of film. The peak change rate can be represented as a linear function of both the aging temperature and the expected time to withstand that thermal stress, estimated on the basis of the IEC 216 standard test. It is not possible at the present stage of study to estimate directly from the TSD measurements an equivalent to the temperature index, despite an existing correlation. Therefore, the method seems to be suitable for accelerated periodic monitoring of PET films whose thermal endurance characteristics are already known.<>
{"title":"On the possibility of the TSD measuring techniques application for PET films thermal endurance estimation","authors":"A. Gubanski, S. Gubanski","doi":"10.1109/ICSD.1989.69200","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69200","url":null,"abstract":"Experiments were conducted on samples of four types of PET (polyethylene terephthalate) film from two different manufacturers. The thermal aging of the PET films was shown to have a complex nature, expressed most markedly during the TSD measurements by changes of the space-charge peak maximum value. This behavior was found for all types of film. The peak change rate can be represented as a linear function of both the aging temperature and the expected time to withstand that thermal stress, estimated on the basis of the IEC 216 standard test. It is not possible at the present stage of study to estimate directly from the TSD measurements an equivalent to the temperature index, despite an existing correlation. Therefore, the method seems to be suitable for accelerated periodic monitoring of PET films whose thermal endurance characteristics are already known.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"447 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123874307","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}
M. Nagao, T. Kitamura, Y. Mizuno, M. Kosaki, M. Ieda
The contribution of the thermal process to DC electrical breakdown of polyethylene films at room temperature was investigated along with the character and the distribution of the weak points in the films. Local Joule heating in polyethylene film was detected before DC electrical breakdown at room temperature. When a high-temperature point appeared in a film, the conduction current increased with time. An analysis of the time variation of the conduction current and the temperature rise showed that the current flows mainly around the high-temperature point. The final breakdown occurred at the point of the highest temperature. The concurrence of the breakdown point and the Joule heating point suggests that a thermal process takes part in the DC electrical breakdown of polyethylene films at room temperature and that the weak points leading to the breakdown in the film occur where the current density is higher than the average. Local electromechanical deformation also appears to contribute to the DC electrical breakdown of polyethylene.<>
{"title":"Localized heat generation before dielectric breakdown of polyethylene films","authors":"M. Nagao, T. Kitamura, Y. Mizuno, M. Kosaki, M. Ieda","doi":"10.1109/ICSD.1989.69165","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69165","url":null,"abstract":"The contribution of the thermal process to DC electrical breakdown of polyethylene films at room temperature was investigated along with the character and the distribution of the weak points in the films. Local Joule heating in polyethylene film was detected before DC electrical breakdown at room temperature. When a high-temperature point appeared in a film, the conduction current increased with time. An analysis of the time variation of the conduction current and the temperature rise showed that the current flows mainly around the high-temperature point. The final breakdown occurred at the point of the highest temperature. The concurrence of the breakdown point and the Joule heating point suggests that a thermal process takes part in the DC electrical breakdown of polyethylene films at room temperature and that the weak points leading to the breakdown in the film occur where the current density is higher than the average. Local electromechanical deformation also appears to contribute to the DC electrical breakdown of polyethylene.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124420333","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}
The authors have shown previously (1987) that a thin layer of plasma-polymerized ethylene deposited on the surface of high-density polyethylene suppresses the injection of carriers from the electrodes. Here they report the effect of this coating on the dielectric strength of high-density polyethylene. The polyethylene used is additive-free blown film with a density of 0.950 g/cm/sup 3/ and a melt flow rate of 0.9 g/10 min. The plasma-polymer coated sample studied is shown to have a higher breakdown strength than one without plasma-coating. The plasma-polymerized ethylene is amorphous, with many localized states in the forbidden band. These states act as trapping sites for electrons injected from the cathode. The trapped electrons, in turn, suppress the succeeding carrier injection from the cathode. The trapping centers seem to have an injection-suppressing effect even for the application of short-duration voltages such as impulse voltages. It is concluded that the suppression of electron injection by the coating brings about an increase in breakdown voltage.<>
{"title":"Effect of plasma polymer coating on the dielectric strength of polyethylene","authors":"T. Nakano, T. Kihira, Y. Ohki","doi":"10.1109/ICSD.1989.69223","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69223","url":null,"abstract":"The authors have shown previously (1987) that a thin layer of plasma-polymerized ethylene deposited on the surface of high-density polyethylene suppresses the injection of carriers from the electrodes. Here they report the effect of this coating on the dielectric strength of high-density polyethylene. The polyethylene used is additive-free blown film with a density of 0.950 g/cm/sup 3/ and a melt flow rate of 0.9 g/10 min. The plasma-polymer coated sample studied is shown to have a higher breakdown strength than one without plasma-coating. The plasma-polymerized ethylene is amorphous, with many localized states in the forbidden band. These states act as trapping sites for electrons injected from the cathode. The trapped electrons, in turn, suppress the succeeding carrier injection from the cathode. The trapping centers seem to have an injection-suppressing effect even for the application of short-duration voltages such as impulse voltages. It is concluded that the suppression of electron injection by the coating brings about an increase in breakdown voltage.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123557059","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}
A. Bulinski, S. Bamji, R. Densley, J. Crine, B. Noirhomme, B. Bernstein
The authors have undertaken a detailed Fourier transform infrared spectroscopy study of more than 250 water trees from more than twenty field-aged cables supplied by different utilities in the US and Canada. Most of these cables, removed from service after six to fifteen years, contained large water trees. The results give an ambiguous picture of the role of oxidation on water treeing. The experimental difficulties in the detection and evaluation of the amount of oxidation in water trees are discussed. The results of water tree growth tests on XLPE cable insulation preoxidized in air to the level similar to that observed in field-aged cables after many years of service show that increased oxidation does not affect the initiation of vented water trees but it does affect the water tree growth rate. This is very important as it may result in significantly reduced times to breakdown in actual cables. Results of water tree tests performed in a nitrogen atmosphere are also presented. The initiation of vented water trees was not affected by the gas atmosphere, but the trees grew twice as fast as in air.<>
{"title":"Influence of oxidation on water tree initiation and growth in XLPE cables","authors":"A. Bulinski, S. Bamji, R. Densley, J. Crine, B. Noirhomme, B. Bernstein","doi":"10.1109/ICSD.1989.69233","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69233","url":null,"abstract":"The authors have undertaken a detailed Fourier transform infrared spectroscopy study of more than 250 water trees from more than twenty field-aged cables supplied by different utilities in the US and Canada. Most of these cables, removed from service after six to fifteen years, contained large water trees. The results give an ambiguous picture of the role of oxidation on water treeing. The experimental difficulties in the detection and evaluation of the amount of oxidation in water trees are discussed. The results of water tree growth tests on XLPE cable insulation preoxidized in air to the level similar to that observed in field-aged cables after many years of service show that increased oxidation does not affect the initiation of vented water trees but it does affect the water tree growth rate. This is very important as it may result in significantly reduced times to breakdown in actual cables. Results of water tree tests performed in a nitrogen atmosphere are also presented. The initiation of vented water trees was not affected by the gas atmosphere, but the trees grew twice as fast as in air.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115200465","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}
Water-tree counting measurements, water and impurity content measurements, and AC breakdown tests were performed on several field-aged medium-voltage extruded cables. The results indicate that the water-tree density increases with the insulation contamination level, particularly for aluminium, sodium, and potassium contaminant. However, neither of these aging factors seems to be correlated with the residual dielectric strength, which, on the contrary, is clearly influenced by the water content. In fact, the results suggest that water is the major aging factor of XLPE (cross-linked polyethylene) cables.<>
{"title":"Effect of water on the performance of XLPE insulation","authors":"S. Pélissou","doi":"10.1109/ICSD.1989.69235","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69235","url":null,"abstract":"Water-tree counting measurements, water and impurity content measurements, and AC breakdown tests were performed on several field-aged medium-voltage extruded cables. The results indicate that the water-tree density increases with the insulation contamination level, particularly for aluminium, sodium, and potassium contaminant. However, neither of these aging factors seems to be correlated with the residual dielectric strength, which, on the contrary, is clearly influenced by the water content. In fact, the results suggest that water is the major aging factor of XLPE (cross-linked polyethylene) cables.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114376772","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}
The temperature gradient of crystal lattice spacings and X-ray reflection intensities has been found to change discontinuously at 150 degrees C for cellulose I (Cell I) and at 100 degrees C for cellulose II (Cell II). These breaks reflect a transition related to the onset of the backbone motion in the crystalline phase. The authors have attempted to confirm this conclusion by measuring the DC conductivity from room temperature to about 230 degrees C for Cell I and Cell II both parallel and perpendicular to the fiber direction. The conduction mechanism is discussed in relation to the absorption current of Cell I under a DC field in the temperature range from 140 degrees C to 230 degrees C, where the DC conductivity becomes relatively high. The results indicate that the increase of carrier mobility above the transition temperature of crystallites arises from the backbone motion in the disordered crystalline phase (mesophase) and that proton transfer is an elementary mechanism for both absorption and steady currents.<>
{"title":"Electrical conduction of cellulose under DC field","authors":"M. Takahashi, H. Takenaka, Y. Wada","doi":"10.1109/ICSD.1989.69185","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69185","url":null,"abstract":"The temperature gradient of crystal lattice spacings and X-ray reflection intensities has been found to change discontinuously at 150 degrees C for cellulose I (Cell I) and at 100 degrees C for cellulose II (Cell II). These breaks reflect a transition related to the onset of the backbone motion in the crystalline phase. The authors have attempted to confirm this conclusion by measuring the DC conductivity from room temperature to about 230 degrees C for Cell I and Cell II both parallel and perpendicular to the fiber direction. The conduction mechanism is discussed in relation to the absorption current of Cell I under a DC field in the temperature range from 140 degrees C to 230 degrees C, where the DC conductivity becomes relatively high. The results indicate that the increase of carrier mobility above the transition temperature of crystallites arises from the backbone motion in the disordered crystalline phase (mesophase) and that proton transfer is an elementary mechanism for both absorption and steady currents.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114547145","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}
Dielectric spectroscopy was used to investigate conduction processes in zinc oxide varistors. Initial results on the complex dielectric permittivity with and without an applied DC bias are presented. Some novel features in the dielectric properties of ZnO varistors that deserve further study were revealed. The differences between the measured epsilon (f) of thick and thin samples are little understood at present. A possibility is that uninterrupted channels of intergranular Bi-rich phases are more likely to be present in thin samples, increasing the importance of this conduction path.<>
{"title":"Dielectric properties of zinc oxide based varistors","authors":"K. Brantervik, G. Niklasson","doi":"10.1109/ICSD.1989.69210","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69210","url":null,"abstract":"Dielectric spectroscopy was used to investigate conduction processes in zinc oxide varistors. Initial results on the complex dielectric permittivity with and without an applied DC bias are presented. Some novel features in the dielectric properties of ZnO varistors that deserve further study were revealed. The differences between the measured epsilon (f) of thick and thin samples are little understood at present. A possibility is that uninterrupted channels of intergranular Bi-rich phases are more likely to be present in thin samples, increasing the importance of this conduction path.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127565818","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}
The author reviews the various experimental techniques used to measure charge distributions in dielectrics. He then focuses on the pressure wave propagation method, discussing the principle of the method and techniques of pressure-wave generation. Examples of applications of the pressure-wave propagation method can be found in the fields of high-voltage insulation, piezoelectricity, irradiated materials, and space charge effects are given.<>
{"title":"Direct determination of space charge distributions in dielectrics: the pressure wave propagation method","authors":"J. Lewiner","doi":"10.1109/ICSD.1989.69257","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69257","url":null,"abstract":"The author reviews the various experimental techniques used to measure charge distributions in dielectrics. He then focuses on the pressure wave propagation method, discussing the principle of the method and techniques of pressure-wave generation. Examples of applications of the pressure-wave propagation method can be found in the fields of high-voltage insulation, piezoelectricity, irradiated materials, and space charge effects are given.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"58 24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127869156","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}
Studies of the influence of strongly bound water on electrical properties of plasma-deposited organosilicon films indicate that two types of hopping centers exist in the films. The first type can be destroyed by water molecules and the second is stable. In SiNSi films both types of hopping centers exist, but in SiOSi films only the second type exists. However, in both SiNSi and SiOSi films, water molecules activate initially inactive intrinsic acceptor centers. As a result the electrical conductivity increases in organosilicon films in the presence of absorbed water.<>
{"title":"Influence of absorbed water on electronic transport in organosilicon plasma polymers","authors":"J. Tyczkowski, J. Sielski","doi":"10.1109/ICSD.1989.69184","DOIUrl":"https://doi.org/10.1109/ICSD.1989.69184","url":null,"abstract":"Studies of the influence of strongly bound water on electrical properties of plasma-deposited organosilicon films indicate that two types of hopping centers exist in the films. The first type can be destroyed by water molecules and the second is stable. In SiNSi films both types of hopping centers exist, but in SiOSi films only the second type exists. However, in both SiNSi and SiOSi films, water molecules activate initially inactive intrinsic acceptor centers. As a result the electrical conductivity increases in organosilicon films in the presence of absorbed water.<<ETX>>","PeriodicalId":184126,"journal":{"name":"Proceedings of the 3rd International Conference on Conduction and Breakdown in Solid Dielectrics","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126661926","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：