Pub Date : 2003-10-19DOI: 10.1109/CEIDP.2003.1254887
L. Dong, S. Lan, J.X. Yang, X. Chi
Application of plasma chemistry for gas cleaning is gaining prominence in recent years, mainly from the energy consideration point of view. Normally, the gas treatment is carried out at or above room temperature by the conventional dry-type corona reactor. However, this treatment is still inadequate for the removal of certain stable gases present in the flue gas mixture. In this work, a wet-type corona reactor is presented that can simultaneously remove NO and SO/sub 2/ at low temperatures and at atmospheric pressure. The experimental results show both removal rate of NO and SO/sub 2/ are improved in wet-type reactor than that of dry-type reactor. NO is mostly oxidized into NO/sub 2/ by the reaction with O and O/sub 3/ and NO/sub 2/ is change into HNO/sub 3/ by the reaction with OH, which is generated from H/sub 2/O. Most of the SO/sub 2/ removal is attributed to the absorption into the water film and the enhancement by the discharge plasma is small.
{"title":"Plasma chemical reaction for nitric oxide and sulfur dioxide removal in corona discharge reactor","authors":"L. Dong, S. Lan, J.X. Yang, X. Chi","doi":"10.1109/CEIDP.2003.1254887","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254887","url":null,"abstract":"Application of plasma chemistry for gas cleaning is gaining prominence in recent years, mainly from the energy consideration point of view. Normally, the gas treatment is carried out at or above room temperature by the conventional dry-type corona reactor. However, this treatment is still inadequate for the removal of certain stable gases present in the flue gas mixture. In this work, a wet-type corona reactor is presented that can simultaneously remove NO and SO/sub 2/ at low temperatures and at atmospheric pressure. The experimental results show both removal rate of NO and SO/sub 2/ are improved in wet-type reactor than that of dry-type reactor. NO is mostly oxidized into NO/sub 2/ by the reaction with O and O/sub 3/ and NO/sub 2/ is change into HNO/sub 3/ by the reaction with OH, which is generated from H/sub 2/O. Most of the SO/sub 2/ removal is attributed to the absorption into the water film and the enhancement by the discharge plasma is small.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134534729","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254852
H. Schulze, M. Lauter, W. Rehbein, K. Mecke, G. Wollenberg
The paper presents the forms of the channel formation during spark erosion. The deviations from the cylindrical discharging channels leads to completely other removal craters and therefore for changed surface roughness. The different channel types are dependent on gap conditions and pulse parameters in the first place but too dependent on the compounds in the dielectric work liquid. For the projection the technological parameter like in particular roughness, are knowledge necessary via the channel spreading and channel form, for off-line process models. The used examination methods are High Speed Framing Camera (HSFC) for the optical observation and the Confocal Lasers Scanning a Microscopy (CLSM) for the determination of the craters topologies.
{"title":"Channel spreading during the spark discharge for selected conditions and working fluids","authors":"H. Schulze, M. Lauter, W. Rehbein, K. Mecke, G. Wollenberg","doi":"10.1109/CEIDP.2003.1254852","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254852","url":null,"abstract":"The paper presents the forms of the channel formation during spark erosion. The deviations from the cylindrical discharging channels leads to completely other removal craters and therefore for changed surface roughness. The different channel types are dependent on gap conditions and pulse parameters in the first place but too dependent on the compounds in the dielectric work liquid. For the projection the technological parameter like in particular roughness, are knowledge necessary via the channel spreading and channel form, for off-line process models. The used examination methods are High Speed Framing Camera (HSFC) for the optical observation and the Confocal Lasers Scanning a Microscopy (CLSM) for the determination of the craters topologies.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130738759","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254940
R. Vogelsang, R. Brutsch, K. Frohlich
The propagation of electrical trees in bended sections of mica tapes is described. The investigations have been made because tapes in coil insulations of high voltage rotating machines cannot always be wound in a perfectly even manner. The tapes are bended at the coil edges, at places where tapes overlap or due to the taping- and manufacturing process. Possible tape bends were therefore analysed by taking micrographs of industrially made model bars. To investigate the influence on time to breakdown, treeing experiments in needle-plane specimens with barriers of bended and unbended mica tapes were made. The results show that the tree can penetrate the tape below a certain bending radius, which depends on the tape material. Tree growth through a bended tape can lead to a significantly shorter time to breakdown. The results can be used for manufacturers to specify the minimum allowable tape bending and therefore assure a higher quality of the mica insulation. The results provide also a basis for development of tape materials with a lower sensitivity to damage at regions of tape bending.
{"title":"How imperfections in mica tape barriers influence tree growth and breakdown time","authors":"R. Vogelsang, R. Brutsch, K. Frohlich","doi":"10.1109/CEIDP.2003.1254940","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254940","url":null,"abstract":"The propagation of electrical trees in bended sections of mica tapes is described. The investigations have been made because tapes in coil insulations of high voltage rotating machines cannot always be wound in a perfectly even manner. The tapes are bended at the coil edges, at places where tapes overlap or due to the taping- and manufacturing process. Possible tape bends were therefore analysed by taking micrographs of industrially made model bars. To investigate the influence on time to breakdown, treeing experiments in needle-plane specimens with barriers of bended and unbended mica tapes were made. The results show that the tree can penetrate the tape below a certain bending radius, which depends on the tape material. Tree growth through a bended tape can lead to a significantly shorter time to breakdown. The results can be used for manufacturers to specify the minimum allowable tape bending and therefore assure a higher quality of the mica insulation. The results provide also a basis for development of tape materials with a lower sensitivity to damage at regions of tape bending.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133616578","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254787
K. Wu, Y. Suzuoki, L. Dissado
An earlier model for simulation of the phase-resolved pattern of partial discharge (PD) showed that the range of PD magnitudes could be produced by a variation of discharge area. Here we present a further development of that model. When the field in the void exceeds a certain value E/sub c/, PD occurs and extends along the void surface. In the PD propagation, the fields in the discharge paths and in the perimeter segments around the PD paths are reduced little by little by gradually changing the charge distribution. And the PD is terminated when the internal field in the PD path becomes lower than a critical value E/sub in/ and the field in the perimeter segments around the PD paths becomes less than another critical value E/sub p/. The simulation results became much closer to the actual PD patterns. And the large fluctuation of PD magnitude can be simulated even without consideration of any stochastic mechanisms. This model provides an approach to explain the transition of PD pattern in the aging process in terms of the change of surface condition.
{"title":"Improved simulation model for PD pattern in voids considering effects of discharge area","authors":"K. Wu, Y. Suzuoki, L. Dissado","doi":"10.1109/CEIDP.2003.1254787","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254787","url":null,"abstract":"An earlier model for simulation of the phase-resolved pattern of partial discharge (PD) showed that the range of PD magnitudes could be produced by a variation of discharge area. Here we present a further development of that model. When the field in the void exceeds a certain value E/sub c/, PD occurs and extends along the void surface. In the PD propagation, the fields in the discharge paths and in the perimeter segments around the PD paths are reduced little by little by gradually changing the charge distribution. And the PD is terminated when the internal field in the PD path becomes lower than a critical value E/sub in/ and the field in the perimeter segments around the PD paths becomes less than another critical value E/sub p/. The simulation results became much closer to the actual PD patterns. And the large fluctuation of PD magnitude can be simulated even without consideration of any stochastic mechanisms. This model provides an approach to explain the transition of PD pattern in the aging process in terms of the change of surface condition.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131458793","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254871
A. El-Hag, S. Jayaram, E. Cherney
The paper presents two different methods to compute the current density along contaminated and wet silicone rubber insulator surface. The first method, based on field theory approach, uses the commercial software FEMLAB/spl reg/ to compute the current density. The conductivity of the contamination layer used in the calculations was extracted from the measured equivalent salt deposit density (ESDD) separately for different regions of the insulator surfaces. The second method is based on the circuit theory approach, and, the insulator surface was divided into different sections for resistance calculations to account for different contamination levels. Rankings based on the calculated current densities based on segmentation of the insulator surface for ESDD measurements match with those extracted from measured leakage currents.
{"title":"Calculation of current density along insulator surface using field and circuit theory approaches","authors":"A. El-Hag, S. Jayaram, E. Cherney","doi":"10.1109/CEIDP.2003.1254871","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254871","url":null,"abstract":"The paper presents two different methods to compute the current density along contaminated and wet silicone rubber insulator surface. The first method, based on field theory approach, uses the commercial software FEMLAB/spl reg/ to compute the current density. The conductivity of the contamination layer used in the calculations was extracted from the measured equivalent salt deposit density (ESDD) separately for different regions of the insulator surfaces. The second method is based on the circuit theory approach, and, the insulator surface was divided into different sections for resistance calculations to account for different contamination levels. Rankings based on the calculated current densities based on segmentation of the insulator surface for ESDD measurements match with those extracted from measured leakage currents.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127650560","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254841
Guanjun Zhang, Yan Sun, Wenxing Zhao, Zhang Yan
Electroluminescence (EL) phenomena reveal some important information about the electrical ageing of solid insulating materials in discharge-free condition. The EL emission from the surface of several insulating polymers with a planar electrode system was investigated under ac electric field in vacuum. It was observed at a voltage as low as /spl sim/1 kV. Its time-resolved distribution under stepped voltages, the intensity as a function of ac, positive and negative half-rectified ac voltages, the phase-resolved and spectral distributions are studied in detail. Based on the band theory of solid, a new model has been proposed to describe the EL phenomena observed, resulting from the radiative recombination of electrons and holes injected in the surface states. The experimental results and theoretical analysis also support a new approach to understanding the surface and interfacial phenomena in the field of electrical insulation.
{"title":"Surface electroluminescence phenomena of insulating polymers","authors":"Guanjun Zhang, Yan Sun, Wenxing Zhao, Zhang Yan","doi":"10.1109/CEIDP.2003.1254841","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254841","url":null,"abstract":"Electroluminescence (EL) phenomena reveal some important information about the electrical ageing of solid insulating materials in discharge-free condition. The EL emission from the surface of several insulating polymers with a planar electrode system was investigated under ac electric field in vacuum. It was observed at a voltage as low as /spl sim/1 kV. Its time-resolved distribution under stepped voltages, the intensity as a function of ac, positive and negative half-rectified ac voltages, the phase-resolved and spectral distributions are studied in detail. Based on the band theory of solid, a new model has been proposed to describe the EL phenomena observed, resulting from the radiative recombination of electrons and holes injected in the surface states. The experimental results and theoretical analysis also support a new approach to understanding the surface and interfacial phenomena in the field of electrical insulation.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124236588","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254818
É. David, R. Taghizad, L. Lamarre, D. N. Nguyen
In order to assess the quality of stator winding insulation, laboratory and field instruments measuring the charge and discharge currents flowing through rotating machine ground-wall winding insulation were developed. These instruments apply a dc voltage step during a variable charging time at various voltage levels followed by a discharge step during which the insulating dielectric is shorted to ground. The current is continuously monitored during both the charge and the discharge steps. An investigation was conducted for epoxy-mica insulation systems in laboratory as well as on complete windings in the field.
{"title":"Investigation on the low frequency dielectric response of ground-wall insulation of rotating machine windings","authors":"É. David, R. Taghizad, L. Lamarre, D. N. Nguyen","doi":"10.1109/CEIDP.2003.1254818","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254818","url":null,"abstract":"In order to assess the quality of stator winding insulation, laboratory and field instruments measuring the charge and discharge currents flowing through rotating machine ground-wall winding insulation were developed. These instruments apply a dc voltage step during a variable charging time at various voltage levels followed by a discharge step during which the insulating dielectric is shorted to ground. The current is continuously monitored during both the charge and the discharge steps. An investigation was conducted for epoxy-mica insulation systems in laboratory as well as on complete windings in the field.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124315556","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254823
M. Abou-Dakka, A. Bulinski, S. Bamji
Polarization currents obtained at a low dc field for two different brands of XLPE and EPR insulation subjected to water treeing were correlated with the corresponding time to breakdown characteristics of these materials. It is shown that although the RC time constant and the area under the polarization current curve changed consistently with the aging time for all three materials tested, the consistency and the diagnostic value of the information they provide about imminent insulation failure depends on the type of material.
{"title":"DC polarization characteristics of XLPE and EPR insulation subjected to water treeing","authors":"M. Abou-Dakka, A. Bulinski, S. Bamji","doi":"10.1109/CEIDP.2003.1254823","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254823","url":null,"abstract":"Polarization currents obtained at a low dc field for two different brands of XLPE and EPR insulation subjected to water treeing were correlated with the corresponding time to breakdown characteristics of these materials. It is shown that although the RC time constant and the area under the polarization current curve changed consistently with the aging time for all three materials tested, the consistency and the diagnostic value of the information they provide about imminent insulation failure depends on the type of material.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122166605","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254858
B. Zegnini, D. Mahi, A. Chaker
During electric flashover process its difficult to determine the real values of ions mobility, because we did not known the nature of different ions ejected forward the leader of the discharge. Using results of time to flashover measurements against applied voltage which carried out under AC with the experimental set up. In this paper the regression method is used to model accurately the relationship between flashover time and insulators parameters in order to calculate the ions mobility. Moreover the results obtained are discussed. The present study indicates that the different values of ions mobility are a good concordance between this model and those obtained in humid air and water steam.
{"title":"Ions mobility determinations on polluted HVAC insulators during electric flashover using experimental model","authors":"B. Zegnini, D. Mahi, A. Chaker","doi":"10.1109/CEIDP.2003.1254858","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254858","url":null,"abstract":"During electric flashover process its difficult to determine the real values of ions mobility, because we did not known the nature of different ions ejected forward the leader of the discharge. Using results of time to flashover measurements against applied voltage which carried out under AC with the experimental set up. In this paper the regression method is used to model accurately the relationship between flashover time and insulators parameters in order to calculate the ions mobility. Moreover the results obtained are discussed. The present study indicates that the different values of ions mobility are a good concordance between this model and those obtained in humid air and water steam.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128317831","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254895
Z. Zheng, S. A. Boggs
The effect of heat sinks placed between the ZnO elements of a surge arrester is evaluated in the context of the IEC test for thermal stability.
在IEC热稳定性测试的背景下，对放置在避雷器氧化锌元件之间的散热片的影响进行了评估。
{"title":"Heat sink effects in thermal stability tests of ZnO arresters","authors":"Z. Zheng, S. A. Boggs","doi":"10.1109/CEIDP.2003.1254895","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254895","url":null,"abstract":"The effect of heat sinks placed between the ZnO elements of a surge arrester is evaluated in the context of the IEC test for thermal stability.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128471979","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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