Pub Date : 2011-10-01DOI: 10.1109/CEIDP.2011.6232652
O. M. Hamid, S. Jayaram
The smart grid with state of the art technology is expected to facilitate ease of dispersed generators (DGs) connected to the distribution network. However, the fast switching power converter based interface of dispersed DGs to the distribution network is a potential source of harmonic injection; hence a considerable distortion in the voltage waveforms. With increased DG penetration, such harmonics may become a potential source of high frequency; high dv/dt stresses on the insulation system of vital power system. Additional stresses implies faster degradation rate of insulation system. Understanding such harmonic based stresses will help in designing an improved insulation system to withstand high stresses created by the switching devices. The paper presents the electric field simulation results, of a transformer model winding, which is a representative of a typical distribution class transformer, under various distorted voltage waveforms.
{"title":"Distribution class transformer insulation evaluation under distorted voltage waveforms","authors":"O. M. Hamid, S. Jayaram","doi":"10.1109/CEIDP.2011.6232652","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232652","url":null,"abstract":"The smart grid with state of the art technology is expected to facilitate ease of dispersed generators (DGs) connected to the distribution network. However, the fast switching power converter based interface of dispersed DGs to the distribution network is a potential source of harmonic injection; hence a considerable distortion in the voltage waveforms. With increased DG penetration, such harmonics may become a potential source of high frequency; high dv/dt stresses on the insulation system of vital power system. Additional stresses implies faster degradation rate of insulation system. Understanding such harmonic based stresses will help in designing an improved insulation system to withstand high stresses created by the switching devices. The paper presents the electric field simulation results, of a transformer model winding, which is a representative of a typical distribution class transformer, under various distorted voltage waveforms.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"37 1","pages":"284-287"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84779573","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 : 2011-10-01DOI: 10.1109/CEIDP.2011.6232777
A. Huzayyin, S. Boggs, R. Ramprasad
Charge injection at a polyethylene/platinum interface is studied through use of density functional theory (DFT). Various crystal orientations at the interface hetero-structure are considered. The computed minimum barriers for electrons and hole injection at an impurity free interface are 3.15 and 2.62 eV, respectively. The work demonstrates that chemical impurities play an important role in the injection process. Impurity states, such as those of carbonyl, can reduce the effective barriers to charge injection to about 1.0 eV.
{"title":"Quantum mechanical study of charge injection at the interface of polyethylene and platinum","authors":"A. Huzayyin, S. Boggs, R. Ramprasad","doi":"10.1109/CEIDP.2011.6232777","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232777","url":null,"abstract":"Charge injection at a polyethylene/platinum interface is studied through use of density functional theory (DFT). Various crystal orientations at the interface hetero-structure are considered. The computed minimum barriers for electrons and hole injection at an impurity free interface are 3.15 and 2.62 eV, respectively. The work demonstrates that chemical impurities play an important role in the injection process. Impurity states, such as those of carbonyl, can reduce the effective barriers to charge injection to about 1.0 eV.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"63 1","pages":"800-803"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91092127","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 : 2011-10-01DOI: 10.1109/CEIDP.2011.6232650
R. Haller, J. Pihera, Petr Mraz, Stefan Kornhuber, M. Boltze
The PD behaviour of so called basic test arrangements as for corona discharge or other discharge sources seems to be well known from the physical side of view. On the other hand the measurement results and, in the same manner, their identification and interpretation can be different, because this is depending on the measurement or evaluation conditions. Therefore some typical corona basic arrangements representing corona needle-plane, needle-plane with insulating material and needle-sphere are investigated. The measurements are carried out under different measurement conditions especially the selected frequency range of the measuring system. For some effects the reproducibly, the voltage dependence and the changes over time of the PD behaviour are investigated. These results were evaluated using the applied and the updated version of IEC 60270. Furthermore the IEC 60270 and additional publications provide a lot of possible of the post evaluation of the measured PD signals. In this paper the most and most recognized values are compared at the well defined laboratory set ups as defined. Additional these results are compared with the results of the Pulse-Sequence-Analyzing method. The presented results show surprisingly characteristic shapes of the PD pattern, which allow the better classification of the types of PD sources and their identification respectively.
{"title":"PD behaviour of basic test arrangements under different measurement and evaluation conditions","authors":"R. Haller, J. Pihera, Petr Mraz, Stefan Kornhuber, M. Boltze","doi":"10.1109/CEIDP.2011.6232650","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232650","url":null,"abstract":"The PD behaviour of so called basic test arrangements as for corona discharge or other discharge sources seems to be well known from the physical side of view. On the other hand the measurement results and, in the same manner, their identification and interpretation can be different, because this is depending on the measurement or evaluation conditions. Therefore some typical corona basic arrangements representing corona needle-plane, needle-plane with insulating material and needle-sphere are investigated. The measurements are carried out under different measurement conditions especially the selected frequency range of the measuring system. For some effects the reproducibly, the voltage dependence and the changes over time of the PD behaviour are investigated. These results were evaluated using the applied and the updated version of IEC 60270. Furthermore the IEC 60270 and additional publications provide a lot of possible of the post evaluation of the measured PD signals. In this paper the most and most recognized values are compared at the well defined laboratory set ups as defined. Additional these results are compared with the results of the Pulse-Sequence-Analyzing method. The presented results show surprisingly characteristic shapes of the PD pattern, which allow the better classification of the types of PD sources and their identification respectively.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"1 1","pages":"275-279"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80714658","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 : 2011-10-01DOI: 10.1109/CEIDP.2011.6232732
S. J. Han, J. Kjellqvist
In modern power cable design, crosslinked polyethylene (XLPE) is a major choice of insulation compound for distribution and transmission cables. Crosslinking will lead to enhance both dimensional stability at elevated temperatures and physical integrity under high electrical stress of the compounds for HV and EHV power cables. Thermal decomposition of organic peroxides from cable compounds in cable fabrication process will retain some of decomposition byproducts within the compounds, which increase dielectric loss and generate voids as cable defects. The productivity for the high quality power cable manufacturing depends on optimization of production rates from extrusion, thermal treatments for crosslinking and cooling, and degassing. In this study, it is investigated about distribution of various types of decomposition byproducts levels in XLPE insulation in high voltage cables under the incomplete crosslinking condition from the continuous vulcanization (CV) process. It is correlated for mechanical and crosslinking properties of the insulation. This can help to design practical byproducts degassing procedure for high quality power cables.
{"title":"Evaluation of organic peroxide decomposition byproducts from incompletely crosslinked high voltage power cables","authors":"S. J. Han, J. Kjellqvist","doi":"10.1109/CEIDP.2011.6232732","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232732","url":null,"abstract":"In modern power cable design, crosslinked polyethylene (XLPE) is a major choice of insulation compound for distribution and transmission cables. Crosslinking will lead to enhance both dimensional stability at elevated temperatures and physical integrity under high electrical stress of the compounds for HV and EHV power cables. Thermal decomposition of organic peroxides from cable compounds in cable fabrication process will retain some of decomposition byproducts within the compounds, which increase dielectric loss and generate voids as cable defects. The productivity for the high quality power cable manufacturing depends on optimization of production rates from extrusion, thermal treatments for crosslinking and cooling, and degassing. In this study, it is investigated about distribution of various types of decomposition byproducts levels in XLPE insulation in high voltage cables under the incomplete crosslinking condition from the continuous vulcanization (CV) process. It is correlated for mechanical and crosslinking properties of the insulation. This can help to design practical byproducts degassing procedure for high quality power cables.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"100 1","pages":"615-619"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79500392","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 : 2011-10-01DOI: 10.1109/CEIDP.2011.6232755
Feipeng Wang, A. Lack, Zailai Xie, P. Frubing, W. Wirges, R. Gerhard
In this paper, ferroelectric poly(vinylidene fluoride) (PVDF) films with a thickness of about 430 nm were obtained by spin coating from a solution that contained a small portion of the ionic liquid 1-ethyl-3-methylimidazolium nitrate ([EMIM][NO3]). Before the experiments, the PVDF films were dried and thermally annealed. The sub-micrometer films on substrates show clear ferroelectric hysteresis behavior. A remanent polarization of about 60 mC/m2 was detected by means of two independent methods: Non-linear current-voltage characteristics and time-dependent current response after application of voltage steps. The coercive field decreases from 190 to 165 MV/m when the width of triangular bipolar/unipolar electric-field cycles increases from 3 to 300 ms. Quasi-static pyroelectricity increases from 14 to 18 μC/(m2 K) between -20 and +40 °C. X-ray diffraction prove that the ionic liquid enhances the crystallinity. The dipolar interaction between anions of the ionic liquid and CH2 groups in the PVDF chain during spin coating is considered to facilitate the formation of the β phase.
{"title":"Ionic liquids induce crystalline β phase and ferroelectric polarization in sub-micrometer films of poly(vinylidene fluoride) (PVDF)","authors":"Feipeng Wang, A. Lack, Zailai Xie, P. Frubing, W. Wirges, R. Gerhard","doi":"10.1109/CEIDP.2011.6232755","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232755","url":null,"abstract":"In this paper, ferroelectric poly(vinylidene fluoride) (PVDF) films with a thickness of about 430 nm were obtained by spin coating from a solution that contained a small portion of the ionic liquid 1-ethyl-3-methylimidazolium nitrate ([EMIM][NO3]). Before the experiments, the PVDF films were dried and thermally annealed. The sub-micrometer films on substrates show clear ferroelectric hysteresis behavior. A remanent polarization of about 60 mC/m2 was detected by means of two independent methods: Non-linear current-voltage characteristics and time-dependent current response after application of voltage steps. The coercive field decreases from 190 to 165 MV/m when the width of triangular bipolar/unipolar electric-field cycles increases from 3 to 300 ms. Quasi-static pyroelectricity increases from 14 to 18 μC/(m2 K) between -20 and +40 °C. X-ray diffraction prove that the ionic liquid enhances the crystallinity. The dipolar interaction between anions of the ionic liquid and CH2 groups in the PVDF chain during spin coating is considered to facilitate the formation of the β phase.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"43 1","pages":"710-713"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78931211","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 : 2011-10-01DOI: 10.1109/CEIDP.2011.6232596
S. Savin, S. Ait-Amar, D. Roger, G. Vélu
The presented paper concerns the insulation of cables providing the link between the converters and electrical machines in aircraft. It focuses on thermal aging tests performed on cables with the analysis of the capacitance variation. The tests were conducted on samples of a three-wire shielded cable, insulated with polyimide and polytetrafluoroethylene (PTFE). This study shows that the capacitance between the conductors of a cable is correlated with the aging of its electrical insulation.
{"title":"May the capacitance of power cables be an aging indicator?","authors":"S. Savin, S. Ait-Amar, D. Roger, G. Vélu","doi":"10.1109/CEIDP.2011.6232596","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232596","url":null,"abstract":"The presented paper concerns the insulation of cables providing the link between the converters and electrical machines in aircraft. It focuses on thermal aging tests performed on cables with the analysis of the capacitance variation. The tests were conducted on samples of a three-wire shielded cable, insulated with polyimide and polytetrafluoroethylene (PTFE). This study shows that the capacitance between the conductors of a cable is correlated with the aging of its electrical insulation.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"30 1","pages":"60-63"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79328949","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 : 2011-10-01DOI: 10.1109/CEIDP.2011.6232673
Jing Wang, Xidong Liang, Lin Chen, Yu Liu
Pollution flashover of the insulators threatens the safety and operation security of the power system severely. Contamination accumulation on the insulators is the precondition of the pollution flashover, while the contamination accumulation characteristics of the insulators depend on the motion characteristics of the dust particles moving around the insulators in service to a great degree. This paper researched the combined effect of the electric field, the air fluid field and the gravitational field on the dust particles' motion by means of experiments and numerical calculation. The distribution of the electric field and the electric potential around an actual insulator were calculated. The results indicate that the polarization force is very weak. Once the particles are charged, the electric field force acts and can drive the particles to move along the electric field lines. When there is a strong wind, the steady-state drag force is dominant and the particles move with the wind. These results can better explain the contamination accumulation characteristics of the insulators, and some measures are suggested to reduce the contamination accumulation.
{"title":"Combined effect of different fields on the motion characteristics of dust particles around the insulators","authors":"Jing Wang, Xidong Liang, Lin Chen, Yu Liu","doi":"10.1109/CEIDP.2011.6232673","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232673","url":null,"abstract":"Pollution flashover of the insulators threatens the safety and operation security of the power system severely. Contamination accumulation on the insulators is the precondition of the pollution flashover, while the contamination accumulation characteristics of the insulators depend on the motion characteristics of the dust particles moving around the insulators in service to a great degree. This paper researched the combined effect of the electric field, the air fluid field and the gravitational field on the dust particles' motion by means of experiments and numerical calculation. The distribution of the electric field and the electric potential around an actual insulator were calculated. The results indicate that the polarization force is very weak. Once the particles are charged, the electric field force acts and can drive the particles to move along the electric field lines. When there is a strong wind, the steady-state drag force is dominant and the particles move with the wind. These results can better explain the contamination accumulation characteristics of the insulators, and some measures are suggested to reduce the contamination accumulation.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"94 1","pages":"373-376"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77042444","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 : 2011-10-01DOI: 10.1109/CEIDP.2011.6232637
N. S. Midi, R. Ohyama
The objective of this work is to investigate lightning phenomena that occurred on sea surface. This paper is focusing on observing discharge current distribution on seawater when lightning strike on seawater surface. An imitation of sea condition that composed of an electrode system of underwater electrodes and water surface electrode was developed and lightning phenomena was imitated using spark discharge. The experiment was done using positive and negative discharge. Discharge characteristics of tap water and saline solutions with different conductivity was observed by the mean of voltage and current waveforms, discharge condition and current distribution both on water surface and underwater. Discharge characteristics during positive discharge and negative discharge show almost same characteristics. Thus, only data for positive discharge are discussed on this paper.
{"title":"Experimental studies of current distribution in stratified seawater under spark discharges","authors":"N. S. Midi, R. Ohyama","doi":"10.1109/CEIDP.2011.6232637","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232637","url":null,"abstract":"The objective of this work is to investigate lightning phenomena that occurred on sea surface. This paper is focusing on observing discharge current distribution on seawater when lightning strike on seawater surface. An imitation of sea condition that composed of an electrode system of underwater electrodes and water surface electrode was developed and lightning phenomena was imitated using spark discharge. The experiment was done using positive and negative discharge. Discharge characteristics of tap water and saline solutions with different conductivity was observed by the mean of voltage and current waveforms, discharge condition and current distribution both on water surface and underwater. Discharge characteristics during positive discharge and negative discharge show almost same characteristics. Thus, only data for positive discharge are discussed on this paper.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"37 1","pages":"223-226"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91160472","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 : 2011-10-01DOI: 10.1109/CEIDP.2011.6232661
D. Fabiani, G. Montanari, F. Palmieri
In this paper the results of space charge and conduction current measurements performed at different temperatures and electric fields on nanocomposites based on ethylene-vinyl-acetate are reported. The nanofillers are spherical TiO2 nanoparticles with a size ranging from 5 nm to 40 nm. The results show that the size of nanoparticles influences significantly electric properties of the final nanocomposite. The specimens containing the smallest nanoparticles, in fact, present better electric properties as a function of electric field and temperature. In particular, smaller space charge accumulation, lower conductivity and lower activation energy of the conduction process are detected with respect to both base material and nanocomposite with bigger nanoparticles.
{"title":"Effect of nanoparticle size on space charge behavior of EVA-TiO2 nanocomposites","authors":"D. Fabiani, G. Montanari, F. Palmieri","doi":"10.1109/CEIDP.2011.6232661","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232661","url":null,"abstract":"In this paper the results of space charge and conduction current measurements performed at different temperatures and electric fields on nanocomposites based on ethylene-vinyl-acetate are reported. The nanofillers are spherical TiO2 nanoparticles with a size ranging from 5 nm to 40 nm. The results show that the size of nanoparticles influences significantly electric properties of the final nanocomposite. The specimens containing the smallest nanoparticles, in fact, present better electric properties as a function of electric field and temperature. In particular, smaller space charge accumulation, lower conductivity and lower activation energy of the conduction process are detected with respect to both base material and nanocomposite with bigger nanoparticles.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"20 1","pages":"322-325"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73496106","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 : 2011-10-01DOI: 10.1109/CEIDP.2011.6232740
D. Fabiani, G. Montanari, F. Palmieri, V. H. Camara, A. Krivda
This paper presents results of space charge and conduction current measurements performed at three different temperatures on epoxy resin samples containing micro and nano fillers. The base material is modified by silica with different filler content (ranging from 0 to 65% in weight for the micro filler and 0 to 5% for the nano filler). The results show that space charge accumulation is largely temperature dependent for specimens containing both nano and micro fillers, i.e. space charge decreases considerably with temperature. Specimens with the nanofiller alone, on the contrary, exhibit smaller temperature dependence of space charge accumulation and conduction current (lower activation energy).
{"title":"The effect of temperature on space charge behavior of epoxy resins containing both micro and nano sized fillers","authors":"D. Fabiani, G. Montanari, F. Palmieri, V. H. Camara, A. Krivda","doi":"10.1109/CEIDP.2011.6232740","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232740","url":null,"abstract":"This paper presents results of space charge and conduction current measurements performed at three different temperatures on epoxy resin samples containing micro and nano fillers. The base material is modified by silica with different filler content (ranging from 0 to 65% in weight for the micro filler and 0 to 5% for the nano filler). The results show that space charge accumulation is largely temperature dependent for specimens containing both nano and micro fillers, i.e. space charge decreases considerably with temperature. Specimens with the nanofiller alone, on the contrary, exhibit smaller temperature dependence of space charge accumulation and conduction current (lower activation energy).","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"32 1","pages":"648-651"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90563164","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}