Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982最新文献

{"title":"Effects of chemical impurities on prebreakdown events in toluene","authors":"G. FitzPatrick, E. Forster, E. Kelley, R. Hebner","doi":"10.1109/CEIDP.1982.7726566","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726566","url":null,"abstract":"Effects of chemical impurities on the breakdown process in toluene have been investigated under non-uniform field conditions using a high-speed image converter camera. The resistivity of the four samples investigated ranged from 109 to 1013 Ω cm. It was noted that when the cathode was a point, streamer growth rate increased slightly with decreasing resistivity. When the needle was an anode, streamer growth rate was not measurably affected by changes in resistivity or applied voltage, requiring 1.6 ± 0.3 μs to cross the 3 mm gap. Independent of the polarity of the needle, the last step in the traverse leading to breakdown of the gap occurred at speeds greater than 1 × 106 cm/s. In purified toluene, more than 200 kV could be applied to a 3 mm gap without breakdown. With the needle as a cathode, impurities facilitated the generation of secondary streamers which appeared to grow from the primary bush-like streamers. With decreasing resistivity, the branching of these streamers seemed to increase.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"9 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115728438","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}

{"title":"Townsend breakdown criterion in electronegative gases","authors":"M. Salama, A. Nosseir","doi":"10.1109/CEIDP.1982.7726559","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726559","url":null,"abstract":"A simple mathematical formula suitable for calculating the breakdown voltage of electronegative gases under uniform and quasi-uniform fields, has been developed in this paper. The values of Townsend ionization coefficients and attachment coefficient taken from the literature [l]have been used to determine the constants of this formula. Employing the concept of the shape factor, the formula is found to be valid for practical gap configurations of quasi-uniform field distribution, such as two spheres and co-axial cylinder gaps. Breakdown voltages for different gas pressure can also be predicated.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116924873","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}

{"title":"Piezoelectric polymers in non-destructive dielectric evaluation","authors":"K. Doughty, D. Das-Gupta, R. Shuford, Y. Hinton","doi":"10.1109/CEIDP.1982.7726543","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726543","url":null,"abstract":"Thin films of polyvinylidene fluoride (PVF2) can be rendered piezoelectric by corona poling at suitably high electric fields. The mechanical strength of the film, together with its flexibility and reasonably flat piezo-electric response over a wide bandwidth, makes it useful for the detection of acoustic emission signals which may originate from deformation and flow propagation in a material under dynamic or static loading. Present work reports an evaluation of the piezoelectric response and the electro-mechanical coupling coefficient k332 in corona-poled PVF2 over a frequency range of 10 Hz to 1 MHz.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"24 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120866469","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}

{"title":"Influence of a few parameters on thermostimulated depolarization currents flowing on a fused silica surface","authors":"B. Despax, P. Peres, C. Huraux","doi":"10.1109/CEIDP.1982.7726530","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726530","url":null,"abstract":"Interdigitated comb-shaped electrodes printed on an insulating solid surface provide a tool very suitable to put in evidence the electrical properties variations occuring when this surface interacts with the gaseous atmosphere in which it is placed. These changes in dielectric behaviour can be observed with this electrode pattern either measuring electrical conductivity /1/, or recording Surface Thermostimulated Depolarization Current (STDC) spectra /2/. We will briefly recall this latter method procedure. After a conditioning treatment which will be defined later, a polarization voltage Vp was applied to the electrodes during a time tp at at temperature Tp. Afterwards, the sample was cooled to −150°C then polarization voltage was cut off and the electrodes were linked together across an electrometer connected to a graph plotter. Depolarization current Id was recorded while the sample temperature was increased slowly at a constant rate. We shall report in this paper how STDC spectra recorded on fused silica specimens can be influenced by a few parameters.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125311541","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}

{"title":"Elementary processes in the development of the electrical breakdown of liquids (a review)","authors":"W. Schmidt","doi":"10.1109/CEIDP.1982.7726550","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726550","url":null,"abstract":"The investigation of electric breakdown phenomena in liquids has been a continuing effort since the early years of this century. An immense amount of information (both published in journals and books and unpublished, resting in the archives of industry or research laboratories) has been accumulated — but our understanding of the phenomenon remains rudimentary when compared to our state of knowledge with respect to the breakdown of gases or solids. While their theoretical concepts have been developed which incorporate the physical elementary processes of charge carrier generation and transport (e.g. for gases the Towns-end and streamer theory, and for solids the Landau-Zener theory and the electrothermal breakdown theory) a similar high level status of theoretical penetration is missing for liquids. The main reasons for this poor performance are the following: a) the understanding of the physical properties of the liquid state is less well developed as compared to gases and solids; b) the experimental information on liquid breakdown accumulated in the literature to a large extent does not lend itself suitable for generalization or as a starting point for theoretical considerations. Hundreds of papers and reports are, for instance, available on transformer oil which actually is an illdefined heterogeneous system comprised of different liquids, solid materials, and gases. From the measurements point of view many papers lack sufficiently well controlled experimental conditions so that the data cannot be used as points of reference for theories. c) the number of liquids of possible interest to electrical engineering applications is in the range of ten to hundred and these liquids exhibit a wide spectrum of physical and chemical properties. Time and space preclude an extensive treatment of all the various aspects of the breakdown phenomenon. Some topics omitted here may be found in other talks of this symposium or in some recent reviews of this field [1-3]. In this review we shall limit ourselves mainly to pure non-polar liquids and we shall consider only two extreme cases of voltage application: step-impulse voltages and voltages which vary slowly in time (DC, line frequency AC).","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129535235","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}

{"title":"Optical and scanning electron microscope observations of substrate effects on the crystallization of polyvinylidene fluoride from solution","authors":"V. Gelfandbein, M. Perlman","doi":"10.1109/CEIDP.1982.7726528","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726528","url":null,"abstract":"In has been more than a decade since it was first reported that drawn polyvinylidene fluoride (PVDF) film showed large piezo- and pyro-electric effects. This polymer has been the subject of intense investigation, partly because of its commercial application to transducers and infra red (IR) sensors. PVDF can exist in at least five distinct polymorphs, three of which are electrically active [1], There are reasons to believe that polymorphism is more the rule than the exception in macromolecules. Recently, we showed that crystallization of PVDF from solution onto different substrates gave rise to different polymorphs [2]. The structure of cast PVDF varied between α, β and γ forms, or mixtures of them, depending on the nature of the substrate. X-ray diffraction scans of PVDF cast on glass or silicon showed a peak located at 2θ ≃ 20.5°, which we attributed to a possible precursor of the β form.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124319395","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}

{"title":"Lightning impulse breakdown of ROD-plane gaps in CO2 and CO2/CCl2F2 mixtures","authors":"T. V. B. Rajendran, C. Lakshminarasimha, M. Naidu","doi":"10.1109/CEIDP.1982.7726558","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726558","url":null,"abstract":"Binary and ternary mixtures of electronegative gases are presently being experimented as possible insulants in high voltage power apparatus and systems. In recent times, several investigations have been carried out to determine the breakdown voltages and processes leading to breakdown in such gas mixtures [1-4]. Studies were undertaken at our laboratory to determine the breakdown characteristics of such mixtures using impulse and switching surge voltages, in nonuniform fields. In this paper, some of the interesting results obtained with lightning impulse voltages in CO2 and CO2/CCl2F2 mixtures are reported.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133666094","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}

{"title":"Dielectric properties and ESCA study of plasma polymerized ethylene","authors":"Y. Ohki, N. Hozumi, Toshiyuki Takao, Yasuhiro Kasama","doi":"10.1109/CEIDP.1982.7726526","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726526","url":null,"abstract":"Plasma polymerized films have good insulation properties. However, there are many residual free radicals in the film. These free radicals may be very sensitive to the atmosphere where the sample is kept after polymerization. In this paper, dielectric properties of tanδ and conduction are discussed in reference to the measurement of Electron Spin Resonance (ESR) and Electron Spectroscopy for Chemical Analysis (ESCA).","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121977558","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}

{"title":"Partial discharges induced by small floating potential metallic elements","authors":"C. Cooke","doi":"10.1109/CEIDP.1982.7726541","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726541","url":null,"abstract":"Partial discharge (PD) measurements are commonly employed in non-destructive testing of dielectrics and systems. Often voids, interface adhesion problems, or electrode surface irregularities can be detected. Another type of defect is the small metallic element which is not connected to an electrode but can also cause partial discharge. The partial discharges from such elements at floating potential are associated with the local field intensifications which they cause. The geometry of a metallic element, its orientation with respect to the applied fields, and the net charge accumulated by the element have been found to influence both the inception and steady-state partial discharges. A model for PD behavior based on charge transport to and from the element is developed to describe the voltage and time dependence. The results are compared to time-synchronized pulse height-analyzed measurements.","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128463634","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}

{"title":"Critical factors in polypropylene film used for pulsed power capacitors","authors":"I. Galperin, W. White","doi":"10.1109/CEIDP.1982.7726580","DOIUrl":"https://doi.org/10.1109/CEIDP.1982.7726580","url":null,"abstract":"Isotactic polypropylene is a polyolefin with a helical structure involving at least 50 percent crystallinity [1]. This spiral structure results in a crystallized polymer of lower density than polyethylene. Polypropylene is a stereoregular polymer which is almost 100 percent isotactic in capacitor film applications [2]. Biaxial orientation of polypropylene film overcomes the tendency of polypropylene to fibrilate when oriented and is a major reason for use of such films in capacitors [3].","PeriodicalId":301436,"journal":{"name":"Conference on Electrical Insulation & Dielectric Phenomena - Annual Report 1982","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128502182","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}