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Properties and Applications of Dielectric Materials, 1988. Proceedings., Second International Conference on Properties and Applications of

Date 12-16 Sept. 1988

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  • Proceedings. Second International Conference on Properties and Applications of Dielectric Materials (Cat. No.88CH2587-4)

    Publication Year: 1988
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    Freely Available from IEEE
  • Long time range breakdown in polymeric insulating films subjected to step voltage

    Publication Year: 1988, Page(s):355 - 358 vol.1
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (343 KB)

    The breakdown time lags for five kinds of polymeric insulating films subjected to a step voltage were measured in the minute range at room temperature. The time-lag distributions were classified into two types, exponential and normal distributions. Low-density polyethylene (LDPE), polystyrene (PS), and polypropylene (PP) belong to the exponential distribution class while polycarbonate (PC) and eth... View full abstract»

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  • Selection of insulation level of HVAC power lines operating in high altitude polluted area

    Publication Year: 1988, Page(s):268 - 271 vol.1
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    A description is given of a method for choosing the insulation level of power lines operating in a high-altitude polluted area on the basis of an artificial pollution test. The test was carried out in a pressure chamber in which the air pressure could be controlled. The chamber was used to simulate air pressure for different altitudes. It was found that under the same degree of pollution the withs... View full abstract»

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  • Study of the dielectric properties of oil impregnated PPLP for UHV cable insulation

    Publication Year: 1988, Page(s):682 - 685 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB)

    The dielectric properties and breakdown strength of oil-impregnated polypropylene laminated paper (PPLP), the compatibility between oil and PPLP, and accelerated life test on a miniature cable model are examined. Ways to improve the characteristics of PPLP have been suggested. Experiments show that the properties of impregnated PPLP with dodecyl benzene are superior to those of kraft paper, and th... View full abstract»

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  • Evaluation of analytical techniques for the characterization of dielectric materials

    Publication Year: 1988, Page(s):9 - 12 vol.1
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (244 KB)

    A critical review of various analytical techniques tentatively used to characterize cable is presented. It is shown that cable morphology can be simply evaluated by density and differential scanning calorimetry measurements, and oxidation is best evaluated by Fourier transform infrared spectroscopy. Elemental contamination is well evaluated by neutron activation analysis and particle-induced X-ray... View full abstract»

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  • Measurement of dynamic potential distribution during the propagation of a local arc along a polluted surface

    Publication Year: 1988, Page(s):264 - 267 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (216 KB)

    A novel method for measuring the dynamic potential distribution during the propagation of a local arc along a polluted surface is described. In order to study the role of electric stress during the pollution flashover process, a flat polluted glass plate model has been designed. Measuring electrodes made with a strip of aluminum foil were stuck to the bottom of the plate, opposite the side on whic... View full abstract»

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  • EPR study of the ageing process in epoxy resin

    Publication Year: 1988, Page(s):315 - 319 vol.1
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    The authors describe a study in which epoxy resin specimens were stressed electrically and/or thermally and the evolution of the EPR spectra was measured. The electrical stresses used caused significant internal discharges in some samples prior to failure. Furthermore, electrical pulses at the terminals can be expected in concert with the channel development observed. For this reason, discharge de... View full abstract»

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  • Space charge in extruded insulation under DC divergent field

    Publication Year: 1988, Page(s):678 - 681 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    Curves of thermally stimulated current (TSC) from XLPE (cross-linked polyethylene) specimens were obtained and in turn used to determine the trap depths of the specimens with charge transfer complexes (CTC), antistatic agents, and polypropylene and polystyrene additives. The relation between space charge in dielectrics and charge-injection time was established. By studying tree growth in various s... View full abstract»

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  • Progress of the research on external insulations in China

    Publication Year: 1988, Page(s):1 - 8 vol.1
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (572 KB)

    A series of research projects has been launched to tackle the problem of outdoor insulation performance under various atmospheric conditions. Since a large portion of China's power transmission projects is located in the high-altitude plateau area with different weather conditions, special attention is paid to the problem of insulation in conditions of reduced air density and high humidity. The te... View full abstract»

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  • DC flashover characteristics of the contaminated insulators under low atmospheric pressure

    Publication Year: 1988, Page(s):260 - 263 vol.1
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (188 KB)

    A simple test arrangement for the investigation of DC pollution flashover characteristics of insulators under low pressure and a DC power source meeting the needs of pollution testing are discussed. The DC pollution flashover performances of two types of insulators with various surface salt deposit densities were investigated under pressures of 48-101 kPa. The pollution discharge phenomena and the... View full abstract»

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  • Regularity of breakdown of solid dielectrics after moisture absorption

    Publication Year: 1988, Page(s):412 - 415 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    The authors examine the usually encountered problems of environmental compatibility experiments on the breakdown of solid dielectrics after moisture absorption. These include: (1) the excessive reduction of dielectric strength and (2) an abnormal phenomenon in the case of which increases in moisture absorption cause the dielectric strength of the solid dielectric to increase at the start and then ... View full abstract»

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  • Long term electrical and thermal behavior of transformer oil/paper insulation under simulated service conditions

    Publication Year: 1988, Page(s):311 - 314 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (312 KB)

    A bench-top test method was designed to establish the long-term electrical and thermal behavior under simulated service conditions in order to allow the efficient screening of candidate oils at a reduced final cost when compared to model-type tests. The method is based on the use of small test models aged at stresses slightly above normal operating values with temperature and voltage as the accele... View full abstract»

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  • Polypropylene film dielectric used in power capacitors

    Publication Year: 1988, Page(s):674 - 677 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (200 KB)

    The authors outline the application of electric polypropylene film (PPF) to power capacitors in China and discuss in a non-chloride-impregnated PPF dielectric capacitor with folded aluminum-foil electrodes improvement of the ability to withstand harmonics, the reliability, the partial discharge property, and the loss tangent of the dielectric, all of which were assessed on the basis of the researc... View full abstract»

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  • The influence of gases in solution in the polymer on the propagation of water trees

    Publication Year: 1988, Page(s):726 - 727 vol.2
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (156 KB)

    The growth of water trees was measured using the water needle test in laboratory polyethylene specimens. The effect of deaerating the specimens and annealing them under different gaseous atmospheres is investigated. These factors were found to be secondary compared with the role played by annealing itself. The gas in contact with the material during the growth of water trees influenced not the ini... View full abstract»

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  • Some observations on artificial cavities in a cross-linked polyethylene

    Publication Year: 1988, Page(s):430 - 433 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (196 KB)

    An experimental study of artificial cavities in cross-linked polyethylene (XLPE) was conducted, and results are compared with those for other materials. Discharge evolution vs. time in XLPE cavities (both sealed and open) is reported. An examination of discharge characteristics vs. time shows an abrupt decrease of discharge frequency during the first 30 min; their number reaches a steady state but... View full abstract»

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  • The compositions and properties of electric porcelain materials in China

    Publication Year: 1988, Page(s):256 - 259 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    The composition, main properties, and scope of application of the two categories of electric porcelain materials, namely silicious porcelain and aluminous porcelain, and their corresponding glaze are presented. The characteristics of both materials conform to IEC 672-3 (1984) group C-100 on alkali alumina silicate material for electric power use. In order to utilize the rich bauxite resources in C... View full abstract»

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  • Investigation of breakdown values and charge storage properties of PVDF

    Publication Year: 1988, Page(s):408 - 411 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (184 KB)

    The breakdown values and charge storage properties of thin-film PVDF (polyvinylidene fluoride) were investigated with a view to the possible manufacture of small volume, high-energy-density capacitors for use in medical implant devices. The dielectric breakdown fields of 3.5-μm- and 6-μm-thick films of PVDF have been measured using a field which increases linearly with time. The rate of rise... View full abstract»

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  • Computer aided measurement of dielectric properties of saline solutions using a six-port reflectometer

    Publication Year: 1988, Page(s):189 - 192 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB)

    An open-ended coaxial line is used as a nondestructive broadband impedance sensor to measure the permittivity of an NaCl aqueous solution as a function of concentration, temperature, and wave frequency, using a six-port reflectometer (SPR). Permittivity measurements obtained from 2.5 to 4 GHz with the SPR are compared to results previously published. It is found that the SPR can provide broadband ... View full abstract»

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  • Computer-aided design of insulators

    Publication Year: 1988, Page(s):307 - 310 vol.1
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    A new method is described which is based on the computer-aided design concept for optimizing insulator contours according to a given field distribution along their surfaces. The method uses field calculation by means of surface charge simulation and some iteration procedures in order to get optimized contours. The influence of insulator materials like PE or PVC on the calculated contours is presen... View full abstract»

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  • An application of polyacrylonitrile (PAN) oxygen catalytic fibre [motor corona protection]

    Publication Year: 1988, Page(s):671 - 673 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (108 KB)

    In the process of making `c' fiber from PAN, there is an intermediate product called oxygen catalytic fiber, which features different semiconductor resistivities with respect to different heat treatment temperatures. This kind of fiber or fiber braid has good electric characteristics, mechanical strength, temperature stability, and ease of processing. It has been successfully used in high... View full abstract»

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  • Short term effects of DC and AC corona on the surface electrical properties of polymer films

    Publication Year: 1988, Page(s):606 - 609 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (204 KB)

    The effects of DC and AC corona on loss tangent measurements in four thin foil polymer samples were investigated. The materials investigated were 25-μm polyimide (PI), 75-μm low-density polyethylene, 12-μm polyester, and 25-μm polytetrafluorethylene. Surface conductivity measurements of PI samples exposed to negative corona were also made, as were measurements of temperature effects on... View full abstract»

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  • Transformerboard insulation under HVDC

    Publication Year: 1988, Page(s):721 - 725 vol.2
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    The authors use simplified model schemes for studying the static and dynamic processes of ion movement and charge carrier deposition in the board oil system. An approximate sample calculation has been made. The benefits of a novel Transformerboard material with a lower resistivity are shown. Computer field plots of the voltage distribution at AC and DC in a typical composed transformer insulation ... View full abstract»

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  • Development and tests of extruded polyethylene insulated superconducting cable

    Publication Year: 1988, Page(s):426 - 429 vol.2
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB)

    A superconducting power cable which has a similar structure to the conventional extruded polyethylene cable is proposed. The rated voltage and current are 20 kV and 2 kA, respectively. The design utilizes the excellent electrical properties of polyethylene at cryogenic temperatures and separate helium coolant from the electrical insulation. The outer superconductor layers for magnetic shielding ar... View full abstract»

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  • The study of humidity on flashover voltage characteristics for positive SI

    Publication Year: 1988, Page(s):253 - 255 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB)

    A description is given of the flashover characteristics (U50%) of seven typical objects over a range of atmospheric conditions. It was found that the influence of humidity on flashover voltage is different at different altitudes, when compared with respect to the IEC humidity correction factor K and China standard GB311-83. The corrected value in the geographic region studied is higher th... View full abstract»

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  • Composite longrod-the solution of future line insulation in China

    Publication Year: 1988, Page(s):237 - 240 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (276 KB)

    A composite long rod insulator produced in the authors' laboratory is discussed. The insulator is made of porcelain and silicone rubber. Test results on the electrical and mechanical properties are reported. The insulator has many advantages, such as light weight, ease of manufacture, high mechanical strength, very good antipollution performance, no risk of internal puncture, and reduced need for ... View full abstract»

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