Two commercial crosslinkable polyethylene insulation cable granules, designed for 110 and 35 kV voltage insulation, with similar crosslinking temperature but different melting temperature, were chosen as experimental ...Two commercial crosslinkable polyethylene insulation cable granules, designed for 110 and 35 kV voltage insulation, with similar crosslinking temperature but different melting temperature, were chosen as experimental samples for examining their linear dynamic responses during cross-linking. It has been found that the gel contents of cable compounds for 110 and 35 kV insulation are almost the same after they have been cross-linked at the same temperature, pressure and time. And the sample melts show the similar dependence of the dynamic storage modulus, G; on strain. On the other hand, the dynamic temperature ramp test and the dynamic time sweep test indicate that the samples exhibit different dynamic viscoelastic responses during their crosslinking. An expression for describing their erosslinking process was proposed via probing rheokinetics of crosslinking for the two samples.展开更多
The recent developments in the photoinitiated cross-linking of polyethylene and the significant breakthrough of its industrial application are reviewed. The enhanced photo-initiation system, the dynamics of photoiniti...The recent developments in the photoinitiated cross-linking of polyethylene and the significant breakthrough of its industrial application are reviewed. The enhanced photo-initiation system, the dynamics of photoinitiated crosslinking, the optimum conditions, the crystal morphological structures and related properties, and the photo- and thermo-oxidation stability of photocrosslinked polyethylene (XLPE) materials have been elucidated systematically. A new technique for producing photocrosslinked XLPE-insulated wire and cable is described in detail. It can be expected that the future applications of photocrosslinking technique of polyolefins will be very promising.展开更多
The degradation of crosslinked polyethylene (XLPE) cable insulation during service, such as thermo-oxidation and water treeing may lead to a premature electrical breakdown of the XLPE insulation cables. Therefore, it ...The degradation of crosslinked polyethylene (XLPE) cable insulation during service, such as thermo-oxidation and water treeing may lead to a premature electrical breakdown of the XLPE insulation cables. Therefore, it is necessary to optimize the period of replacement to evenly distribute the replacement cost by ascertaining the deterioration degree. Estimation of the aging degree is at present the most important task for diagnosis of the residual lifetime of the power cable insulation. This paper presents a study on the changes in the dielectric properties of the thermally aged XLPE cables in the frequency range from 0.07～10 MHz. Based on electrical and physicochemical characterization, some new "dactylograms" for the thermally aged XLPE cable insulation have been proposed.展开更多
基金Supported by the National Key Technologies Research and Development Program of China During the 11th Five-Year Plan Period(No.2007BAE19B01)the Industrial Research Projects of the Science and Technology Plan of Ningbo City,China (No.2007B10033)
文摘Two commercial crosslinkable polyethylene insulation cable granules, designed for 110 and 35 kV voltage insulation, with similar crosslinking temperature but different melting temperature, were chosen as experimental samples for examining their linear dynamic responses during cross-linking. It has been found that the gel contents of cable compounds for 110 and 35 kV insulation are almost the same after they have been cross-linked at the same temperature, pressure and time. And the sample melts show the similar dependence of the dynamic storage modulus, G; on strain. On the other hand, the dynamic temperature ramp test and the dynamic time sweep test indicate that the samples exhibit different dynamic viscoelastic responses during their crosslinking. An expression for describing their erosslinking process was proposed via probing rheokinetics of crosslinking for the two samples.
基金The project was successively supported by the National Natural Science Foundation of China(No. 5880104, No. 59543002 and No. 59773030).
文摘The recent developments in the photoinitiated cross-linking of polyethylene and the significant breakthrough of its industrial application are reviewed. The enhanced photo-initiation system, the dynamics of photoinitiated crosslinking, the optimum conditions, the crystal morphological structures and related properties, and the photo- and thermo-oxidation stability of photocrosslinked polyethylene (XLPE) materials have been elucidated systematically. A new technique for producing photocrosslinked XLPE-insulated wire and cable is described in detail. It can be expected that the future applications of photocrosslinking technique of polyolefins will be very promising.
基金Major Research Project of Shanghai City(No. 045211024)
文摘The degradation of crosslinked polyethylene (XLPE) cable insulation during service, such as thermo-oxidation and water treeing may lead to a premature electrical breakdown of the XLPE insulation cables. Therefore, it is necessary to optimize the period of replacement to evenly distribute the replacement cost by ascertaining the deterioration degree. Estimation of the aging degree is at present the most important task for diagnosis of the residual lifetime of the power cable insulation. This paper presents a study on the changes in the dielectric properties of the thermally aged XLPE cables in the frequency range from 0.07～10 MHz. Based on electrical and physicochemical characterization, some new "dactylograms" for the thermally aged XLPE cable insulation have been proposed.
