The aging characteristics of the XLPE insulation of 110 kV power cables in the initial stage of operation are studied in this paper.The XLPE insulation from cables with different running time was tested by using elect...The aging characteristics of the XLPE insulation of 110 kV power cables in the initial stage of operation are studied in this paper.The XLPE insulation from cables with different running time was tested by using electrical and physicochemical methods,from which the degradation state of XLPE under multiple stresses during operation was derived.The broadband dielectric spectrum test taken from 10–1 to 10^(6) Hz showed that the dielectric constant and dielectric loss of the XLPE insulation first decrease and then increase with the increase of cable running time,which show obvious variation until 10 years of operation.The AC breakdown strengths of the XLPE insulation of operated cables with the service year no longer than 10 years were higher than that of new cables.The mechanical properties of the XLPE insulation showed no dependence with the cable running time.The crystallinity and perfection of the crystallization area were found to be enhanced during operation and the polar functional groups inside the XLPE insulation were found to be determined not only by the cross-linking by-products but also by the oxidation process during cable operation.The experimental results in this paper are important for improving the operation reliability and reducing the maintenance costs of the cables.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
文摘The aging characteristics of the XLPE insulation of 110 kV power cables in the initial stage of operation are studied in this paper.The XLPE insulation from cables with different running time was tested by using electrical and physicochemical methods,from which the degradation state of XLPE under multiple stresses during operation was derived.The broadband dielectric spectrum test taken from 10–1 to 10^(6) Hz showed that the dielectric constant and dielectric loss of the XLPE insulation first decrease and then increase with the increase of cable running time,which show obvious variation until 10 years of operation.The AC breakdown strengths of the XLPE insulation of operated cables with the service year no longer than 10 years were higher than that of new cables.The mechanical properties of the XLPE insulation showed no dependence with the cable running time.The crystallinity and perfection of the crystallization area were found to be enhanced during operation and the polar functional groups inside the XLPE insulation were found to be determined not only by the cross-linking by-products but also by the oxidation process during cable operation.The experimental results in this paper are important for improving the operation reliability and reducing the maintenance costs of the cables.
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.
