Effect of Short Time and High Temperature on the Microstructure and Electrical Properties of Insulation of Blended Polypropylene Cable
Under the promotion of the"dual carbon"background,elastomer/polypropylene(PP)blends are regarded as recyclable cable main insulation materials with great application potential.In this paper,the blend polypropylene cable insulation layer slice is used as the research object to simulate the short time high heat phenomenon of the insulation layer when the cable is faulty,so as to study the effect of short time high heat on the microstructure and electrical properties of blended polypropylene insulation.Firstly,the sample was extracted from the cable insulation layer and subjected to short time high heat treatment.Secondly,the changes of physical and electrical properties of insulation samples before and after short time high heat treatment were compared.Finally,the microstructure changes in the insulation of mixed PP cable during short time high heat treatment were discussed and the influence mechanism of the microstructure changes on its electrical properties was analyzed.The results show that the continuity of the insulation phase deteriorates,the area of the elastomer phase decreases,and the number of interfacial layers increases after the cable insulation is subjected to short time high heat treatment.The molecular chain inside the insulation was broken,and the crystallinity decreased by 2.42％.Under industrial frequency,the insulation dielectric constant rises by 0.04,and the dielectric loss rises by 0.001 04.The number of deep traps inside the insulation increased,and the breakdown field strength decreased by 1.4％.
high voltage cablepolypropylene/elastomer blendshort time high heat treatmentmicrostructureelectrical property
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维普
