热处理前后非脱气交联聚乙烯的介电性能和机械性能分析（英文）  

Investigation of Dielectric and Mechanical Properties of Undegassed XLPE Cable with Thermal Treatment

作　　者：LI Huan LI Jianying WANG Qimeng ZHOU Yunjie LI Honglei 

机构地区：[1]State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University [2]Electric Power Research Institute of Shanghai Electric Power Corporation [3]Maintenance Subsidiary of Shanghai Electric Power Corporation

出　　处：《高电压技术》2015年第4期1237-1242,共6页High Voltage Engineering

基　　金：Project supported by Key Technology and Engineering Demonstration Application of High Conveying Capacity High-Voltage Cable and Accessories(5442GY120040)

摘　　要：In order to investigate the influence of cross-linking byproducts on dielectric and mechanical properties of 110k V cross-linked polyethylene(XLPE)cable insulation,we selected the undegassed XLPE cable insulation which is heated at 70℃in laboratory for different duration in terms of heating time,to prepare XLPE samples with different mass loss ratio.We carried out Fourier transform infrared spectroscopy(FTIR)test,electric breakdown test at 50 Hz,pulsed electro-acoustic(PEA)measurement and tensile test for XLPE samples.In FTIR spectrogram,the characteristic absorption peaks were observed to appear at 1 680 cm-1 and 1 600 cm-1,which can be related to two kinds of cross-linking byproducts includingα-methylstyrene and acetophenone.The intensity of these absorption peaks decreases with the increase of mass loss ratio.It can be proposed that the mass loss of XLPE samples in the process of thermal treatment is caused by volatiliztion ofα-methylstyrene and acetophenone.Therefore,the change of mass loss ratio can reflect the change of content ofα-methylstyrene and acetophenone in the process of thermal treatment.The results of electric breakdown test showed that the reduction ofα-methylstyrene and acetophenone leads to the enhancement of electric breakdown strength at 50 Hz.PEA measurement results showed that heterocharge is produced and accumulated when cross-linking byproducts are present,whereas no heterocharge is found whenα-methylstyrene and acetophenone are absent.The formation of heterocharge is attributed to ionization of cross-linking byproducts under electric stress.Based on these results,it can be suggested that when AC electric field is applied on XLPE samples,the occurrence of ionization of cross-linking byproducts results in the increase of free carriers in XLPE insulation,leading to a lower electric breakdown strength.The results of tensile test showed that tensile strength is proportional to the mass loss ratio of XLPE samples,which suggests that cross-linking byproducts can reduce the tensile strenIn order to investigate the influence of cross-linking byproducts on dielectric and mechanical properties of 110 kV cross-linked polyethylene（XLPE） cable insulation, we selected the undegassed XLPE cable insulation which is heated at 70 ℃ in laboratory for different duration in terms of heating time, to prepare XLPE samples with different mass loss ratio. We carried out Fourier transform infrared spectroscopy（FTIR） test, electric breakdown test at 50 Hz, pulsed electro-acoustic（PEA） measurement and tensile test for XLPE samples. In FTIR spectrogram, the characteristic absorption peaks were observed to appear at 1 680 cm-1 and 1 600 cm-1, which can be related to two kinds of cross-linking byproducts including α-methylstyrene and acetophenone. The intensity of these absorption peaks decreases with the increase of mass loss ratio. It can be proposed that the mass loss of XLPE samples in the process of thermal treatment is caused by volatiliztion of α-methylstyrene and acetophenone. Therefore, the change of mass loss ratio can reflect the change of content of α-methylstyrene and acetophenone in the process of thermal treatment. The results of electric breakdown test showed that the reduction of α-methylstyrene and acetophenone leads to the enhancement of electric breakdown strength at 50 Hz. PEA measurement results showed that heterocharge is produced and accumulated when cross-linking byproducts are present, whereas no heterocharge is found when α-methylstyrene and acetophenone are absent. The formation of heterocharge is attributed to ionization of cross-linking byproducts under electric stress. Based on these results, it can be suggested that when AC electric field is applied on XLPE samples, the occurrence of ionization of cross-linking byproducts results in the increase of free carriers in XLPE insulation, leading to a lower electric breakdown strength. The results of tensile test showed that tensile strength is proportional to the mass loss ratio of XLPE samples, which suggests that cross-lin

关 键 词：XLPE电缆 热处理 交联聚乙烯绝缘电缆 力学性能 质量损失率 甲基苯乙烯 电击穿强度 介质 

分 类 号：TM855[电气工程—高电压与绝缘技术]