高压交联聚乙烯电缆绝缘劣化试验分析  

Test and Analysis of Insulation Deterioration of XLPE Power Cable

作　　者：王立[1] 杜伯学[1] 任志刚[2] 

机构地区：[1]天津大学电气与自动化工程学院,天津300072 [2]北京电力科学研究院,北京100075

出　　处：《高电压技术》2014年第1期111-116,共6页High Voltage Engineering

基　　金：国家自然科学基金(51277131)~~

摘　　要：为掌握运行多年的交联聚乙烯(XLPE)电缆绝缘劣化状况及出现劣化的原因,采用热重法、红外光谱、机械强度试验分析了退运的14条110 kV和220 kV XLPE电缆绝缘。研究了电缆绝缘材料的热稳定性、物质成分及机械性能与电缆绝缘劣化的对应关系,并分析了14条退运电缆历史运行数据。结果表明,14条退运电缆中,有4条电缆绝缘出现了劣化,而这些电缆都经受过穿越故障电流或外部高温;起始分解温度、羰基指数、断裂能对表征XLPE电缆绝缘的劣化状况有很好的一致性,当绝缘出现劣化时,其起始分解温度降低、羰基指数升高、断裂能减小;交联电缆经受大的故障电流冲击或外部高温,都会加快绝缘的劣化。To obtain the degradation condition of insulation in crosslinking polyethylene （XLPE） cables which has been operated for many years, and to understand the mechanism of the degradation, we analyzed the insulation of 14 XLPE cables returned from 110 kV and 220 kV transmission lines using the thermo gravimetric method, infrared spectrum, me chanical strength test. Moreover, we researched the relationship of thermal stability of insulation materials, the material composition and mechanical properties with the degradation, and analyzed the historical operation data of the 14 samples. The results show that four of 14 cables have degradation in their insulation, and all these four cables are heated by fault current or external high temperature. It is also concluded that initial decomposition temperature, hydroxyl index, and fracture energy have good consistency in terms of characterizing the status of XLPE cables＇ insulation degradation： when insulation has degradation, its initial decomposition temperature and fracture energy decrease, and its carbonyl index in creases. The crosslinked cable subjected to large fault current shock or external high temperature will accelerate insulation degradation.

关 键 词：交联聚乙烯 绝缘劣化 热重法 红外光谱 起始分解温度 羰基指数 断裂能 故障电流 

分 类 号：TM751[电气工程—电力系统及自动化]