电缆接头尖刺缺陷局部放电发展过程的研究  

Study on Development of Partial Discharges at the Defect Caused by a Needle Damage to a Cable Joint

作　　者：常文治 李成榕 苏錡 葛振东 

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206

出　　处：《中国电机工程学报》2013年第7期192-201,1,共10页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973项目)(2009CB724508)~~

摘　　要：硅橡胶绝缘预制型电缆接头由于外半导电层存在尖端突起而引发绝缘故障的现象时有发生,探寻此类绝缘缺陷局部放电发展变化的规律,可为在线评估缺陷严重程度提供依据。在35kV电缆预制型接头上设置尖刺缺陷,使用逐级升压法激发出缺陷的局部放电信号并加速缺陷劣化,在劣化程度加剧后保持外施电压恒定直至绝缘失效。记录并分析了缺陷开始劣化直至绝缘失效全过程的局部放电信号,生成了单位时间内局部放电能量随试验时间的变化曲线。基于局部放电能量的发展变化规律,将局部放电发展全过程划分为5个阶段,得到了各阶段局部放电相位特征谱图,在此基础上提取了3个局部放电特征量。研究结果表明,在尖刺缺陷局部放电的发展过程中,相位特征谱图的形貌特征发生变化,3个特征量呈现单一增大的趋势,且在局部放电后期陡然增大,通过对局部放电相位分布特征及特征量变化趋势的综合分析,可以更加准确的评估尖刺缺陷的严重程度。Insulation faults caused by the damages to the semi-conductive outer layer of silicon rubber prefabricated cable joints often occur.Studies on the partial discharges（PDs） development of such insulation defects,may help on the on-line assessment of their severity.In this paper,a needle damage was made in a 35 kV prefabricated cable joint.The voltage applied to the test object was raised step by step,which causes PDs and accelerates the deterioration of insulation.After the defect was seriously deteriorated,a constant voltage was applied until insulation breakdown.During the tests,PDs were all recorded and analyzed.The trend of PD energy per unit time was obtained.The development of PDs was classified into five stages according to the trend of PD energy.For each stage,phase characteristic spectrograms were determined,and three characteristic parameters were extracted.The investigation results showed that,during the development of PDs,there were differences in phase characteristic spectrograms at different stages.They increased monotonically,and then suddenly increased in the last period.Based on these characteristics,the severity of needle-damaged insulation defects could be more accurately assessed.

关 键 词：电缆接头 硅橡胶绝缘 尖刺缺陷 局部放电 绝缘劣化 状态评估 

分 类 号：TM835[电气工程—高电压与绝缘技术]