硅橡胶/胶联聚乙烯界面金属颗粒沿面放电严重程度的评估  

Assessment of Creeping Discharge Initiated by Metal Particles on the Silicone Rubber/XLPE Interface in Cable Joints

作　　者：常文治[1] 阎春雨[1] 李成榕[2] 毕建刚[1] 葛振东[3] 

机构地区：[1]中国电力科学研究院 [2]新能源电力系统国家重点实验室(华北电力大学) [3]国网北京市电力公司

出　　处：《电工技术学报》2015年第24期245-254,261,共11页Transactions of China Electrotechnical Society

摘　　要：硅橡胶绝缘预制型电缆接头由于制作工艺问题在硅橡胶/胶联聚乙烯界面上形成半导电或金属颗粒缺陷最终导致沿面击穿的故障时有发生。探寻硅橡胶/胶联聚乙烯界面金属颗粒沿面绝缘缺陷局部放电的发展过程,可为电缆中间接头放电严重程度的评估提供依据。在35k V电缆中间接头硅橡胶/XLPE界面上设置金属颗粒缺陷,通过逐级升高电压激发出局部放电信号并加速缺陷发展。测量了局部放电起始直至绝缘击穿全过程中的局部放电信号,生成了单位时间内局部放电平均能量、总能量及放电次数共计三个表征参量随时间的变化曲线。基于曲线的发展变化规律,将局部放电发展全过程划分为四个阶段,得到了表征各阶段局部放电重复率及平均放电量相位分布特征的?-n、?-qave二维谱图以及灰度图,从中提取了两个能够表征各阶段局部放电统计规律的特征量。研究结果表明,在预设缺陷局部放电的发展过程中,局部放电相位谱图的形貌特征发生变化,从相位谱图中提取的两个局部放电特征量均呈现单一增大的趋势,且在放电后期增长速率加快。基于对局部放电相位分布特征及特征量变化趋势的综合分析,提出了一种硅橡胶/胶联聚乙烯界面金属颗粒沿面放电严重程度的评估方法。Creeping breakdown caused by metal particles on the silicone rubber/XLPE interface of silicon rubber prefabricated cable joints often happens. Study on the development process of such insulation defect-led partial discharge（PD） can serve as a basis for the assessment of its severity level. In this paper, metal particles were sandwiched on the rubber/XLPE interface of a 35 k V prefabricated cable joint so as to simulate a creeping defect. The applied voltage on the test object was raised step by step to initiate the partial discharge and accelerate the degradation of the failure, where PD signals in the whole process were all measured. PD average energy, whole energy and PD number per unit time were chosen as the characterization parameters. The developing trends of these characterization parameters versus discharge time were then obtained. According to the developing trends, the entire developing process of PD was classified into four developing stages. For each stage, two-dimensional histograms of ？-n and ？-qave relationships as well as the grey-scale maps were generated, from which the phase distribution of PD repetition rate and PD average amount can be observed. Two features for the PD process were extracted from these-phase characteristic spectra. The experiment results showed that visual differences between the phase characteristics spectra of each stage exist. The extracted features monotonically increase as the PD aggravates, and the growth rate increases in the late PD development. Based on the morphology of phase characteristic spectra and the variation of each PD development stage, the severity of creeping discharge arising from metal particle defect on silicone rubber/XLPE interface can be assessed.

关 键 词：电缆接头 硅橡胶/XLPE界面 局部放电 发展过程 严重程度 

分 类 号：TM855[电气工程—高电压与绝缘技术] TM21[一般工业技术—材料科学与工程]