摘要
陡波前冲击击穿电压试验是检验盘形绝缘子质量的重要指标。以前的研究者开展了大量陡波下绝缘子击穿过程的研究,以提高绝缘子头部的内绝缘强度,进而提高盘形绝缘子的耐陡波性能;但是鲜有研究关注陡波前冲击电压下绝缘介质表面的放电过程。研究陡波下绝缘介质表面的放电特性对于揭示陡波下绝缘子的击穿机理具有重要意义,同时有助于研究RTV涂层带来的盘形绝缘子陡波击穿性能的变化。陡波下绝缘介质表面的闪络路径是研究陡波下放电特性的重要因素。利用高速摄影仪分别拍摄了涂与不涂RTV的绝缘子在不同陡度电压下的放电路径照片,分析了电压的陡度和涂层参数与放电路径的关系。研究结果表明,放电路径与陡波前冲击电压的陡度有密切关系,陡度越高,放电路径具有越＂沿面＂的趋势。绝缘子涂覆RTV涂层后,陡波下的放电路径具有更＂沿面＂的趋势,陡度大于200 kV/μs时,其放电路径就已经完全＂沿面＂了。涂覆RTV使得绝缘件颈部的电场增大,促使涂RTV后的绝缘子在陡波前冲击电压下起弧后,电弧更易＂沿面＂发展。
Steep-front impulse voltage test is one of main methods to evaluate quality of cap and pin insulators. A lot of investigations are carried out on breakdown process under steep-front impulse to enhance internal insulation strength of head part of the insulators to improve steep front impulse breakdown performance. However, few studies on discharge process of dielectric surfaces under steep-front impulse voltage are reported. Surface discharge features of the insulators are of great importance to reveal breakdown mechanism of insulators under steep-front impulse voltage and study reason of decline of steep-front impulse voltage performance caused by room temperature vulcanized（RTV） coating. In this paper, high-speed photographers were used to record discharge path on porcelain insulators with and without RTV surfaces under both power frequency and steep-front impulse voltages with different steepness. Firstly, influence of impulse voltage steepness on discharge features was investigated. Experimental results show that discharge path depends significantly on steep-front impulse voltage steepness; the higher the steepness is, the greater the trend of along-surface development will be. RTV coatings on insulators will give rise to discharge path with more along-surface trend. When steepness is higher than 200 k V/μs, the discharge path will completely along surface. RTV coating can distort the electric field at neck of the insulator and thus enhance arc development along insulator surface.
作者
邓桃
梁曦东
姚一鸣
丁嘉靖
张学军
DENG Tao;LIANG Xidong;YAO Yiming;DING Jiajing;ZHANG Xuejun(State Key Lab of Control and Simulation of Power Systems and Generation Equipments（Dept.of Electrical Engineering,Tsinghua University）,Haidian District,Beijing 100084,China;China Electric Power Research Institute,Haidian District,Beijing 100192,China)
出处
《电网技术》
EI
CSCD
北大核心
2018年第11期3827-3832,共6页
Power System Technology
基金
国家自然科学基金项目(51577099)~~
关键词
陡波前冲击电压
RTV涂层
放电特性
路径
陡度
场强
steep-front impulse voltage
RTV coating
discharge characteristic
path
steepness
electric field
