基于特高频时频分析的GIS盆式绝缘子缺陷分析

为更有效在现场开展GIS局部放电检测,及时准确发现设备内部缺陷,特别是盆式绝缘子局部放电缺陷,文中研究了基于特高频时频定位分析的GIS局部放电综合定位方法。将多通道时延定位法和多通道小波时频分析法联合应用,通过局部放电特高频信号的时域和频谱变化特征,结合设备内部结构、装配工艺等情况,实现GIS局部放电综合精确定位。该方法在某500kV变电站220kV GIS带电检测中进行了应用,精确定位一处盆式绝缘子表面放电缺陷。表明文中研究的基于特高频时频定位分析的GIS局部放电综合定位方法有助于准确定位GIS内部缺陷,针对性指导设备检修工作,缩短检修时间,有效提高检修效率。

GIS Basin Insulator Defect Analysis Based on Ultra-high Frequency Time-frequency Analysis

For upgrading partial discharge on-site detect level of gas insulated switchgear(GIS),detecting internal defects of equipments quickly and exactly,especially partial discharge defect of basin insulator,this article researched on partial discharge synthetic location method for GIS based on ultra-high frequency time-frequency location analysis.Construction of multi-channel signals time delay location method and multi-channel time-frequency analysis method based on wavelet transform,according to the partial discharge ultra-high frequency signal time and frequency variations,GIS partial discharge synthetic location can be achieved combination of equipment internal structure and assembly process.In 220kV GIS on-site detection of one 500kV substation,this method located surface discharge of a basin insulator exactly.It has confirmed partial discharge synthetic location method for GIS based on ultra-high frequency time-frequency location analysis can locate the GIS internal defects.The application can supervise equipment maintenance pertinently,shorten equipment maintenance time and improve equipment maintenance efficiency.