采用数学形态学的弧光接地过电压识别方法  

Identification of Arc Grounding Over-voltage Using Mathematical Morphology Transform

作　　者：司马文霞[1] 冉锐[1] 袁涛[1] 姚爱明 马立群 杨岱坤 

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030 [2]临安供电局,临安311307

出　　处：《高电压技术》2010年第4期835-841,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2009CB724504)~~

摘　　要：配电网单相接地故障中危害较大的间歇性弧光接地占绝大多数。与目前广泛采用的发生接地故障后不区分故障性质直接补偿故障电流的经消弧线圈接地方式相比,依据过电压在线监测系统获取的故障过电压波形对故障类型进行快速准确的识别并进行相应的处理,抑制措施更加准确,可进一步提高系统和电气设备的安全运行水平。为此,通过对中性点不接地系统大量实测过电压波形进行分析,利用故障期间间歇性弧光接地存在多次暂态过程而金属性接地只存在1次暂态过程的特点,采用COOCG形态滤波算子提取线路零序电压标么值的奇异信号作为特征量,对间歇性弧光接地过电压进行识别,从而实现对系统单相接地类型的判别功能。经大量仿真和实测波形证明,该方法在不同故障条件下均有较好的准确性和有效性。Single-phase grounding fault is one of the main forms of power system faults,and as the major case,intermittent arc grounding in distribution network is very dangerous to system. According to over-voltage fault waveform records of on-line monitoring system,fault types can be identified and be dealt with quickly and accurately. Comparing with resonant grounding method,which compensates fault current directly without distinguishing grounding faults＇ type when grounding fault occurs,the suppression measure in this paper is more accurate and it will enhance the level of safety of power system and electrical equipment further. We analyzed a lot of measured over-voltage waveforms of an isolated neutral system. There are many transient processes in intermittent faults,however,only one in metal grounding faults during the existence of faults,so a criterion which extracts characteristic quantity from singular signal of transmission line zero-sequence voltage＇s per unit value by COOCG arithmetic operators to identify intermittent arc grounding over-voltage in order to achieve the identification of single-phase grounding types is proposed. By processing a large number of simulation and measured waveforms,the identification results show that the proposed method is accurate and effective in various fault conditions.

关 键 词：配电网 中性点不接地系统 金属性接地 间歇性弧光接地 故障识别 形态滤波 

分 类 号：TM864[电气工程—高电压与绝缘技术]