基于小波分析的时差法研究  

The Method of Time Difference Based on Wavelet Analysis

作　　者：冯煊[1] 余民郭[2] 孙珊[3] 

机构地区：[1]湖北省电力公司检修分公司,湖北武汉430077 [2]湖北黄石供电公司,湖北黄石435000 [3]武汉大学电气工程学院,湖北武汉430072

出　　处：《湖北电力》2012年第4期21-23,共3页Hubei Electric Power

摘　　要：文章利用小波分析能准确检测信号奇异点的特征提出了基于小波分析的时差法。该方法能准确检测出故障时刻与差流产生时刻之间的差异,正确判断变压器区内外故障,有效防止了变压器区外短路时因电流互感器饱和而造成的差动保护误动。并以某一系统为例,在PSCAD中进行了仿真,验证了此方法的有效性。In this paper,according to the characteristic that wavelet analysis has the ability of detecting signal singularities accurately,a time difference method based on wavelet analysis is proposed.Using the suggested method,the difference between fault occurrence time and differential-current appearance time can be precisely detected,and it can be applied for discriminating the internal faults and external faults of power transformer,consequently,in the case of a fault happening outside power transformer,the misoperation of differential protection caused by the iron core saturation of current instrument transformer can be avoided.In order to verify the effectiveness of this time difference method,the simulation analysis on a system is carried out in PSCAD.

关 键 词：小波分析 奇异点 时差法 变压器 差动保护 

分 类 号：TM77[电气工程—电力系统及自动化]