一种抗噪声的电压暂降时刻检测方法  

A Voltage Sag Time Detection Method with Anti-noise Feature

作　　者：葛成余[1] 朱颂怡 韩先鹤[1] 张大海[3] 

机构地区：[1]国电南瑞科技股份有限公司,江苏省南京市211106 [2]南京中德保护控制系统公司,江苏省南京市210003 [3]北京交通大学电气工程学院,北京市海淀区100044

出　　处：《智能电网》2017年第5期417-420,共4页Smart Grid

摘　　要：电压暂降对电力系统和电力用户带来严重威胁,对电压暂降进行检测具有重要意义。小波分析方法能够有效识别电压暂降时刻,但噪声的存在会导致小波分析方法的性能下降甚至失效。该文利用信号与噪声在小波变换各尺度上特性的不同,提出运用多尺度小波信息,将高频和次高频小波分量对应相乘,在乘积信号中再寻找局部模极大值来判断电压暂降起止时刻。新方法能够克服噪声影响,提高电压暂降时刻检测的准确性。算例验证了该文新方法的有效性。Voltage sag seriously endangers both power grid and power customers, so the detection of voltage sag is of great importance. Wavelet analysis method works well for detecting voltage sag time, but the existence of noise can reduce the advantages of wavelet analysis method or even make it ineffective. The difference of signal and noise in different wavelet scales is used, and a method to apply multi-scale wavelet information is proposed in this paper. By multiplying the highest frequency and sub-high frequency wavelet components and searching the local maxima from the product, the start and end time of voltage sag can be identified. The proposed method can suppress the noise and improve the accuracy of detecting voltage sag time. Simulation result validates the effectiveness of the proposed method.

关 键 词：电能质量 电压暂降 小波分析 抗噪声 

分 类 号：TM714.2[电气工程—电力系统及自动化]