绝缘子泄漏电流去噪研究  

Research on denoising of insulator leakage current

作　　者：黄建才[1] 朱永利[1] 李丽芬[1] 胡晟[1] 

机构地区：[1]华北电力大学控制与计算机工程学院,河北保定071003

出　　处：《电力系统保护与控制》2012年第20期44-51,共8页Power System Protection and Control

基　　金：国家自然科学基金项目(60974125)~~

摘　　要：为了去除绝缘子泄漏电流中的噪声,提出了傅里叶变换和小波变换相结合的去噪方法。解决了采用该方法去噪时涉及的关键问题,包括周期分量的选择、母小波的选择、小波分解层数的确定、小波阈值的选择。根据对泄漏电流中各成分的频谱分析,给出了提取周期分量的阈值;根据提取泄漏电流突变值的效果,确定了最佳母小波;根据提取周期分量后剩下成分的频率分布,提出了小波分解层数的计算公式;根据绝缘子泄漏电流波形的多样性,给出了不同情况下的阈值选择。以现场绝缘子泄漏电流和高压试验数据为处理对象,采用所提的方法进行了去噪。去噪结果表明,所提方法既能平滑泄漏电流,又能有效保留特征数据,具有重要的实用价值。In order to denoise the insulator leakage current, the denoising method is proposed, which combines Fourier transform with wavelet transform. The key problems during denoising are solved by using this method, including periodic component selection, mother wavelet selection, wavelet decomposition level number and wavelet threshold selection. The threshold for extracting the periodic components is given after the frequency spectrum of leakage current is analyzed. The optimal mother wavelet is given after the results of extracting the mutation values of leakage current are compared. Based on the frequency distribution of the remaining components after extracting the periodic ones, the calculation formula for the number of wavelet decomposition level is proposed. By analyzing the different leakage currents, the wavelet threshold selection is given. The proposed method is used to denoise the field insulator leakage current and the data gathered in the high voltage experiment respectively. The results show that the proposed method can smooth the leakage current and effectively keep the feature data. So, this method has important practical value.

关 键 词：绝缘子 泄漏电流 傅里叶变换 小波变换 噪声 

分 类 号：TM216[一般工业技术—材料科学与工程]