采用快速傅里叶变换(FFT)实现泄漏电流中周期分量和非周期分量的分离,给出了分离2种分量时的阈值。采用改进的固有时间尺度分解(ITD)方法实现非周期分量的去噪,给出了采用ITD去噪时的阈值。引入两端延拓解决了ITD的端点效应问题,提高了采用ITD分析的准确性。以高压试验中采集到的绝缘子泄漏电流为处理对象.采用所提方法对其进行了去噪。结果表明:所提的方法既能平滑信号,又能有效保留特征数据。
The FFT(Fast Fourier Transform) is applied to separate the periodic and non-periodic components of leakage current and the corresponding threshold is given. The improved ITD (Intrinsic Time-scale Decomposition) is applied to denoise the non-periodic components and the corresponding threshold is given. The extension is introduced to both ends of ITD to avoid the end effect,which improves its decomposition accuracy. The proposed method is applied to the insulator leakage current measured in high-voltage experiment and the denoising result show that,the proposed method smoothes the leakage current while keeps the feature data effectively.