为了有效地监测金属氧化物避雷器的绝缘工况,提出一种基于改进经验模态分解的泄漏电流去噪方法.首先,依据泄漏电流波形和幅值的综合相似度对信号端点进行延拓以抑制端点效应,进而根据本征模态函数的平滑度和相关性的综合指标重构无噪声干扰的泄漏电流信号;然后,通过坐标下降法对权重参数进行动态修正和更新,保证重构信号的合理性和准确性;最后,通过仿真和实验验证所提方法可以有效去除泄漏电流信号中的噪声干扰,且能判定出异常监测值,符合工程的实际要求.
In order to effectively monitor the insulation condition of metal oxide arresters,a leakage current denoising method based on improved empirical mode decomposition is proposed.Firstly,the end point is extended to suppress the end effect by considering both waveform and amplitude similarity comprehensively,and then the leakage current signal without noise is reconstructed according to the comprehensive index that incorporates the smoothness and correlation of the intrinsic mode function.Subsequently,the weight parameters were dynamically adjusted and updated through the coordinate descent method to ensure the rationality and accuracy of the reconstructed signals.Finally,through analysis of simulated and measured data,it is confirmed that the proposed method can effectively eliminate the noise interference in the leakage current signal,and identify abnormal monitoring values,meeting the practical requirements of engineering.