污秽复合绝缘子泄漏电流波形频谱特征

Research on Leakage Current Waveform Spectrum Characteristics of Artificial Pollution Composite Insulator

为了解复合绝缘子在污闪过程中泄漏电流变化特征,在人工雾室中开展了复合绝缘子污闪试验研究,测量和分析了试验过程中泄漏电流波形的时域和频域特征。分析结果表明,泄漏电流幅值、基波、三次谐波和五次谐波相互间具有较强的相关性,提出以泄漏电流最大值(Im)、总谐波失真率(THD)、泄漏电流基波相位差(θ)表征泄漏电流频谱特征;临闪时,泄漏电流具有幅值高、谐波含量少、泄漏电流基波与电压间相位差小的特点。研究结果为建立基于泄漏电流特征量的污闪预警系统提供了依据。

In order to know about the change features of leakage current during the pollution flashover process of composite insulators, the study of the pollution flashover test on composite insulator is presented in the artificial fog cabinet. The characteristics of leakage current waveforms in time-domain and frequency-domain are measured and analyzed during the test. The analysis results show that the amplitude of leakage current, fundamental harmonic, the third harmonic and fifth harmonic have a strong correlation,the maximum of leakage current（Im）,the rate of total harmonics（THD） and the phase difference of fundamental harmonic（θ） can be used for the representation of the characteristics of frequency spectrum of leakage current is presented. The change and development of leakage current is closely related to discharge intensity, and the leakage current has the characteristics of high amplitude, small part of harmonic and smll phase difference between the fundamental harmonic and voltage before the flashover is coming.The test results can be used as reference for pollution flashover forecasting system based on the characteristics of leakage current.