绝缘子雾霾天气下泄漏电流特性的研究

Research on Leakage Current Characteristics of Insulator under Fog and Haze

雾霾天气中,绝缘子处于极为不利的运行状态,污闪事故发生的可能性大为增加。为研究雾霾天气对绝缘子运行造成的影响,在高压实验室中模拟了燃煤和汽车尾气导致的雾霾环境,测量了在不同雾霾成分作用下绝缘子表面的泄漏电流。对实验中采集到的泄漏电流信号利用小波阈值去噪法进行去噪处理,对不同的阈值选择方法所得到的阈值去噪效果的优劣进行了比较,得到了最佳的阈值选择法。利用总体最小二乘旋转不变子空间算法提取泄漏电流的特征参数,并对其特性进行了分析。实验结果表明,含有SO_4^(2-)的雾霾比含有NO_3^-的雾霾对绝缘子泄漏电流的影响更大。

In recent years, serious air pollution causes that fog-haze occurs frequently in our country. In fog-haze, the insulator is under extremely unfavorable operating state, the possibility of flash over accident is greatly increased. In order to research the influence of insulator caused by the haze weather, the pollutions caused by coal and automobile exhaust were simulated, the insulator leakage currents resulted by the different haze components were measured. The leakage current signals were collected and denoised by using wavelet threshold denoising method. Different selection method might lead to different threshold values. The pros and cons for these values were compared and the optimal threshold selection method was obtained. Characteristic parameters of leakage currents were extracted by TLS-ESPRIT algorithm and these characteristic parameters were researched. Experimental results show that the fog-haze containing leads to bigger insulator leakage current than that contains.