玻璃绝缘子老化、污秽与表面放电强度相关性分析

Analysis on Relevance of Surface Discharge Strength to Aging and Pollution of Glass Insulators

为了有效监测绝缘子的表面放电现象、防止闪络发生、保障输电线路的安全运行,开展不同环境下放电强度状态研究。首先,采用紫外脉冲传感器,对不同污秽等级和老化等级的绝缘子进行探测,获取各样本放电的紫外脉冲信号;其次,以绝缘子样本表面的电介质应力变化表征其放电强度,记录和分析不同放电强度的紫外脉冲信号直流分量和谐波分量变化,探究绝缘子污秽等级、老化等级与紫外脉冲信号特征的内在关联;最后,通过绝缘子老化和污秽实验,验证相关理论。实验结果表明:处于污秽和老化状态下的绝缘子,其放电强度与紫外脉冲信号直流分量、谐波分量的幅值均呈正相关关系;在不同污秽、老化等级中,紫外脉冲信号第2—6次谐波分量幅值与放电强度具有较强的正相关性;相比于污秽因素,老化因素对绝缘子放电强度的影响更大。

To effectively monitor the surface discharge phenomenon of the insulator,prevent the occurrence of flashover,and ensure the safe operation of transmission lines,this paper studies the discharge strength of the insulators in different environments.Firstly,it uses the UV pulse sensor to detect the insulators with different fouling levels and aging degrees and obtain the UV pulse signal of each sample.Secondly,it uses the dielectric stress changes on the sample surface to characterize the discharge strength of the insulators,records and analyzes the changes of DC components and harmonic components of the UV pulse signals with different discharge strength so as to explore the internal relationship between the pollution levels and aging levels of the insulators and the characteristics of the UV signals.Finally,the paper verifies the correlation theory through the aging and fouling experiments on the insulator.The results show that the discharge strength of the insulator under the pollution and aging states presents a positive correlation between the DC component and the harmonic component.In different pollution levels,the amplitudes of the 2~(nd)-6~(th) harmonic components of the UV pulse signal have strong positive correlation with the discharge strength.Compared with the pollution factor,the aging factor has a greater impact on the discharge process of the insulator.