摘要
绝缘子表面污秽电导率对污闪预警具有重要作用,然而绝缘子表面污秽分布不均,其形成的微小电容对表面电导率的检测产生较大影响。为克服该影响,文中研制了基于相角差的绝缘子表面污秽电导率检测系统,详细介绍了系统检测原理以及系统关键部分的设计和仿真,并在实验室进行了污秽受潮试验,分析了污秽表面电导率随受潮时间的变化规律。结果表明:污秽干燥时,表面电导率很小;随着受潮的进行,表面电导率不断增大;污秽饱和受潮时,表面电导率达到最大;污秽过饱和受潮、流失时,表面电导率不断减小。因此,可将污秽受潮过程分为3个区段,受潮区、饱和区和流失区,其中,防污闪工作中应重点关注受潮区。研究结果表明该系统能够有效地检测绝缘子表面污秽电导率,可为污闪防治工作提供指导。
The contamination conductivity on the surface of an insulator plays an important role in the warning of pollution flashover. However, as the contamination is usually inhomogeneous, the resulting micro-capacitance exerts great influence on the detection of the insulator surface conductivity. To tackle this problem, the authors developed a method for detecting the contamination conductivity on the surface of an insulator based on phase angle difference. In this study, the detection theory of the system was analyzed,and the key parts of the system were designed and simulated. Then, contamination wetting tests were conducted in laboratory to obtain the changing rule of the surface conductivity of an insulator. The results show that： 1）the surface conductivity is small when the contamination is dry; 2）the surface conductivity increases as the contamination gets wet; 3）the surface conductivity reaches its maximum when the contamination wetting is saturated; and 4）the surface conductivity decreases when the damp in contamination is over-saturated and the contamination drains. Therefore, the wetting process can be divided into three stages, i.e. wetting, saturation, and draining stages. More attention should be paid to the wetting stage in the prevention of pollution flashover. This research shows that the present system can effectively detect contamination conductivity on insulator surface and may provide guidance for the prevention of flashover.
出处
《高压电器》
CAS
CSCD
北大核心
2016年第9期164-169,共6页
High Voltage Apparatus
基金
特高压工程技术(昆明
广州)国家工程实验室开放基金(NEL201305)
广东省自然科学基金资助项目(2014A030310371)~~
关键词
绝缘子
污秽
表面电导率
检测
研制
相角差
insulator
contamination
surface conductivity
detection
development
phase angle difference
