谐波电场法带电检测直流绝缘子

挂网运行的直流绝缘子数量越来越多,其检测问题日益突出。分析认为,合成绝缘子内导通性故障及零值瓷绝缘子是最难发现、最危险的故障。文中研究了这类故障直流绝缘子的带电检测问题,提出利用直流绝缘子串周围谐波电场带电检测直流绝缘子的新方法,即谐波电场法,并进行了可行性试验与灵敏度分析。现场与实验室可行性试验表明,谐波电场法能够对直流绝缘子进行在线检测。理论分析表明,该方法灵敏度较高,能有效地给出低于一定阻值的零值瓷绝缘子和合成绝缘子内绝缘导通性故障信息。谐波电场法的提出为直流绝缘子带电检测提供了有力手段。

Harmonic Electric Field Method for Live Detecting DC Insulator

It is more and more important to detect the DC insulators because insulators have been coming into use in plenty in power systems. Analyses indicate that the internal insulation defects of composite insulators and the low resistance faults of porcelain insulators are very dangerous and also difficult to be detected. The paper discusses the problem above and proposes a novel method, viz. harmonic electric field method, which utilizes the harmonic electric field distribution of DC insulator to live detect DC insulators. Accordingly, the feasibility and sensitivity are analyzed. Theoretical analysis indicates that harmonic electric field method has higher sensitivity, and can effectively obtain the internal insulation detecting information of composite insulators and faults of porcelain insulators under certain resistance. Test results of lab and field have demonstrated that this method is valid for live detection of fault DC insulator.