电力系统中金属氧化物避雷器的监测与诊断

Monitoring and diagnosis of MOV surge arrester in power networks

由于避雷器运行中通过泄漏电流,以及外部环境中各种干扰因素的存在,会引起避雷器的劣化,因此有必要对金属氧化物MOV(MetalOxideVaristor)避雷器进行监测,及时诊断故障。目前国内外各种有关MOV避雷器的离线或在线监测与诊断方法,大多数是基于其泄漏电流的测量而进行研究的。论文讨论了MOV避雷器现有的主要诊断方法:参考电压的变化、U-I特性的判别、功耗测量、三次谐波分析法和MOV温度检测,并对它们的优、缺点进行了详细分析,其中MOV温度能反映避雷器的运行状态,所以检测MOV阀片温度将是一种得到广泛应用的MOV避雷器监测和诊断方法。

Because of the leakage current passing through it and the various destruct factors in surrounding environment ,the MOV(Metal Oxide Varistor)surge arresters may degrade during their service.So it is necessary to monitor the working condition and to diagnose all faults of MOV surge arresters.There are various monitoring and diagnostic methods for MOV surge arrester,either on-line or off-line.Most of them are based on the measuring of leakage current.The important methods are discussed:reference voltage change,U-I characteristics monitoring,powers loss measurement ,third order harmonic analysis,MOV temperature measurement.Their advantages and weak points are analyzed.The MOV temperature can reflect the working state of MOV surge arrester and be applied for its monitoring and diagnosis,which will have wide use.