【摘要】 金属氧化物避雷器(metal oxide arrester,MOA)是电力系统过电压保护的主要装置,对MOA进行在线监测是保证电力系统安全运行的重要手段。监测MOA的运行状况主要是监测其阻性泄漏电流。针对目前几种MOA阻性电流提取方法存在的问题,根据A、B、C三相电压过零时流过避雷器的全电流与构成它的阻性和容性电流之间的相互关系,提出了一种新的阻性电流提取方法,并推导出了该方法的数学公式。最后分别建立了在系统电压正常和有谐波状态下的仿真模型,对该方法进行验证。结果证实了该方法能有效地滤除电网电压3次谐波和相间耦合电容产生的干扰,为MOA性能的判断提供了可靠的依据。更多还原

【Abstract】 Metal oxide arresters(MOA) are the main over-voltage protection devices in power systems.The on-line monitoring of MOA is an important method to ensure the safety of power systems.The measuring of the resistive leakage current of MOA is the main methods of monitoring the conditions of MOA.According to the weakness of the existing methods used in extracting resistive current,a new extracting method based on the relationship between total current and its component parts resistive current and capacitive current for resistive current of MOA at A,B,C three-phase voltage’s zero-point was proposed,and the digital formula of this method was deduced.At last,the simulation models under normal and harmonic voltage conditions were established.The simulation testified that this method can eliminate not only the interference of the inter-phase coupling capacitance but also the third harmonic voltage of MOA.Through this method,we can judge the performance of MOA more reliably.更多还原