摘要
20 Hz注入式100%定子接地保护在大型发电机保护中得到广泛应用,用于计算接地电阻的20 Hz电压和20 Hz电流信号回路若发生任何故障,将会影响保护动作,因此设置了电压回路监视值和电流回路监视值,一旦发现回路有任何故障,保护装置将闭锁对接地电阻的计算。但是继电保护整定导则未阐述关于这两个监视门槛定值的整定要求,不利于现场的保护整定。针对此,根据某大型水电厂电压门槛值引起注入式100%定子接地保护装置告警的实例分析,建立滤波器输出电压与外部回路电阻之间的表达式,探讨这2个监视门槛值对保护动作的影响及整定方法。
20 Hz injection 100% stator ground protection is widely used in large-scale generator protection, but any faults in 20 Hz voltage signal circuit and 20 Hz current signal circuit used for calculating ground resistance will affect protection. Thus, monitoring values of the voltage circuit and current circuit are set. Once there are any faults in circuits, the protection device will stop calculating ground resistance. In allusion to the problem of lack of setting requirements for these two monitoring threshold setting values in relay protection setting guide rules, that is against to field protection setting, this paper analyzes an actual example of injection 100% stator ground protection device alarming caused by voltage threshold value in one large-scale hydropower plant and builds an expression between output voltage of the filter and external circuit resistance so as to discuss influence of these two monitoring threshold values and corresponding setting method.
出处
《广东电力》
2017年第6期86-89,共4页
Guangdong Electric Power
关键词
定子接地保护
监视门槛值
定值
stator ground protection
monitoring threshold value
setting value
