发电机匝间保护与负序功率方向元件

Turn-to-turn Faults in Stator Windings of Generator and Negative Power Directional Unit

在采用纵向零序电压的方式来反映发电机的匝间短路故障时,为防止电压互感器(TV)断线误动作,采用TV断线闭锁逻辑。然而由于某些保护制造厂逻辑功能软件的不严密,在发电机TV一次断线时,匝间保护时常发生误动作。提出增加用负序功率方向元件来进行判断内外部故障,可以有效防止匝间保护误动作。

Mostly in the existing projects,longitudinal type neutral overvoltage relaying to against turn-to-turn faults in stator windings is provided. For PT fuse failure,blocking logic is provided. However,in fact,as the logic scheme of relay manufacturer is not so strict that turn-to-turn faults protection fi＇equently maloperate. To prevent this maloperation, negative power directional unit can be used for judging the fault between internal and external, which is a way to prevent turn-to-turn faults protection maloperation.