摘要
分析了某220kV变电站发生的一起110kV母差保护误动事件,得出了本次误动的根本原因在于外部故障切除后,母差保护立刻退出电流波形识别闭锁判据这一逻辑缺陷。考虑到电流在电流互感器(CT)饱和后每一过零点都有一段3～4ms真实传变区,提出过零点重启波形识别判据,直到波形识别出CT饱和消失,以解决区外故障切除后,在衰减过程中的非周期分量影响下,母差保护误动问题。
Analysis was made to the accidental operation of a 110 kV busbar differential protection in certain 220 kV substation. The fundamental reason of the accidental operation was the defective logic that busbar differential protection immediately exited the current waveform recognition locking criterion after the removal of external faults. Considering that after the current transformer （CT） saturated in each zero crossing, the current has a 3 to 4 ms real transmission area, this paper put forward that the current waveform recognition criterion was restarted in each zero crossing until the CT saturation disappeared, to solve the problem of busbar differential protection maloperation under the influence of the aperiodic component in the attenuation process after the removal of external faults.
出处
《电工电气》
2013年第2期27-30,共4页
Electrotechnics Electric
关键词
母差保护
CT饱和
误动
波形识别
非周期分量
busbar differential protection
current transformer saturation
misoperation
waveform identification
aperiodic component
