CAJ | 학술논문

分析了某220 kV变电站发生的一起110 kV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3~4 ms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.
분석료모220 kV변전참발생적일기110 kV모차보호오동사건,득출료본차오동적근본원인재우외부고장절제후,모차보호립각퇴출전류파형식별폐쇄판거저일라집결함.고필도전류재전류호감기(CT)포화후매일과영점도유일단3~4 ms진실전변구,제출과영점중계파형식별판거,직도파형식별출CT포화소실,이해결구외고장절제후,재쇠감과정중적비주기분량영향하,모차보호오동문제.
Analysis was made to the accidental operation of a 110 kV busbar differential protection in certain 220 kV substation. The fun-damental reason of the accidental operation was the defective logic that busbar differential protection immediately exited the current wave-form 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.