一起110 kV母差保护误动事件分析及改进 

黄杨明，任欣元，莫靖，李强 
广东电网公司佛山供电局，广东 佛山 528000 
 

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。
关键词：母差保护；CT饱和；误动；波形识别；非周期分量
中图分类号：TM773 文献标识码：B 文章编号：1007-3175(2013)02-0027-04

Analysis and Improvement of 110 kV Busbar Differential Protection Misoperation Accident 

HUANG Yang-ming, REN Xin-yuan, MO Jing, LI Qiang 
Foshan Power Supply Bureau, Guangdong Power Grid Corp, Foshan 528000, China 
 

Abstract: 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.
Key words: busbar differential protection; current transformer saturation; misoperation; waveform identification; aperiodic component

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