摘要
变压器和应涌流在电流互感器饱和时,会因为差动电流二次谐波比低于定值而导致保护误动,以及和应涌流闭锁期间发生内部短路故障时,差动电流二次谐波比依旧高于定值而导致保护拒动。鉴于上述问题,该文在现有二次谐波制动方案的基础上,通过构建差动电流相位差的附加判据,以此对差动保护的工作模式加以优化,借助PSCAD/EMTDC对该附加判据进行了仿真验证,结果表明,所提方案效果明显,可以应用于和应涌流的识别及其与内部故障的区分。
When the transformer and the sympathetic inrush current are saturated,the differential current second harmonic ratio is lower than the fixed value,resulting in the protection misoperation;and when the internal short circuit fault occurs during the period of the sympathetic inrush current locking,the differential current second harmonic ratio is still higher than the fixed value,resulting in the refusal of protection.To this end,on the basis of the existing second harmonic brake,this article optimizes the operation mode of the differential protection by building additional criterion of current differential phase,in order to optimize the operation mode of the differential protection,and with the help of PSCAD/EMTDC,the simulation verification of the operation is carried out and the results show that the proposed scheme is effective and can be applied to the identification of sympathetic inrush current and internal fault.
作者
栗磊
梁亚波
赫嘉楠
熊军辉
满在领
郝治国
LI Lei;LIANG Yabo;HE Jianan;XIONG Junhui;MAN Zailing;HAO Zhiguo(State Grid Ningxia Electric Power Research Institute,Yinchuan 750001,Ningxia,China;School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,Shaanxi,China)
出处
《电网与清洁能源》
CSCD
北大核心
2023年第8期64-72,共9页
Power System and Clean Energy
基金
宁夏自然科学基金项目(2020AAC03484)
国网宁夏电力有限公司科技项目(5229DK190055)。
关键词
和应涌流
差动保护
二次谐波制动
内部故障
相位差
sympathetic inrush current
differential protection
second harmonic braking
internal failure
phase difference
作者简介
栗磊(1982-),男,硕士,高级工程师,研究方向为变压器状态评估及故障诊断技术。
