摘要
零序CT存在异常影响继电保护装置的正确动作,现有判断零序CT极性接反的方法大多基于故障性质,即无法预防CT极性接反而引起的继电保护不正确动作。建立中压配电网系统简化数学模型,通过分析母线三相补偿电容器组不同时投入引起的暂态零序冲击过程,挖掘其零序电气量与零序CT正确极性的关联特征;基于该关联特征提出基于暂态零序冲击的零序CT极性辨识判据,并利用小波变换模极大值捕捉并计算母线三相补偿电容器组不同时投入时的母线零序电压变化量和各馈线零序电流变化量,结合所提判据对零序CT极性进行辨识;最后采用PSCAD/EMTDC电磁暂态仿真软件搭建中压配电网系统仿真模型,模拟母线三相补偿电容器组投入的不同情况,对所提辨识方法进行验证。
The abnormality of zero sequence CT affects the correct operation of relay protection devices.Most of the existing methods for judging the polarity reversal of zero sequence CT are based on the nature of the fault,which cannot be judged in advance.A simplified mathematical model of the medium voltage distribution network system is established.By analyzing the transient zero sequence impulse process of the three-phase compensation capacitor banks of the bus at different times,the correlation characteristics between the zero sequence electrical quantity and the correct polarity of the zero sequence CT are mined.Based on this correlation feature,a zero sequence CT polarity identification criterion based on transient zero sequence impulse is proposed,and the wavelet transform modulus maxima are used to capture and calculate the bus zero sequence voltage variation and the feeder zero sequence current variation when the three-phase compensation capacitor banks of the bus are not put into operation at the same time,and the zero sequence CT polarity is identified in combination with the judgment.A simulation model of the medium voltage distribution network system is built using PSCAD/EMTDC and different scenarios of the three-phase compensation capacitor banks of the bus is simulated in order to verify the proposed identification method.
作者
王维权
梁柱坚
陈浩泳
梁远升
Wang Weiquan;Liang Zhujian;Chen Haoyong;Liang Yuansheng(Zhaoqing Power Supply Bureau of Guangdong Power Grid Co.,Ltd.,Zhaoqing,Guangdong 526000,China;School of Electric,South China University of Technology,Guangzhou 510640,China)
出处
《机电工程技术》
2024年第5期58-63,99,共7页
Mechanical & Electrical Engineering Technology
基金
2020年依托基建工程技术创新专题“智能变电站”配套技术研究项目(031200WS22200001)。
关键词
零序电流互感器
极性辨识
暂态零序冲击
zero sequence CT
polarity identification
transient zero sequence impulse
