电流互感器二次回路中性线断线的动模试验研究  

Dynamic Simulation Test on Neutral Line Disconnection ofSecondary Circuit of Current Transformer

作　　者：李蕾 周鹏鹏 李志勇 索江镭 LI Lei;ZHOU Pengpeng;LI Zhiyong;SUO Jianglei(Xuchang KETOP Testing Research Institute Co.,Ltd.,Xuchang,Henan 461000,China;Electric Power Dispatching Control Center of Guangdong Power Grid Co.,Ltd.,Guangzhou,Guangdong 510600,China)

机构地区：[1]许昌开普检测研究院股份有限公司,河南许昌461000 [2]广东电网有限责任公司电力调度控制中心,广东广州510600

出　　处：《广东电力》2022年第3期88-98,共11页Guangdong Electric Power

基　　金：国家重点研发计划基金项目(2016YFB0900600)。

摘　　要：为了分析电流互感器二次回路中性线断线对故障后二次电流及保护动作行为的影响,进行电流互感器二次回路中性线断线的动模试验研究。首先分析三相电流互感器二次回路中性线断线后的等效电路及电流回路,然后在MATLAB/Simulink上建立三相电流互感器模型,通过以MATLAB/Simulink作为仿真模型开发手段的新型实时数字仿真继电保护测试系统建立110 kV线路保护动模试验测试实例,进行电流互感器二次回路中性线断线后的相关动模试验。试验结果表明,电流互感器二次回路中性线断线后,差动保护在发生区外单相及两相接地短路故障时容易误动,接地距离保护在发生区内单相及两相接地短路故障时容易拒动。对电流特征和阻抗特征的分析结果印证了试验结果的正确性。最后,提出保护逻辑改进方案,并通过仿真验证了改进逻辑的可行性。To study the impact of neutral line disconnection in the secondary circuit of current transformer on the secondary current and protection action after the fault,the dynamic simulation test is carried out.This paper firstly analyzes the equivalent circuit and current loop after neutral line disconnection in the secondary circuit of three-phase current transformer,and then establishes the three-phase current transformer model on MATLAB/Simulink.Through the new real-time digital simulation relay protection test system with MATLAB/Simulink as the simulation model development means,it also establishes the dynamic simulation test example of 110 kV line protection for relevant dynamic simulation test after the neutral line disconnection in the secondary circuit of current transformer.The test results show that after the neutral line disconnection,the differential protection is easy to fall into false action in case of external single phase grounding short circuit fault and two-phase grounding short circuit fault,and the grounding distance protection is easy to refuse to operate in case of internal single phase grounding short circuit fault and two-phase grounding short circuit fault.Through the analysis of current characteristics and impedance characteristics,the correctness of the test results is confirmed.Finally,the paper proposes the improvement scheme of protection logic,and verifies its feasibility by simulation.

关 键 词：电流互感器 中性线断线 动模试验 实时数字仿真 继电保护 

分 类 号：TM77[电气工程—电力系统及自动化]