与ECT混合用于差动保护的电磁型CT的校验方法  

A Verification Method for Electromagnetic Current Transformers Mixedly Applied in Differential Protection With Electronic Current Transformers

作　　者：余祥坤 吕艳萍[2] 杨丽[2] 袁亮[2] 向黎[2] 罗志娟 

机构地区：[1]湖北电力勘测设计院,湖北省武汉市430040 [2]武汉大学电气工程学院,湖北省武汉市430072

出　　处：《电网技术》2012年第10期275-280,共6页Power System Technology

摘　　要：常规变电站的智能化改造过程中,可能存在电磁型CT与电子式电流互感器(electronic current transformer,ECT)混合用于变压器差动保护的情况。变压器区外短路时,由于电磁型CT与ECT的传变特性不同,可能引起差动保护误动,为此提出了与ECT混合用于变压器差动保护的电磁型CT的校验方法。该方法需要根据实际系统和电磁型CT的具体参数进行计算,校验过程中综合考虑了铁心剩磁的影响和保护装置抗饱和措施的要求。校验合格的电磁型CT与ECT混合用于变压器差动保护,即使在最严重的外部故障情况下,也能保证差动保护动作的可靠性。EMTDC/PSCAD仿真结果验证了该校验方法的有效性。During the smartness upgrade of conventional substations,such a circumstance may exist that electromagnetic current transformers（CT） are mixedly applied in transformer differential protection with electronic current transformers（ECT）.When short-circuit fault occurs outside the transformer protection zone,due to the differences between the transformation and transmission characteristics of electromagnetic CT and those of ECT,the malfunction of transformer differential protection might be caused.For this reason,a verification method for electromagnetic CT mixedly applied in transformer differential protection with ECT is proposed.In the proposed method the computation based on concrete parameters of the actual system and electromagnetic CT should be performed,and during the verification the impact of the core and the requirement to anti-saturation measures of protection device are synthetically considered.The mixed-application of electromagnetic CT passed the verification with ECT in transformer differential protection can ensure the action reliability of the differential protection even though under the occurrence of the most serious external fault.Results of EMTDC/PSCAD-based simulation verify the effectiveness of the proposed verification method.

关 键 词：电磁型电流互感器 电子式电流互感器 混合使用校验 变压器差动保护 

分 类 号：TM45[电气工程—电器] TM734