【摘要】 在常规变电站的数字化改造过程中,可能存在电磁型CT与电子式电流互感器(electronic current transformer,ECT)混合使用于主变差动保护的情况,而电磁型CT与ECT的传变特性差别较大,目前国内尚缺乏对其继电保护适应性的相关研究。为此在EMTDC/PSCAD中分别对电磁型CT、罗氏线圈ECT、全光纤电子式电流互感器(fiber optical currenttransformer,FOCT)进行了建模,采用多种不同的CT混合使用方案,对变压器差动保护区外故障进行了仿真分析,观察比较其对差动保护的影响。仿真结果表明电磁型CT与ECT混合使用一般会使差流增大,若混合使用的电磁型CT性能校验合格,则能保证差动保护不误动。更多还原

【Abstract】 In the digitization renovation of conventional substations,there may be such a circumstance that the electromagnetic current transformers(CT) are mixedly applied to power transformer differential protection with electronic(ECT).There are evident differences in signal transducing and transmission by electromagnetic CT and ECT,and domestic research on the adaptability of mixed application of electromagnetic CT with ECT to relay protection is still not reported.For this reason,the modeling of electromagnetic CT,ECT with Rogowski coil and fiber optical current transformer(FOCT) is performed on EMTDC/PSCAD platform,and simulation analysis on fault occurred outside the protection zone of power transformer differential protection is carried out by mixed application schemes of various kinds of CT,and the impacts of these schemes on differential protection are observed and compared.Simulation results show that in general the mixed application of electromagnetic CT with ECT makes the differential current increased;if the performances of electromagnetic CT could pass through the examination,the malfunction of differential protection would not occur.更多还原