开口式电流互感器铁心质量检测系统的设计与应用

针对开口式电流互感器(CT)因恶劣环境造成内部铁心质量发生变化(如锈蚀等),不能准确反映被测装置一次侧电流,引起差动保护装置的误判,影响检测线路的正常使用这一问题,通过对开口式CT铁心磁化曲线展开研究,以铁心磁化曲线偏离程度作为判定铁心质量优劣的依据;借助硬件搭建一套高精度检测电路,基于上位机软件LabVIEW显示、保存铁心磁化曲线,分析判定不同类型CT的铁心质量.测试结果表明:该系统在不拆卸CT情况下,可以根据铁心磁化曲线的偏离程度判定铁心质量优劣,为差动保护装置的正确工作提供依据,对电力系统的检修及故障预警有着重要意义.

Design and Application of Open Type Current Transformer Core Quality Inspection System

The open type current transformer (CT) lead to the changes of internal core quality (such as corrosion) because of bad environment,which can not accurately reflect the current of measured device side,cause misjudgment of the differential protection device,and affect the normal use of the detection circuit.In order to solve this problem,through the research of open type CT curve of magnetization,the deviation degree of the magnetization curve was used as the criterion of the quality of the core.A set of high precision detection circuit was set up with hardware.The magnetization curve of the iron core was displayed and saved based on LabVIEW software,and the different types of CT core quality was analyzed and determined.The test results show that the system can judge the core quality according to the deviation of the magnetization curve without removing CT and provide the basis for the correct operation of the differential protection device,which is of great significance to the repair and fault alarm of the power system.