GIS隔离开关操作对电子式电流互感器的干扰分析及防护

Interference Analysis and Protection of Electronic Current Transformer Caused by Disconnect Switch Operation in GIS

为了给GIS集成式电子式电流互感器的工程设计和安全运行提供理论依据,文中以隔离开关开合造成的VFTO是引起电子式电流互感器受干扰的唯一干扰源和根源的结论,分析建立了四川某工程126 kV GIS内部和外部暂态计算电路。选取变压器间隔GIS典型结构作为分析对象,利用EMTP合理地选择参数并建立了VFTO和TEV仿真计算模型,计算了GIS各主要节点的VFTO和TEV。通过仿真计算及研究结果表明,GIS集成式电子式电流互感器的设计应用是个系统工程,除了要考虑电子式互感器自身的传感器部分和电子电路部分的干扰防护设计,还要考虑GIS的结构布局、母线、壳体尺寸和接地等因素对VFTO的抑制。

In order to provide the theoretical reference for engineering design and safe operation of integrated electronic current transformer （ECT） in GIS, this paper considers that very fast transient overvoltage （VFTO） caused by disconnect switch operation is the only interference source and the root causes of the electronic current transformer with electromagnetic interference. The inside and outside transient circuits of a GIS substation in Sichuan are established by EMTP. The typical structure of the transformer interval GIS is selected as the analysis object and the reasonably parameters are chosen to establish VFTO and TEV simulation model by using EMTP. The VFTO and TEV occurred at main nodes are calculated. The calculation and research results show that the design and application of GIS integrated electronic current transformer is a system engineering. It needs to consider the overall design of GIS, suppression of VFTO in GIS structure layout, buses, the size of the shell and well- earthing and other factors. Besides the interference protection design of the sensor part and the electronic circuit part of electronic current transformer are suggested.