750 kV变电站GIS设备VFTO特性研究

目前针对特快速暂态过电压（very fast transient overvoltage，VFTO）特性的研究多集中在微观领域，利用已有成果从变电站运行方式等宏观方面对VFTO进行研究具有重要意义。以宁夏沙湖750 kV变电站为例，利用ATP-EMTP仿真软件建立动态电弧模型，详细分析和对比了运行方式及倒闸顺序对VFTO的影响，并对并联电阻抑制VFTO效果进行了校验，仿真结果表明：VFTO幅值不仅与运行方式有关，还与倒闸顺序相关；若仅从幅值角度考虑，VFTO对GIS内部和变压器绕组绝缘并无较大威胁。为750 kV GIS设备研制和变电站运行提供了有益的参考和依据。

Study on VFTO Charaterstics of GIS in 750 kV Substation

The current studies of very fast transient overvoltage(VFTO) in GIS are mostly concentrated in microcosmic aspects and some achievements have been gained. Consequently, it is significant to investigate VFTO characteristics of GIS from macro respect by using existing research results in microcosmic respects. In this paper, by taking the Shahu 750 kV substation in Ningxia as an example, a dynamic arcing model is built with the software ATP-EMTP, and a detailed analysis is made of the effect of operation modes and order on VFTO and the inhibitory effect of shunt resistance on VFTO is checked. The simulation results show that the amplitude of VFTO is not only related to the operation mode but also associated with the operation order. Therefore, the VFTO does not pose a serious threat to the insulation of internal GIS and transformer windings in view of amplitude. The study results can provide a useful reference and basis for 750 kV GIS equipment development and substation operation.