为评估特快速暂态过电压（very fast transient overvoltage ，VFTO）特性及其对主要电气设备的危害，结合我国西北电网中某750 kV 气体绝缘金属封闭开关设备（gas-insulated metal-enclosed switchgear，GIS）变电站，进行了大量的仿真计算，初步掌握了GIS 内、外部主要部位VFTO的分布情况，并得出该变电站最大VFTO幅值在相关设备耐受能力范围内的结论。在此计算基础上进行了现场实测，准确掌握了750 kV GIS变电站VFTO实际幅值、波形及频率等重要特性参数。现场实测结果对于750 kV GIS 中隔离开关的倒闸操作具有实际指导意义，同时也为1 000 kV交流特高压GIS设备中VFTO的实测及倒闸操作积累了经验和数据。

In order to evaluate characteristics of VFTO and its harm to the main electrical equipment, we have done a great quantity of emulational calculations integrating with a certain 750kV GIS Substation in Northwest Power Grid of China. In the process, preliminarily, we have mastered the distribution of VFTO on main parts inside and outside of GIS and made a conclusion that the VFTO amplitude limit is in withstand capability of the relative equipment of this substation. We performed measurement on site based on the calculations, mastered important characteristic parameters, such as actual amplitude, wave shape, frequency and so on of VFTO in 750kV GIS substation. The measured results on site have instructive significance for the switching operation of disconnector of 750kV GIS, meanwhile, it made us accumulate valuable experience and data for actual measurement of VFTO and switching operation of UHV 1 100kV GIS.