VFTO对电力变压器绕组暂态电压分布的影响研究

Study of the Transient Voltage Distribution of the Transformer Windings Caused by VFTO

当气体绝缘金属封闭式开关装置（GIS）进行隔离开关分合闸操作时,产生的快速暂态过电压（VFTO）极有可能造成GIS内部设备及与之相连的电力设备发生绝缘事故,其中对电力变压器的危害更为严重。本文应用EMTP对GIS中隔离开关操作引起的各节点的VFTO进行了仿真计算,分析了VFTO的幅值特征,将VFTO作用在变压器绕组上,分析了变压器绕组的暂态电压分布、找出了变压器绕组的绝缘薄弱环节。

The very fast transient overvoltage（VFTO） generated by disconnector operation in gas insulated switchgear（GIS） can cause insulation faults of GIS equipment and electrical equipment connector to it, especially power transformer. In this paper, VFTO at representative position caused by disconnected operation in GIS is calculated and simulated with EMTP, and the characteristic amplitude values of VFTO are analyzed, the VFTO is applied to the transformer windings, and the transient voltage distribution of the transformer windings is analyzed, the potential gradient between the coils and the turns is obtained, the insulation faults of the transformer windings are found, which is in the forward end of the transformer windings.