Simulation of VFTO Suppression Methods for 1100kV GIS Substation

Disconnector switch operation in GIS will generate VFTO, which will harm the equipment. Because there are many limitations in field measurement, simulation can overcome the limitations of experimental research, which can replace test measurement to a certain extent. In this paper, three VFTO suppression methods are simulated in ATP-EMTP. By comparing the VETO amplitudes of the main equipment before and after the suppression measures, the results show that the paralleling closing resistor can significantly reduce the VFTO amplitude of major equipment. Simplifying wiring also have better suppression but will increase the VFTO amplitude of some devices.Although installing the wave blocker can reduce the VFTO steepness and amplitude on the transformer, but it will produce a serious VFTO on the wave blocker. So the latter two methods can only be applied when appropriate. Through this research, to find the application of the suppression measures, thus effectively reducing the hazard of the VFTO in GIS.