Transient Enclosure Voltage (TEV) Modeling in GIS Substations

Due to space limitation along with the necessity to the increase of the substations, gas insulated substations (GISs) have been favorable option owing to their minimum required space for installation. One of the main challenge in this substation is very fast transient overvoltage (VFTO) giving rise to the operation of disconnector. These waves travel through various components. Interestingly, along with waves, a wave is inducted on the ducts called transient enclosure voltage (TEV) or transient ground potential rise (TGPR). This paper has been devoted to investigate these waves through modeling GIS and presenting some analytical approach. Subsequently, the impact of GIS design, CVT, arrester, and ground strap have been discussed through simulations in EMTP-RV. Finally, the impact of high frequency ground behavior has been discussed to show the importance of the design of grounding system in GISs from high frequency point of view.