Overvoltage characteristics of typical single bus, double bus and one and a half bus GIS configurations under transient SFO, FFO and VFTO conditions are studied. The transient conditions are simulated through load rejections, lightning and the opening and closing of circuit breakers or disconnectors. Surge impedance and travel time are used for defining the distributed parameter models of the GIS. The results suggest that for VFTOs the magnitude of the generated overvoltage solely depends on the switching sequences while for SFOs and FFOs the overvoltage depends on the degree of the inductive load and the type and length of transmission lines.
Nouri, H., Kim, J., & Czumbil, L. (2015, June). Investigation into transient SFO, FFO, VFTO overvoltage characteristics for typical gas insulated substations. Paper presented at International Conference on Power Systems Transient (IPST)