Reduction of Very Fast Transient Over-Voltages in GIS

This paper describes the high voltage transients generated in a 245 KV gas insulated system (GIS). These over voltages are generated due to switching operations and faults. This can lead to breakdown in GIS. Here equivalent circuits have been developed for GIS and very fast transient over-voltages are calculated for fixed and variable arc resistance. These over voltages have been suppressed by inserting a resistor of appropriate value during switching.