Effect of Lightning Impulse Voltage on the Performance of 1-phase Gas Insulated Busduct in the Presence of Metallic Particle Contamination with Sf6/n2 Gas Mixtures

SF6 is the main mode of insulation in a GIS. However, in recent years, the future use of SF6 has been debated throughout the world in spite of it having all the desirable properties of a good insulating and arc quenching medium. Sulfur hexafluoride (SF6) has been used as a gaseous dielectric (insulator) in high voltage equipment since the 1950s. It is now known that SF6 is a potent greenhouse warming gas with one of the highest global warming potentials (GWP) known. In the presence of metallic contamination can seriously reduce the insulation performance of a GIS. Particularly the influence of free metallic particles has been regarded as an important issue for many years, since free particles are considered to be hazardous because of the possibility of initiating a voltage breakdown. Transient over voltages due to lightning voltages cause steep build up of voltage on transmission lines and other electrical apparatus. Therefore GIS must be able to withstand such voltages without breakdown of insulation. As GIS operates under power frequency voltages. Lightning impulse voltage of 1050kV superimposed on power frequency voltages of 75kV,120kV and 132kV are applied to 1-Ф GIB and the maximum movement of Cu, Al and Silver contaminants are obtained with and without Monte-Carlo technique for SF6 gas SF6/N2 gas mixtures as dielectric medium.