Study of aluminium contaminants of different dimensions in a single phase gas insulated busduct

Gas insulated substations have found their applications in the modern day power industry due to their low space requirement and higher reliability of operation. Their major components include busducts, circuit breakers, transformers that are placed in enclosures filled with sulphur hexafluoride gas. The major component of GIS is the gas insulated busduct which has conductors enclosed in an earthed metallic enclosure filled with a high electronegative gas sulphur hexafluoride, SF₆. Though GIS are highly reliable, the major reason for the breakdown is due to the metallic particle contamination which arises due to manufacturing and operational functions. Among the contaminants, Aluminium particles are of prime concern as they are lighter and hence move freely when compared to the other metallic particle contaminants.In this paper, the critical dimensions of Aluminium wire like particle contaminants are determined which may lead to breakdown using the conventional field calculation method. The simulation results show that the particles with higher lengths and with lower radii are more responsible for breakdown in busducts.