Analysis Of Particle Contamination In Gas Insulated Busducts Operating On High AC Voltages

Abstract

The high reliability and safety provided by the compressed gas insulated substations(CGIS) has proved that the they are more advantageous than the conventional air insulated substations. All the parts of the GIS are enclosed in metal enclosures which are filled with SF₆ gas, which has higher breakdown strength than air. Although superior by the performance, the metallic particle contamination greatly hinders the electrical insulation performance of the Gas insulated substations. The free conducting particles, which arise from the parts of the GIS, are commonly found on the enclosure. They move randomly and on crossing the inter electrode gap and sticking to the inner electrode, they lower the breakdown voltage of GIS. In the present work, the movement of the commonly encountered aluminium and copper wire type metallic particle contaminants of different dimensions, in a single phase gas insulated busduct, are determined, operating under various AC voltages. The simulation results are presented and analysed.