PROJECT TITLE :

Breakdown performance of vacuum circuit breakers using alternative CF3I-CO2 insulation gas mixture

ABSTRACT:

During this paper, sulphur hexafluoride (SF6) insulated vacuum interrupter circuit breakers have been used to explore replacing SF6 gas with a trifluoroiodomethane and carbon dioxide (CF3I-CO2) gas mixture. The explore for another insulation gas is driven by the well known extreme international warming potential of SF6. For this purpose, the circuit breaker gas compartment of a bit of gas insulated switchgear (GIS) was stuffed with a CF3I gas mixture and then tested using lightning impulses up to the rated stand up to strength. The tested ring main unit was initially designed to be insulated with SF6 gas. The unit may be a three-section switchgear containing two switches per section; a selector interlock and a vacuum bottle circuit breaker per part. The check programme performed in this investigation demonstrated the breakdown performance and insulation strength of the new gas mixture still as the vacuum circuit breakers behavior when insulated with a new insulation medium. Information on the dielectric properties of the proposed gas mixture is presented, and also the performance of the tested vacuum circuit breaker is mentioned. Promising results are obtained which indicate the suitability of this additional-environmentally friendly gas for top voltage insulation purposes.