Corrosive Sulphur and DBDS in Transformer Oil: Risk Assessments and Mitigation Actions on Power Transformers and Reactors - Utility Experience

Magdy Abdelsalam Osman Ismail, Ashish George Ellengical, Rohan Dsouza, Mohammed Intekhab Shaikh

Abstract: Research by certain international agencies/ laboratories, following the failure of many high voltage equipment in different parts of the world, have led to the finding that copper sulphide produced by the reaction of DBDS with bare copper/ winding conductor could reduce the dielectric strength of the paper insulation, eventually resulting in breakdown of the equipment. Considering the novelty of the phenomenon and the potential threat imposed on transmission equipment, Dubai Electricity and Water Authority conducted a study to identify & assess the risk to equipment and take necessary actions to mitigate the risk. This paper describes the strategic approach and the results of the study as well as implementation and the current status of the mitigation actions.

Keywords: Corrosive Sulphur, Copper Conductor, Copper Sulphide, Thermal Aging, Oil-paper insulation, Transformer, Reactor, Mitigation, Passivation, Reclamation, Adsorbent, Replacement