Segunda-feira (26/11/2018) | 15h30 às 16h45 | Auditório
In this tutorial, Mr.Subramany will present an overview of short-circuit stresses on transformers and reactors which are the components most sensitive to short-circuit. He will first present and evaluate failure rates of large power transformers in service, based on CIGRE and EPRI data.
Then, the nature of the large mechanical stresses due to short-circuit current will be analyzed and illustrated with videos from full-power tests.
In the third part, the short-circuit testing of large power transformers, and its standards will be illustrated and discussed with examples. The latest developments in the future IEC 60076-5 standard on short-circuit withstand verification will be highlighted.
In total, around 350 test series were analyzed, showing that 22% of the tests result in a failure initially. Failure to pass short-circuit tests is mainly by winding deformation, reflected in an increase of short-circuit reactance beyond what is accepted in the standard, but several other failure modes are frequently observed, like oil spill, damage to bushing and leads, etc. and are demonstrated by real-time videos.
O workshop será apresentado em inglês e contará com tradução simultânea para a apresentação e interação com o tutor em português.