Equipment health rating of power transformers

Transformers are major components of the power delivery system. In North America, a large proportion of them are approaching their end of design life and in need of replacement or refurbishment A program has been developed to assist engineers to diagnose and assess the health of power transformers. The program uses test and inspection data and equipment information such as nameplate, known design problems, operating history, and age to determine the equipment´s health rating. The program calculates condition indexes of transformer components then combines them into an equipment health rating. Although the program automatically calculates such values, it also allows for experts to provide diagnostics and make recommendation on intervention, and to review all the final rating . The results can be used to quickly assess equipment health and provide comparison within a substation or the entire utility for asset management. Examples and case histories are used to show the merits and applications of the program for BC Hydro´s system.