An Approach to Determine the Health Index of Power Transformers

This paper describes a realistic health index formulation method for power transformers using readily available data. The method considers practical limitations on obtaining data, and the possible constraints on the parameters. It also utilizes IEC, IEEE, and CIGRE criteria for condition parameters. This Health Index calculation considers not only typical test results such as dissolved gas analysis (DGA), oil quality, furan, and power factor, but also other parameters such as tap changer and bushing condition, physical observations, load history, maintenance work orders, and age. The calculation includes condition ratings, weighting factors, and assigned scores for specific condition parameters. By using a multi-criteria analysis approach, the method combines the various factors into a condition-based health index.