Assessment of High Voltage Power Transformer Aging Condition Based on Health Index Value Considering Its Apparent and Actual Age

Power transformer takes an important place in the electrical delivery system. This equipment has to maintain its reliability and performance in order to provide good electricity. Power transformer is expected to be operated around 20-40 years. However, sometimes power transformer may fail before it should be. This event may be due to accelerated aging experienced by the equipment. This paper proposes a method to identify the 150 kV transformer aging condition by considering its apparent age based on its health index value. From the health index analysis of 130 power transformers included in the regression model, a linear graph which represent the health index decrease of the population were obtained, with correlation coefficient of R2 0.713. The proposed graph then be used to calculate the apparent age and aging condition of the transformer. This method could help the asset manager to take suitable action to maintain the transformer reliability and performance.