Comprehensive Method for Determining Transformer Decommissioning Life Considering Economic Life and Physical Life

Accurately calculating the decommissioning life of power transformers is not only helpful for maintaining their operational security and reliability, but also can enhance the economic operation of the power system concerned. This paper proposes a comprehensive method to determine the decommissioning life of power transformers considering both the economic life and physical life. First, according to the Life Cycle Cost (LCC) model of power transformers, a mathematical model of initial cost, operating and maintenance cost, failure cost and disposal cost is established. Then the economic life of power transformers is obtained based on the annual average LCC curve. Secondly, the physical life of power transformers is calculated by first correcting the expected service life with the load factor, temperature factor and humidity factor, and then correcting it with the failure number during operation. Finally, the theoretical decommissioning life of power transformers is attained by comprehensively considering both the economic life and physical life.