What is the estimation of elapsed life of oil-immersed power transformers?

The estimation of elapsed life of oil-immersed power transformers typically involves assessing the condition of the transformer oil, including factors such as moisture content, acidity, and dissolved gases. These parameters can indicate the degradation of the oil and insulation system. Generally, the lifespan of oil-immersed power transformers can range from 20 to 40 years, but regular monitoring and maintenance can extend their operational life significantly.