Based on the thermal kinetics

the thermal degradation behaviour of K125AX extra-high voltage transformer oil was investigated by thermogravimetric analysis at five different heating rates: 5

10

20

30 and 40 ℃/min respectively. With differential method and integral method

kinetic parameters of the transformer oil were obtained. The results indicate that the decomposition process undergoes a single step. The kinetic parameters available get different from each other under various treating methodologies

while the result with Coats-Redfern method is probably much more reliable with a correlation coefficient approaching to 1

and the activation energy of the transformer oil is 57.48 kJ/mol.The mass loss lifetime equation is determined at mass loss ration of 2% to facilitate the assessment of the lifetime of transformer oil.