Aiming at the aging of transformer oil-paper insulation under multiple external environmental factors of electric field

temperature

and mechanical force

this work analyzes the effects of the three factors of electro-thermal force on the life of oilpaper.By conducting accelerated aging tests at different temperatures(363 K

383 K

403 K)

electric field strengths(2 kV/mm

2.5 kV/mm

and 3 kV/mm)

and mechanical stresses(1 MPa

1.5 MPa

and 2 MPa)

the degree of polymerization(DP)of oil-paper insulations at different aging stages is determined

and the loss curves of the degree of polymerization with the change of time are obtained.Based on the time-temperature superimposed method

the temperature leveling factor is improved

and electric field strength and mechanical stress leveling factors are introduced.The effects of the electric field and mechanical force are incorporated into the activation energy term in the Arrhenius equation

resulting in the life assessment model of oilpaper insulation considering multiple factors of electricity

heat

and force.The results provide theoretical support for the life prediction of transformer oil-paper insulation in complex environments.