The insulation aging behavior of high frequency electrical equipment can be affected by multiple factors. In order to figure out the influence degree of different factors and their interactions

insulation life of polyimide film was studied based on orthogonal experimental design. High frequency sinusoidal voltage and sphere-to-plane electrode were used

and the designed ranges of frequency

amplitude and ambient temperature were 5～30 kHz

1.5～3.0 k V

and 13～180 ℃

respectively. The influences of these three factors on lifetime and their interactions were discussed based on range analysis

variance analysis

and relation graph. Also

the effects of factor level variation on tolerance coefficients to electrical and thermal stresses were analyzed

as well as the influence on synergistic action of three factors. Results indicate that accelerated effects of frequency and amplitude on insulation aging are similar

which are much larger than that of temperature. Besides

the interaction between frequency and amplitude is the largest

followed by that between amplitude and temperature

and that between frequency and temperature. Interactions between three factors cause the decrease of endurance coefficient to a certain factor with the improvement of other factor levels

and consequent the mitigation of the joint effect of coexisting multi-factors. The method described here provides a new way to study aging behavior of insulation material under the coupling effect of multi-factors.