With the action of gravity

moisture accumulates in the tail of the bushing when the bushing is damp. In order to study the influence of moisture on electric field and thermal field distribution of oil-immersed bushing

a simulation model of 110kV oil- immersed bushing was established

and the electric field and temperature field distribution of bushing under different damp conditions were obtained. The results show that the electric field intensity and temperature in the bushing increase when the bushing is damp. The maximum electric field strength increases linearly with wetting height of oil-impregnated paper

and the higher the moisture content is

the greater the increase of the maximum electric field intensity with the wetting height of oil-impregnated paper. On the whole

the maximum electric field strength isn significantly increased after bushing wetted. When the moisture content in oil-immersed paper is less than 4%

the maximum temperature in the bushing changes linearly with wetting height of insulating paper; when the moisture content is 5%

the maximum temperature in the bushing increases exponentially with wetting height of oil-impregnated paper. The temperature rises seriously under damp conditions

which is the main reason for the discharge and damage of bushing.