The characteristics of creepage discharge in paper-oil insulation（POI） was seriously influenced by the coupling effect of temperature and electrical field in converter transformer.However

few studies have focussed on effect of creepage discharge on temperature in POI under combined AC-DC voltage conditions.Thus

we investigated the characteristic spectra of creepage discharge in POI under combined AC-DC voltage conditions

and explored the mechanism of temperature on characteristics of creepage discharge under different temperaturs of 70 ℃

90 ℃

and 100 ℃ using a cylinder-plane electrode configuration.The experimental results show that the interval time between two discharges decreases under same AC-DC voltage stress

whereas the magnitude of discharges increases with a higher temperature.The developing velocity of creepage discharge is accelerated.Meanwhile

the times of high magnitude discharge（HMD） gradually increases at each stage of creepage discharge with a higher temperature during 4 stages.But the times of low magnitude discharge（LMD） decreases and magnitude of LMD increases.The results indicate that the charge carriers can easily accumulate before discharging and quickly migrate directional movement along the electric field after discharging with higher temperature.The residual charge carriers are dissipated easily after discharging.The ‘hump’ region of LMD moves to the direction of higher discharge magnitude.The HMD intensively appears

resulting in accelerating the development of creepage discharge in POI.