Abstract
This paper describes the effect of acetophenone on space charge formation and dc dielectric breakdown in polyethylene film. Impulse electric strength increased in the polarity where carrier injection was much larger in the acetophenone coated film. The increase of impulse electric strength is considered to be due to the homo space charge formed by the carrier injection from acetophenone coated side electrode. With increase of voltage rise rate, dc electric strength increased in the acetophenone coated film. Space charge was formed by the carrier injection from acetophenone or benzene coated side electrode. However the amount of space charge formed in benzene coated film after short-circuiting was smaller than that in acetophenone coated film. The dc electric strength of benzene coated film was almost as same as that of non coated film. From these results, it is considered that the decrease of do electric strength in acetophenone coated film is caused by both thermal breakdown process and accumulation of space charge
