Abstract
The flashover characteristics of the polymer insulator and the effects of a small cavity on the discharge column are investigated. It is observed that the cavity had no noticeable effect on the flashover phenomenon under positive polarity. On the other hand, for negative polarity there seems to be a relationship between the flashover voltage and the needle electrode position away from the cavity opening. It is confirmed that the cavity near high voltage electrode decreases the flashover voltage with negative polarity application.
