Aging of composite insulators: simulation by electrical tests

To assess the long term performance of 72 kV and 230 kV composite long rod insulators, different laboratory aging tests have been developed. Two principal diagnostic tests were used to measure the performance of the insulators, the quick flashover salt-fog (QFO SF), and the rapid flashover clean-fog (RFO CF) tests. The following aging processes were used: cement coating and clean-fog, salt fog, and cement coating and salt fog. Similar sets of insulators were also aged in the field for over three years, and all the insulators were evaluated in the laboratory. The cement/salt-fog aging process was found to be the most controllable and realistic after the results were assessed by means of the RFO CF test.<
>