Influence of power source on contamination withstand voltage of polymer insulators

In general, heavy leakage currents flow on contaminated and wetted insulator surfaces, and so it is specified to evaluate the contamination withstand voltage performance of ceramic insulators in laboratory using a power source stiff enough to avoid a voltage drop. However, it has not been confirmed whether such a requirement is also necessary for hydrophobic polymer insulators considering the relatively smaller magnitude of leakage currents on such hydrophobic insulators. The authors made comparative contamination tests on hydrophobic polymer insulators by a stiff and a weak power sources to evaluate the influence of stiffness of power source on contamination withstand voltage performance of hydrophobic polymer insulators. For reference, porcelain suspension insulator units were also evaluated by these power sources