Effect of uneven wetting on E-field distribution along composite insulators

The aim of this paper is to study the influence of uneven wetting conditions on the E-field distribution and leakage current along composite insulators under dense cold fog. The tests were carried out in an environmental chamber to simulate natural climate conditions. In the experimental investigation two conditions were considered: the presence of uniform contamination levels and uneven wetting pattern of that contamination under cold fog along insulator surface. The changes in the E-field distribution with uneven wetting on the insulator surface were measured with a spherical probe and field meter. For the E-field distribution, the probe was moved parallel to the axis of the composite insulator. The obtained results suggest that the E-field distribution based on uneven wetting can be an effective tool to evaluate the performance of composite insulators.