Aging Performance Evaluation of Composite Insulators for EHV Transmission Line

In order to timely grasp the operational status of the composite insulators and systematically evaluate the operation stability of the power grid, relevant operating department samples and examines the composite insulators of ultrahigh voltage transmission lines according to the relevant standards in 2016. The test items include material properties, electrical properties and mechanical properties. The test results show that the performance of the composite insulators in the four aspects of the thickness of zinc coating, steep wave impact after boiled, mechanical damage load and end sealing performance did not significantly deteriorate with the increase of operating years; the aging performance of composite insulators mainly reflected in hydrophobicity, sheath core rod water diffusion, umbrella skirt creepage, core rod sheath adhesion of these four aspects, and the degree of aging performance and insulator operating years there is a certain positive correlation.