Comparison Study of Insulation Performance of Semiconducting Glaze, Ceramic, and Glass Outdoor Insulators with Artificial Conditions.

Ceramic and glass insulators as the first generation of insulators are often affected by flashover disturbance during operation. Ceramic insulators coated with semiconducting glaze (SCG) material are then proposed to improve the insulation performance due to warmer surface characteristics that can trigger evaporation on the surface. In this paper, a comparison of insulation performances of semiconducting glaze, ceramic, and glass insulators is discussed from both electrical and non-electrical aspects under various conditions. This comparison aims to distinguish the leakage current characteristics of each insulator during operation. Leakage current tests are conducted to obtain leakage current characteristics of each insulator under artificial conditions of no fog, clean fog, and salt fog. Furthermore, pollutants that are a mixture of NaCl (as equivalent salt deposit density (ESDD)) and kaolin (as non-soluble deposit density (NSDD)) are sprayed onto the insulator surface to see how the pollutant affects the leakage current characteristics of each insulator. The properties of measured leakage current waves are then analyzed, including the waveform, magnitude, and harmonic components. In addition, the non-electrical tests consist of hydrophobicity tests and thermal tests. In the hydrophobicity test, the contact angle formed by a water droplet on the insulator surface is measured, and in the thermal test, temperature differences on the insulator surface before and after voltage applications are compared. The experiment results show that the SCG insulator has a larger leakage current than the other insulators, while the leakage current magnitude of the ceramic and glass insulators is similar. The surface temperature of the SCG insulator is also higher than that of the other insulators due to a larger leakage current. Additionally, the SCG insulator shows better hydrophobicity compared to the other insulators, where all types of insulators show decreased contact angle when pollutants are given. [ABSTRACT FROM AUTHOR]