Under the action of environmental factors, organic materials will undergo various physical and chemical changes, deteriorating their performance. The combined effect of electric field, mechanical load and environmental factors will further aggravate the degradation process. Studies have shown that surface discharge and corona discharge caused by ultraviolet rays, acid rain and pollution under humid conditions are the main factors affecting the aging of the outer insulating material of composite insulators, and the effect of surface discharge is the most significant.
During operation, the umbrella skirt sheath material of composite insulators will show different degrees of aging, such as reduced hydrophobicity, tracking or electrical corrosion, cracking, cracking, chalking, and fading. In fact, some changes in the sheath material of the umbrella skirt do not hinder the continued use of composite insulators, such as the color of the composite insulators; other deterioration phenomena will not threaten the safe operation of the insulators for a long time, such as chalking and change hard.