Influence of Operating Environment on the Aging Characteristics of Composite Insulators

Composite insulators are widely used in power transmission lines due to the excellent electrical properties. However, the aging effect of composite insulators can be observed after a long-term operation under the influence of various factors. In this paper, the aging characteristics of composite insulators operating for 10 years in different environments of Maanshan are studied. The surface physical and chemical properties of composite insulators are evaluated by the water contact angle, surface roughness, surface morphology, infrared spectrum and X-ray photoelectron spectroscopy, while the electrical properties are characterized by the flashover voltage, dielectric characteristics, and trap characteristics. The difference of composite insulator properties under different environment are compared. The results showed that the water contact angle and surface roughness of the aged insulators increased, and the chemical compositions are changed, resulting in the electrical performance degradation. However, the aging states of composite insulators in different environment are different. The performances of insulators operating near a steel plant with serious industrial pollution degrade obviously, while the performances of insulators operating near a closed mine pit after ecological restoration are still relatively good.