Study on Mechanical Characteristics of GIL Three Post Insulator Under Different Loads

Stress concentration will cause mechanical strength deterioration of three-post insulators in GIL, which may threaten the safe and stable operation of GIL. In this paper, the simulation model of a 550 kV GIL three-post insulator is established, and the stress and strain simulation of three post insulator under horizontal and vertical installation conditions are carried out. The stress and strain development laws of the insulator under different radial pressures and axial tensions are studied. The results show that the maximum radial pressure is 9197.1 N in horizontal installation and 2975.2 N in vertical installation. Regardless of the loading mode, the maximum stress of the insulator is at the interface between the epoxy and the grounding insert. With the in-crease of load, the maximum stress and strain of the three-post insulator increase linearly.