Research and simulation analysis of crack failure mechanism of conductor spacer bar in ±800 kV converter station

Abstract

The cracking of the conductor spacer bar in a ±800 kV converter station was detected and simulated to study the cause of failure. By means of penetration detection, fracture macroscopic inspection and metallographic inspection, it can be found that there are some casting defects such as segregation, pinhole and intergranular micro-crack in the chuck microstructure of the spacer bar, and the fatigue fracture occurs under the action of alternating stress. Through the structural simulation analysis, it can be concluded that the spacer rod body and the joint of the chuck have a structural mutation, which causes stress concentration and leads to the fracture of the spacer rod. Finally, suggestions are put forward to improve the design, manufacture and installation process of spacer rods to prevent similar failures from happening again and ensure the safe operation of the power grid.