Research on Thermal Stress Distribution of GIS Basin Insulator

Abstract

Basin insulator is an important part of gas insulated metal enclosed switchgear (GIS). Its mechanical performance is not good, which is easy to cause insulation failure, which threatens the safe and stable operation of GIS, and thermal stress is one of the reasons for the deterioration of mechanical performance of basin insulator. In order to study the distribution law of thermal stress and strain of basin insulator, this paper establishes 252 kV GIS basin insulator simulation model by combining simulation and test, and establishes a thermal stress ultrasonic detection system. The distribution law of thermal stress and strain of 252 kV GIS basin insulator is obtained by finite element simulation analysis and stress ultrasonic longitudinal wave reflection detection. The results show that the temperature of the insulator is gradiently distributed along the conductor flange direction when the center conductor is under the temperature load. The thermal stress and the thermal strain decrease gradually along the conductor flange direction, and increase with the increase of the temperature load. The normal ultrasonic propagation time is characterized by normal thermal strain, which is proportional to the temperature load.