Analysis of Factors Affecting the Performance of O-rings of 110kV Transformer Bushing Conservator

O-ring failure is a primary cause of moisture intrusion in transformer bushings. In order to investigate the failure mechanism of the O-ring and the factors affecting its performance, ABAQUS software is employed to simulate the sealing structure of a typical 110kV bushing conservator. Equivalent stress and contact stress distribution of the O-rings under varying structural parameters and temperatures are botained by simulation and the impact of each influencing factor on sealing performance deterioration are analyzed. Furthermore, a plane seal structure test model is designed, and a thin-film pressure sensor is utilized to measure the contact stress of the sealing surface, thereby the accuracy of the simulation method is verified. The results indicate that the relative error between the test and simulation is within 10%. Additionally, it is found that the compression amount and the contact surface friction factor significantly affect the sealing performance of O-rings. Simulation shows on onehand under normal operation conditions, the temperature distribution of the sealing structure in the bushing conservator is relatively uniform, on the other hand thermal expansion exerting a notable influence on sealing performance. These findings contribute to the identification of key factors leading to the deterioration and failure of bushing O-rings.