Simulation Analysis of Internal Defects in GIS Disconnector on Electric Field of Pull Rod

In GIS disconnector, the pull rod acts as an insulating support for connecting current-carrying conductor and shell. It bears large voltage and strong machinery for a long time. During assembly and live operation, the pull rod may be damaged, and various defects appear inside and outside the rod, which affects the stable operation of the GIS. In order to study the defects' influence on the insulation performance of the pull rod, a three-dimensional model of the GIS disconnector was established in this paper. The electric field distribution of the isolating switch under normal operating was calculated by using the finite element software, which can obtain high field strength position of the insulating rod surface. On this basis, the influence of gas defects on the electric field distribution in the pull rod was studied. The comprehensive effect of the position and size of the gas defect on the field strength of the pull rod was analyzed. The results show that the electric field strength caused by gas defects near the high field strength position is higher, even exceeding the maximum field strength of the pull rod. Compared with the defect length parameter, the position parameter of defect is an important factor affecting the electric field of pull rod, which can provide a basis for the manufacture and assembly of the pull rod and improve the safety and stability of the power system.