GIS Electrical Contact Characteristics Simulation Based on Electric-Magnetic-Force Coupling

Gas insulated switchgear (GIS) is difficult to observe because of its closed and compact structure. Therefore, the study of GIS touch electrode electrical contact characteristics becomes significantly more challenging. The article is based on the coupling of electric field, magnetic field, and structural mechanics. Calculate the magnetic field strength of GIS, and based on the simulation of structural field, establish a three-dimensional simulation model of moving and static contacts, thus obtaining the influencing conditions on the electrical contact characteristics of GIS contacts. The factors affecting electrical contact of GIS contacts include radial deformation, contact pressure and bending stress of contact fingers. The results show that: the magnetic field strength dominated by the outer diameter of the conductor is significantly greater than the magnetic field strength inside the pipe, and the direction of the magnetic vector is along the tangent of the outer diameter of the conductor. The current and the magnetic field are concentrated on the inner surface, with the magnetic induction intensity inside the shell being higher than that outside the shell. Based on the relationship between contact pressure and contact resistance, the calculation of factors affecting the electrical contact of GIS contacts is carried out. According to the theory of electrical contact, each contact finger in the circuit is in a parallel relationship, which allows the determination of the contact resistance. Through the contact resistance, the electrical contact state of the GIS contacts can be identified.