Simulation study on steady-state temperature rise distribution of helical spring contact based on electric-thermo-mechanical coupling

Abstract

Thermal failures of busbar gas chambers in gas-insulated metal-enclosed switches (GIS) are common, and the failure points are usually the internal spring contacts. To study this phenomenon in depth, this paper constructs a 3D electrical-thermal-mechanical coupling simulation model of spring contacts, calculates the contact resistance and contact thermal resistance of the spring contact fingers by the Cooper-Mikic-Yovanovich (CMY) theory, investigates the distribution of temperature rise by considering the gravity of conducting rods, and performs thermal-fluid coupling simulation by the real circuit breaker model. The simulation results are consistent with the general characteristics of thermal failure of busbar spring contact fingers. This paper is of great significance for the investigation and analysis of the thermal failure of busbar gas chamber spring contact fingers and their structural optimization design.