Research on Steady‐State Thermal Behavior of SF6/N2 and CF3I/N2 Mixtures in High Voltage Gas‐Insulated Lines (GIL)

Abstract

Gas‐insulated lines (GIL) are widely used due to their many advantages in power plants and substations. The security and reliability of GIL is achieved by continues testing and monitoring. The main fault in the GIL compartments is overheating, which is rarely to occur, nonetheless, it cannot be ignored. In the present study, GIL steady‐state thermal behavior was investigated. For this reason, a multiphysics finite element model (FEM) was built to analyze the magneto‐hydro‐thermal characteristics of the GIL insulation gas. The simulation coupling includes the electromagnetic field, flow field and thermal heat transfer field. SF6/N2 and CF3I/N2 mixtures were studied and the influence of different gas properties on the magnetic flux density, heat distribution and flow velocity had been investigated. The results were compared to an experimental setup to validate the model calculations. Temperature rise tests have been conducted on the GIL inner and outer shell. The measurements were in good agreement with the simulation results. Finally, the presented work is also to serve as a good reference in future design and optimization of GIL structure. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.