Stationary thermal field in the direct current gas-insulated line

The paper has analyzed a stationary thermal field in a direct current gas -insulated line (DC GIL ). After assuming some simplifications, a mathematical model for the system is the boundary problem of the Poisson equation. The conditions of continuity of temperature and heat flux increments were assumed at the boundaries of material layers. The cooling of the system was modelled using Hankel's condition (of the 3rd kind) with the total heat transfer coefficient (i.e. with the sum of the convective and the radiation coefficients ). The problem was solved analytically. After tabulating the formulas, the respective distributions were shown graphically. Additionally, the steady-state current rating was determined. The obtained results have a very good physical interpretation.