Multiphysics Modeling for Transient Analysis of Gas-Insulated Lines

In this paper, two discretization techniques are combined to present a coupled electro-thermal model for the transient analysis of gas-insulated transmission lines (GILs). The analysis of the thermal problem is based on the volume-element-method, representing heat transfer equations on a 2-D axisymmetric GIL model and determining temperature distribution over space and time. For the electrical formulation, the finite-difference time-domain method is adopted considering constant parameters calculated at the frequency of interest. The coupled electro-thermal problem in the case of transient conditions is solved by means of a bidirectional procedure. A set of test cases is imposed on the electric part, and transient analysis is conducted while considering the line coupled electro-thermal performance.