Numerical Computation of Temperature Rise of Gas‐Insulated Transmission Lines Considering Thermal Properties of Insulating Gas

Accurate temperature rise prediction of the gas‐insulated transmission lines (GIL) can help to lower the cost of equipment through optimization design. To investigate the temperature rise of GIL and the heat transfer efficiency of new eco‐friendly insulating gas, the electromagnetic‐thermal‐fluid field coupling method that considers the thermal properties of solid and gaseous media is proposed. The finite element method is applied to solve the eddy‐current field and obtain the Joule loss of the conductive rod and the enclosure accurately. The GIL temperature distribution of different insulating gases is computed based on their thermophysical parameters. The heat transfer efficiency is found to be positively correlated with gas density, constant pressure heat capacity and thermal conductivity. A parameter that characterizes the heat transfer efficiency of the insulating gas is defined, such that a larger value indicates a higher heat transfer efficiency. This parameter helps to quickly determine the heat transfer capacity of new eco‐friendly insulating gas, and facilitate the optimal design of GIL equipment. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.