Temperature Rise Prediction of Gas-insulated Transmission Lines Based on Thermal Network Model Considering Contact Fingers

Gas-insulated transmission lines (GIL) requires a small contact resistance and a stable temperature rise that does not exceed the IEC standard. The thermal network model (TNM) has low computational cost with sufficient accuracy and is suitable for fast temperature rise prediction. In this work, a TNM considering the contact finger and shield structure is established. The heat source is obtained by solving the eddy-current field and calculating the ohmic loss. The thermal convection resistance is obtained by integrating the convective heat transfer coefficient on the surface of the component and taking the reciprocal, which reduces the error of traditional method determined by the characteristic size and characteristic temperature. The computation results of TNM are verified through FVM simulations of thermal-fluid field and prototype experiment.