Dynamic modeling of temperature rise characteristics reflecting microscopic changes in contact structures of eco-friendly gas-insulated switchgear under electrical wear

Abstract As the global energy transition accelerates, eco-friendly power equipment technology is expected to play a more significant role in emerging power systems. In eco-friendly gas-insulated switchgear (GIS), the interruption of high currents induces electrical wear on internal contacts, leading to surface erosion, oxidation, and the formation of microscopic asperities. These alterations contribute to localized heat accumulation, thereby degrading the thermal performance of the equipment. To address this, a novel temperature rise model is introduced for eco-friendly GIS insulated with dry air, integrating Baharami electrical contact theory with multi-field coupling finite element simulations. This model dynamically reflects the evolving morphological changes in contact surfaces under varying degrees of electrical wear. A detailed analysis of equipment under different operational conditions, with adjustments to parameters such as contact roughness and asperity distribution, simulates the real-time deterioration process of contacts due to electrical wear. Experimental validations indicate that the temperature simulation errors of the model remain within 5 % across most key points, with the model demonstrating favorable solving speed and convergence. Compared to the results obtained using the traditional model, the maximum temperature rise error decreased from 11.3 % to 7.5 %, representing a reduction of 33.6 %. The average temperature error at each measurement point also showed a significant decrease, from 3.48 K to 2.41 K, corresponding to a reduction of 30.7 %. Under severe electrical wear, temperature rises can exceed standard limits, with an accelerated rate of increase as wear progresses, posing risks to equipment reliability. Adjustments to the parameters of the moving and stationary contacts effectively reduce the maximum temperature rise across the three-phase busbar, mitigating localized temperature anomalies and enhancing the temperature rise characteristic of eco-friendly GIS. These findings offer insights for the design and maintenance of eco-friendly GIS, promoting reliable operation and advancing sustainable power systems.