40.5 kV环保型开关设备大电流温升特性研究OA

Environmentally friendly switchgear using clean air as the insulation medium meets the requirements of green environmental protection concepts and the"dual carbon"target.Dead tank type high-pressure products are more likely to solve both insulation and heat dissipation problems and,however,their high current heating and tem-perature rise problems are still prominent.In response to the temperature rise problem encountered in the develop-ment of 40.5 kV/2500 A high current environmentally friendly switchgear at 1.1 times of the rated current,a three position switch and busbar prototype model are constructed in this paper,the electromagnetic-thermal-flow multi physics coupling simulation method is adopted to study its temperature rise characteristics and the simulation result is verified through testing.The structural optimization of the original prototype model is performed and the tempera-ture rise before and after the structural optimization is simulated and compared.Under natural cooling conditions at 2 750 A,the maximum temperature rise of the original structure is 66.2 K,and that of the new structure is 52.6 K.After optimization,the temperature rise is decreased by 13.6 K,significantly improving the overall design margin of the product.The whole switchgear prototype,including the three position switch,busbar module,and circuit break-er module,successfully passed the temperature rise test at 2750 A under natural cooling conditions.