高压同轴GIS母线三维磁-热耦合场的计算与分析

Analysis and Calculation of Magnetic-thermal Coupled Field for High-voltage Coaxial GIS Busbar

以110kV高压同轴GIS为研究对象,通过建立GIS母线的三维电磁场的计算数学模型及磁-热耦合场的有限元仿真模型,同时考虑GIS三相母线,对GIS母线的电磁场及涡流损耗进行了计算.为了分析GIS屏蔽外壳涡流损耗对其温度场影响,结合传热学理论,对比分析了不考虑外壳涡流损耗及考虑外壳涡流损耗两种情况下GIS母线及外壳的温度场分布.仿真结果表明,由于内部空间气体对流作用,GIS内部温度场分布不均匀,导体与屏蔽外壳间的温度呈现上高下低、左右对称的特征,中心导体的顶端是主导体的最高温度点;外壳涡流损耗对温度场分布有一定的影响,温升差在0.5℃左右.本文的研究工作为校核高压GIS的可靠性提供重要的理论参考.

This paper took the actual 110 kV high-voltage coaxial GIS as the research object. Its mathematical model and 3D magnetic-thermal coupled finite element model were both established, and then, the electromagnetic field and eddy current field were analyzed. In order to analyze the influence of the shell ed- dy current loss on GIS thermal distribution, the thermal distributions under the two conditions of taking and not taking the shell eddy current loss were calculated by combining the classical heat transfer theory. The simulation results indicate that the thermal distribution is not uniform because of air convention, and the thermal distribution has the characteristics of bilateral symmetry and from top to below. The highest local temperature rise point is at the top of the GIS busbar. The shell eddy current loss has some effect on the thermal distribution, but the temperature rise difference is in 0.5 ℃. Therefore, the research work can provide important reference for the design and check of high-voltage GIS.