高导热环氧复合材料干式电抗器热点温升的仿真研究

Simulation study on hot spot temperature rise of dry reactor with high thermal conductive epoxy composite as encapsulating material

干式电抗器的稳定运行影响新型电力系统的输电可靠性。干式空心电抗器包封材料整体由浸有环氧树脂的玻璃纤维丝经高温固化而成。本文采用多物理场耦合有限元方法,考虑干式空心电抗器的包封材料热导率对其热点温升的影响,建立了环氧复合材料的COMSOL微观仿真模型和外电路约束下的干式空心电抗器电-磁、流-热耦合计算模型。将电磁场下的损耗作为热源计算温度场与流场分布,研究在25℃环境温度下常规/高导热环氧复合材料对干式空心电抗器热点温升的影响规律。结果表明:高导热环氧树脂对复合材料热导率的提升效果显著;包封材料本体及周围空气温度场区域中热点温升最大值为103.75℃,出现在内部第4层包封材料的上端处;不同热导率的复合材料对降低干式电抗器的热点温升有明显差异,其中干式电抗器在高导热环氧树脂复合材料下的热点温度降低了7.55℃。

The stable operation of dry-type reactors affects the transmission reliability of new power system.The encapsulating material of dry-type reactor is made of glass fiber filament impregnated epoxy resin cured at high temperature.In this paper,a multiphysics coupled finite element method was used to consider the influence of thermal conductivity of the encapsulating material for dry-type reactor on its hot spot temperature rise,and a COMSOL microscopic simulation model of epoxy composites and an electro-magnetic and flow-thermal coupling calculation model of dry-type reactor under the constraints of external circuits were established.The temperature field and flow field distribution were calculated by using the loss under electromagnetic field as the heat source,and the influence of conventional/high thermal conductive epoxy composites on the hot spot temperature rise of the dry-type reactor at 25℃of ambient temperature was studied.The results show that the high thermal conductive epoxy resin has a significant improving effect on the thermal conductivity of composites.The maximum hot spot temperature rise in the temperature field area of the encapsulating material body and the surrounding air is 103.75℃,which appears at the upper end of the fourth layer of encapsulating material.The epoxy resin composite with different thermal conductivity has obvious difference on decreasing the hot spot temperature of dry-type reactor,and the hot spot temperature of the dry-type reactor with high thermal conductive epoxy resin composite is reduced by 7.55℃.