采用氮化铝材料的水冷变压器的热管理方法  

Thermal Management Method for Toroidal Water-Cooling Transformer Using Aluminum Nitride Material

作　　者：王开国 宫金武[1] 石子帅 田杰 潘尚智 查晓明[1] Wang Kaiguo;Gong Jinwu;Shi Zishuai;Tian Jie;Pan Shangzhi;Zha Xiaoming(Hubei Key Laboratory of Power Equipment&System Security for Integrated Energy Wuhan University,Wuhan 430072 China;Wuhan Second Ship Design and Research Institute,Wuhan 430205 China)

机构地区：[1]综合能源电力装备及系统安全湖北省重点实验室(武汉大学),武汉430072 [2]武汉第二船舶设计研究所,武汉430205

出　　处：《电工技术学报》2024年第21期6614-6625,6758,共13页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(52177191)。

摘　　要：干式高频变压器结构紧凑且损耗较高,而低导热系数的灌封材料使得热量易在变压器内部累积,从而导致温升成为限制大功率变压器容量与功率密度提升的重要因素。该文以环形水冷变压器为研究对象,建立了考虑中心圆柱热阻的变压器集总参数热路模型,并通过有限元仿真验证了所建模型的准确性。基于所建热路模型,解释了变压器温度降幅随着水流量的提高趋于稳定的现象。为了进一步增强散热效果,该文提出了一种基于高导热绝缘材料氮化铝的新型散热结构。该结构在热源与水冷板之间建立起低热阻通道,增强了变压器与水冷板之间的传热,变压器的容量和功率密度可进一步提高。最后,通过有限元仿真与25 kHz/160 kV·A高频变压器样机实验验证了所提散热结构的有效性。Dry-type high-frequency transformers typically have compact structures and significant losses.The use of potting materials with low thermal conductivity can lead to heat accumulation within the large-capacity transformer,resulting in temperature rise becoming a limiting factor in increasing the power density of high-frequency transformers.Due to the significant advantages of toroidal cores and water-cooling heat dissipation method,this paper focuses on the thermal management issue of toroidal water-cooling transformers.Because of the axisymmetric structure of the toroidal transformer,the thermal circuit of the transformer can be equivalently described using a two-dimensional model.In order to calculate the temperature rise,this paper establishes a lumped parameter two-dimensional equivalent thermal circuit model of the toroidal transformer based on the thermoelectric analogy theory,with the center and the four surfaces of the magnetic core as temperature nodes.Compared with existing models,the proposed model takes into account the thermal resistance of the central cylinder formed after sealing.The modeling of the thermal resistance between the side and bottom surfaces of the central cylinder is based on the analysis of heat flow path.This heat flow path is a curve,but solving the thermal resistance along the curve is difficult.This paper simplifies it by dividing the heat flow path into horizontal and vertical sections.The thermal resistances of these two sections are in series,so the thermal resistance of the cylinder is the sum of them.The accuracy of the simplification method is verified by finite element simulation.With the established thermal circuit model,the phenomenon that the temperature decrease of the transformer tends to remain constant as the water flow rate increases is explained.The cause of this phenomenon is the relatively high thermal resistance between the heat source and the water-cooling plate,resulting in less heat reaching the water-cooling plate and limited cooling effect.Therefore,it is n

关 键 词：大功率高频变压器 环形水冷变压器 等效热路模型 氮化铝材料 

分 类 号：TM433[电气工程—电器]