摘要
温度是反映干式变压器运行状态的重要指标,准确快速仿真温度场分布有利于提升干式变压器的运行可靠性。数值热模型可以准确仿真温度场分布,但存在仿真效率低的问题,难以满足运行需求。因此,根据绕组的周期性分布特征,提出基于等效热参数的干式变压器温度场快速仿真方法。选取绕组周期性代表单元,结合有限元方法和傅里叶定律计算其各向异性等效导热系数(equivalent thermal conductivity,ETC),并根据绕组周期性代表单元的内部结构和材料参数推导等效密度(equivalent density,ED)和等效比热容(equivalent specific heat capacity,ESHC)。基于上述等效热参数建立了干式变压器的简化热模型,采用同一台计算机对简化热模型和精确考虑绕组导线和绝缘结构的完整热模型进行仿真并对比分析。结果表明:简化热模型与完整热模型所仿真的温度场及速度场的分布特征均一致;热点温度的仿真误差保持在±4 K范围之内;在最大网格尺寸相同的条件下,简化热模型的仿真速度是完整热模型仿真速度的193倍。该研究验证了所提出的基于绕组等效热参数的干式变压器热点温度快速仿真方法的有效性。
Temperature is an important parameter reflecting the operation status of dry-type transformer.Accurate and fast simulation of temperature field is important for improving the operational reliability of dry-type transformers.The nu-merical thermal model can accurately simulate the temperature field distribution,whereas the low simulation efficiency of the numerical thermal model is difficult to meet the requirements of operation.Therefore,according to the periodic dis-tribution characteristics of the windings,a fast simulation method for the temperature field of a dry-type transformer based on the equivalent thermal parameters of the windings is proposed to improve the simulation speed of the numerical thermal model.The representative volume element of the periodic structure of the winding is selected,and its anisotropic equivalent thermal conductivity(ETC)is calculated by using the finite element method and Fourier’s law.The equivalent density(ED)and equivalent specific heat capacity(ESHC)are derived from the internal composition and material param-eters of the representative volume element of the windings.A reduced thermal model of a dry-type transformer is developed based on the above equivalent thermal parameters.A full thermal model is developed by accurately considering the winding conductor and insulation structure.The same computer is used to perform simulations for both the reduced thermal model and the full thermal model.The results show that the distribution characteristics of the temperature field simulated by the reduced thermal model and the full thermal model are all consistent,as well as the velocity field;the calculation errors of the hot spot temperatures are kept within the range of±4 K;under the condition of the same maxi-mum mesh size,the simulation speed of the reduced thermal model is 193 times that of the full thermal model.The effectiveness of the proposed fast simulation method for temperature field of dry-type transformers based on winding equivalent thermal parameters is verified.
作者
陈思
盛戈皞
张立静
王丰华
CHEN Si;SHENG Gehao;ZHANG Lijing;WANG Fenghua(Department of Electrical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《高电压技术》
北大核心
2025年第1期97-109,共13页
High Voltage Engineering
关键词
等效密度
等效比热容
等效导热系数
数值热模型
温度场
变压器绕组
equivalent density
equivalent specific heat capacity
equivalent thermal conductivity
numerical thermal model
temperature field
transformer winding
作者简介
陈思,1994-,女,博士生主要从事电力设备多物理场仿真与故障诊断的研究工作,E-mail:miserrabbit@163.com;通信作者:盛戈皞,1974-,男,博士,教授从事电力设备状态评估与故障诊断技术的研究,E-mail:shenghe@sjtu.edu.cn。
