考虑弯曲效应及层叠结构的高频变压器铁芯温度分析

Temperature analysis of high frequency transformer iron core considering bending effect and cascade structure

作为电力电子变压器(PET)的核心元件,高频变压器(HFT)的紧凑化和轻量化设计使其具有较高的功率密度的同时,也引起了极为突出的损耗和温升问题,因此热分析对HFT的可靠、安全运行尤为重要。为了精确模拟和计算非正弦激励条件下HFT的温升特性,本文构建了计及纳米晶弯曲效应的铁芯分区几何模型,并在磁热耦合分析中考虑了温度对散热条件的动态影响。在此基础上,本文在假设纳米晶各向同性电导率的前提下,提出一种磁场与热场之间数值降维耦合的求解方法,进一步节约了计算成本。最后,搭建HFT温升测试平台,对HFT铁芯温升进行实验研究,通过将仿真结果与实验数据对比,验证了本文所建立模型的准确性和有效性。

As the core components of power electronic transformers,high frequency transformers(HFT)have high power density due to their compact and lightweight design,but it also causes very prominent problems of loss and temperature rise.Therefore,thermal analysis is particularly important for the reliable and safe operation of HFT.In order to accurately simulate and calculate the temperature rise characteristics of HFT under non⁃sinusoidal excitation conditions,a geometric model of iron core partition is constructed taking into account the bending effect of nanocrystalline,and the dynamic influence of temperature on heat dissipation conditions in the magneto⁃thermal coupling analysis is considered.On this basis,under the assumption of nanocrystalline isotropic conductivity,a numerical dimension reduction coupling method between magnetic field and thermal field is proposed,which further saves the computational cost.Finally,the HFT temperature rise test platform is built to conduct experimental research on the HFT core temperature rise.By comparing the simulation results with experimental data,the accuracy and effectiveness of the model established are verified.