Multilevel Boundary-Coupled Method for the Efficient Thermal Prediction of High-Frequency Transformers (HFTs) With Cylindrical Windings

作者：Yongliang Dang, Lingyu Zhu, Fengshuo Liu, Fan Zhang, Zhanlei Liu, Shengchang Ji · 发表于：IEEE Transactions on Power Electronics · 年份：2024 · DOI：10.1109/tpel.2024.3521456 · 被引用次数：7 · 研究领域：Induction Heating and Inverter Technology、Thermal Analysis in Power Transmission、Magnetic Properties and Applications

Efficient and accurate thermal prediction is important for the optimal design of high-frequency transformers (HFTs). The configuration of HFTs is typically nonrotationally symmetrical. A 3-D finite-element model (FEM) is utilized for thermal predictions due to its high accuracy. However, its prediction efficiency is unsatisfactory due to three factors. First, the thin wires of HFT windings require a dense mesh in the 3-D FEM, increasing the computation time for each FEM iteration. Second, solving the 3-D physical field requires more computation time than solving 1-D or 2-D fields for each FEM node. Third, temperature-dependent HFT losses increase FEM iterations. The proposed multilevel boundary-coupled method tailors two strategies to enhance thermal prediction efficiency while maintaining satisfactory thermal prediction accuracy: 1)multilevel boundary-coupled strategy: solving the thermal field for the winding with a 2-D rotationally symmetrical FEM, solving the thermal field for the remaining region of the HFT with a 3-D FEM, and coupling the 3-D FEM and the 2-D FEM with their boundary temperatures and 2)temperature-dependent HFT loss estimation strategy: approximating the temperature-dependent HFT losses with the temperature estimated by a lumped parameter thermal model for the FEMs. The first strategy reduces the number of nodes and the dimension of the thermal field in the winding region of the FEM, thereby saving computations for each FEM iteration. The second strategy ...