Adjustable Mesh-based Thermal Network Modeling Approach for PMSM Drive System

This paper proposes a novel adjustable mesh-based thermal network modeling (TNM) approach for rapid and accurate thermal prediction of PMSM inverter board. The key is to apply adjustable meshes with scalable features to develop refined regional resolution TNM. First, the cross-shaped mesh unit is proposed with regular sizes and synchro thermal conductance, which can flexibly establish target resolutions. The mesh division is adaptively adjusted to ensure that the mesh boundaries align with key components. Second, the power loss calculations of GaN converter are carried out, while the meshing approach is applied in converters to represent thermal coupling effects with regional junction temperature. Then, the entire TNM is developed with proposed meshes based on thermal circuit theory of algorithm solution and thermal analyses. Because of identical meshing principle, the interface between board and inverters can be easily implemented. Also, variable meshes can more accurately match the boundaries of thermal conductive materials. Finally, thermal evaluation of finite element analyses and experiments are carried out. The effectiveness and rapidity of the proposed adjustable TNM are verified by comparisons in different operations.