A Generalized Mesh-Based Thermal Network Model for SPM Machines Combining Coupled Winding Solution

Abstract

In this article, a new equivalent thermal network (ETN) model for surface-mounted permanent magnet machines is proposed by applying a mesh-based method with bidirectional coupled winding solution. The key is to couple the winding temperature distributions with thermal network meshes in stator dynamically. First, the meshing method is proposed and combined in the lumped parameter thermal model to obtain temperature distributions instead of the average temperature. The mesh elements have identical shapes and unified thermal conductivity, which can greatly enhance the modeling flexibility and efficiency. Second, the slot winding is established by a 2-D analytical solution method under segmented boundaries with a temperature gradient. Then, the winding solution is coupled with mesh nodes and integrated in the ETN model to accurately predict the temperature distributions in slot including the maximum temperature and position offset. Finally, the effectiveness of the proposed ETN model is verified by comparison with the finite-element analysis and experimental results.