This paper aims to present an innovative three-dimensional (3D) homogenization method for rectangular wire winding, aiming to enable fast and accurate thermal analysis, which is essential for the design and safety assessment of electrical coils.
The homogenization process begins by defining a periodic microscopic unit cell that represents the internal structure of the winding. The equivalent thermal resistance of the unit cell is calculated along three orthogonal axes, from which the effective thermal conductivity in each direction is derived. The effective thermal properties of the equivalent homogeneous and anisotropic material are determined to model the thermal behavior of the original cell. These properties are then used to model the thermal behavior of the entire winding. To validate the method, a thermal equivalent circuit (TEC) is developed and used to analyze the coil’s thermal performance.
The results of the thermal analysis based on the homogenized model closely match those from detailed simulations, confirming the reliability of the proposed approach. The TEC effectively captures the temperature distribution and accurately identifies the hotspot location in the winding. The study includes both copper and aluminum conductors, revealing that the conductor material does not alter the hotspot’s location.
The model assumes constant input power by reducing the coil current in response to increased resistance due to temperature rise. This simplifies the analysis but may not account for all real-world operating conditions.
This study introduces a novel 3D homogenization technique for rectangular wire winding, coupled with a TEC model. The proposed method enables efficient and precise thermal analysis, offering significant benefits in identifying critical thermal points, particularly the hotspot, in coil designs.
