Application of specialized software for calculation of magnetic field in the turns of switched reluctance motors stator windings

Abstract

Background: The article describes the process of occurrence of additional losses in the extreme turns of the copper stator windings, based on physical laws. The causes of the skin effect in the stator windings of a switched reluctance motor (SRM) are presented, an assessment of the skin effect influence degree on additional losses in the SRM of medium and high power. 2D-model of the SRM sector in COMSOL Multiphysics software package is created to specify distribution of magnetic field in the SRM stator windings and to quantify the amount of additional losses. А comparison of the magnetic field distribution of the SRM configuration 12/8 obtained in the FEMM program and the SRM magnetic field distribution built in COMSOL Multiphysics software package is presented to assess the reliability of the results. Aim: Calculation of the magnetic field distribution in the turns of the stator winding by building a phased 2D-model of the SRM sector (pole division) in COMSOL Multiphysics software package to quantify the amount of additional losses caused by eddy currents in the windings. Methods: COMSOL Multiphysics software package is used to build 2D-sector of the SRM. To obtain results on the distribution of electromagnetic fields within the simulated area, finite element methods (FEM) are used to estimate income adjustments, the results are compared with calculations in the FEMM program. Results: The patterns of the magnetic field distribution of the SRM obtained in COMSOL Multiphysics software package and in FEMM program confirm the presence of a skin-effect in the extreme turns of the stator winding. It can reduce the energy efficiency of the SRM and cause local overheating of the winding turns. As a result of the simulation, the picture of the magnetic field distribution of the SRM obtained in the FEMM program is similar to the picture of the magnetic field distribution of the SRM obtained in COMSOL Multiphysics software package. Ratio error of the values of the magnetic induction of different parts of the SRM is 37 %. It is acceptable and it indicates the correctness of computer modeling in COMSOL Multiphysics software package. Conclusion: The patterns of the magnetic field distribution SRM in COMSOL Multiphysics software package and in the FEMM program confirm the presence of the skin-effect in the extreme turns of the stator winding, which will allow further research in the field of determining the numerical values of additional losses using 2D-model, and proceed from 2D-model to 3D-model of the SRM.