Finite element modelling of electromagnetic force densities in DC machines

The authors describe theory and modeling tools that have been developed to provide the designer with qualitative and quantitative data on a proposed structure. In particular, a complete study has been performed on DC machines and the repartition of electromagnetic force densities on the rotor and stator. The exact expression of the electromagnetic forces and the assumptions that allow a correct computation are discussed. The modulation effect and corresponding excitation due to slots and teeth are illustrated as well as the deformation of pole tips. The example provides a good idea of the capabilities of the software