The influence of finite element discretisation on the prediction of cogging torque in permanent magnet excited motors

The accuracy of the predicted torque from a finite-element calculation is determined largely by the level of discretization, as well as the evaluation method employed. The stored energy is used to gauge the adequacy of the meshing density in a finite element model for the prediction of the cogging torque in permanent magnet excited motors. The relationship between the stored energy and the torque predicted by both the energy method and Maxwell stress integration is discussed and demonstrated by case studies, and recommendations for their implementation are presented