Torque ripple reduction by using multi-slice Fe modelling of brushless DC motor with skewed magnets

The intention of this paper is to look at multi-slice two-dimensional finite element modeling of a brushless DC motor with and without magnet skew. The results obtained are compared with experimental measurements on a typical machine without skew structure of the magnet. A standard approach to reducing cogging torque is to skew the magnet structure with respect to the rotor. Alternatively, the stator core can be skewed as well. This paper will consider the case of magnet skew only. From the finite element analysis (FEA) results, it shows that the brushless DC motor with 10° magnet skew angle with 5 slices had better performance than the motor with different values of skew angle. Additionally the difference between a physical machine with un-skewed magnets and a model of skewed magnet machine are shown