Comparisons in the Analytical, 2D and 3D Analyses of a Low-cost 2-Pole Permanent Magnet Commutator Motor

The paper puts forward a full 3D finite element analysis (with transient solutions), a 2D finite element analysis (with magneto-static solutions) and an analytical analysis of a small 2-pole commutator motor with three armature slots and coils. These machines are very common low-cost machines but the amount of recent literature on their design (using modern CAD packages) is quite small. The results illustrate the cogging nature of the torque and also the drawbacks in the 2D finite element analysis. Various design changes are investigated using the different analysis techniques to illustrate that even small motors can be improved by careful addressing of some important design features. These improvements include slot opening variation and the use of different magnet material. A thermal solution is carried out to ensure that it does not overheat.