Cogging Torque Reduction in PM machines Used in Electro-Mechanical Battery

Electro-Mechanical Batteries have important advantages comparing chemical batteries and using them is popularized specially in Low Earth Orbit satellites recently. External rotor Permanent Magnet machines are used in these systems as Motor/Generator. The main problem of these machines is their cogging torque originated from high strength PM's. Different methods for cogging torque reduction are available, anyway not all of them are applicable in spacecraft EMB’s machines. In this paper different method of cogging torque will be investigated and proper manners will be extracting. Finite Element Method (FEM) simulations are used for this aim.