Air-Gap Magnetic Field Distribution in Outer Rotor PM Brushless DC Motors

This paper presents geometric modeling techniques by (Finite Element Method Magnetics) FEMM which have been used for determination of the magnetic field inside the air gap of a Permanent-Magnet (PM) Outer Rotor Brushless DC (ORBLDC) Motors. These models offer the benefit of a fast computation and therefore they can be used as a common model in an optimization technique. Deliberate the magnetic fields inside the air gap numerically for the given slotted structure. This work can be applied in the design of PM motors where is a requirement to minimize noise and torque ripple, maximize efficiency and a continuing need for improvements in the accuracy and firmness of design calculations.