Production friendly design and development of brushless DC machines

Many sophisticated control applications need reliable, maintenance-free and efficient drives. Brushless DC Motor is one of such machine which is now widely used due to compactness of motor and drive unit and replacing large number of conventional machines to a greater extent. The numerous benefits of Brushless DC motors are high torque to weight ratio, higher torque, less inertia and use of electronic commutation. The magnetic fields produced by stator and rotor interact to develop torque. The special construction of stator lamination with concentrated winding are responsible for trapezoidal shape gap flux density distribution and induced EMF. However use of special laminations for stator can be costly with larger material wastage. It is therefore necessary to adopt innovative approach for design of BLDC machine. One of the unusual approach is presented here in which standard laminations used for induction machine are employed in stator of new BLDC machine. Innovative winding arrangement is used to create desired number of poles. The design data is used to simulate analytical model of the machine for validation of design by using finite element analysis. A prototype is also fabricated or judging appropriateness of design.