FE analysis and CAD of radial-flux surface mounted permanent magnet brushless DC motors

In this paper, a comprehensive computer-aided design (CAD) procedure for a radial-flux surface mounted permanent magnet brushless dc motor is presented. The design variables such as airgap flux density, slot electric loading, winding factor, stacking factor, stator current density, slot space factor, magnet fraction, slot fraction, flux density in the stator back iron, etc., are assumed. The basic output equations are derived and used for the design algorithm. The developed CAD program gives the design data and the calculated performances of the motor. Three different motors of rating 70 W, 2.2, and 20 kW are designed using the developed program and then finite-element analyses are carried out to validate the designs.