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

In this paper, a computer-aided design (CAD) procedure for a radial-flux surface mounted permanent magnet brushless DC (PM BLDC) 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 for which the guidelines and justifications are discussed. The basic sizing equations are derived and used for the design algorithm. Using the developed computer program; three different motors are designed. Finite element (FE) analyses of the designed motors are carried out and the results are discussed.