CAD and FE analysis of radial-flux surface mounted permanent magnet brushless dc motor

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, and flux density in the stator back iron, etc. are assumed for which the guidelines and justifications are discussed. The designs arrived at using the developed CAD program are giving required torque within an acceptable tolerance. Also, the efficiencies of the motors designed in each category of fractional, low and medium hp motors using the developed CAD program are sufficiently high in comparison with conventional motors.