**2. Design of BLDC Motor**

The basic step in the motor design is to fix the rated speed and torque. Based on these particulars, the other parameters of the motor can be selected. Figure 1 shows the structure of a surface-mounted PMBLDC motor.

The stators of BLDC motors are similar to those of three-phase induction motors. The main dimensions depend on the specific electric loading and specific magnetic loading. The procedure for calculating the main dimensions is depicted as a flowchart in Figure 2. The procedure for the selection of stator slots and winding is shown in Figure 3.

In this paper, in order to analyze cogging torque reduction, a 4-pole, 12-slot surfacemounted BLDC motor was used. The design parameters of the motor are shown in Table 1.

**Figure 1.** Topology of surface-mounted BLDC motor.

**Figure 2.** Flowchart for calculation of main stator dimensions.

**Figure 3.** Flowchart for stator slots and windings.

**Table 1.** Design parameters.

