Abstarct: The structural saliencies and the voltage source inverter feeding stator windings are two main factors for producing the torque pulsations. The cogging torque ripple is produced by interaction between the rotor magnetic field and the stator slots. This can be reduced substantially with optimal design of the stator slots and teeth and using an appropriate shape for the rotor salient poles. baxsed on many investigations carried out in the field of optimization methods, no further improvement of the performance is expected by modifications of structural configures unless a substantial revolution arises in the technology of the conductors or magnetic materials. Due to this, recent researches are concentrated on the improvement of the produced voltage quality and modulation techniques of the inverter in order to limit the torque pulsation and speed ripple. In this thesis, efforts are focused on improving the motor performance characteristics, especially reduction of torque pulsations using proper feeding methods. Stator windings of a sinusoidal-type of BLDC motor are fed by different modulation techniques and performance characteristics of the motor drives are compared to each other. The results are illustrated using the hysteresis modulation inverter. The performance characteristics of the motor are improved with proper hysteresis band width. In the thesis, the performance characteristics of a drive fed by two different multilevel inverters were shown. Meanwhile, the equivalent resistance of core loss is considered as well as switches of the power inverters are selected baxsed on the motor power and flowed current through switches, in both cases. A portion of the thesis because of application of the multiphase motors in the military industries and much growth in the field of fuzzy logic was also assigned to the speed control of an eleven-phase PMBLDCM using a fuzzy incremental controller and was simulated a nine-phase PMBLDC motor with an actual inductance matrix.