At present, different kinds of electric drives, designed for different applications, are widely used in industry. High power density, high torque to inertia ratio, high speed performance capability and good efficiency are some of the distinct advantages of permanent magnet synchronous machine which have made it a reliable choice for high performance applications. Many efforts have been made heretofore to reach smoothness which is a necessary torque characteristic for an advanced drive. Un-ideality of B-EMF waveforms which is the result of un-optimized motor design is considered as an important source of pulsating torque. To compensate unwanted effects of this deficiency, control techniques have been introduced that try to reduce electromagnetic torque ripples caused by B-EMF harmonics by means of motor currents shaping. In this research, optimized reference currents are injected to motor through multiple reference frame (MRF) control method to obtain this goal. Employing MRF method necessitates motor currents components extraction to be regulated to their reference values. Different methods of signal harmonics extraction have been formerly presented, among which adaptive notch filter (ANF) is preferable because of high reliability, good dynamic response and low computational burden for the processor. Therefore, this technique has been utilized in this research to extract three-phase currents harmonics. Control techniques have been simulated in Matlab/Simulink and implemented in experimental setup.
