BLDC Motor Drive with Power Factor Correction Using PWM Rectifier

Major constraints while using motor drive system are efficiency and cost. Commutation in the conventional DC motors is carried out by commutator which is rotating part placed on the rotor and brushes. Due to these mechanical parts, conventional DC motor consist high amount of losses. Brushless DC (BLDC) Motors are very extensively used motors these days because of its advantages over conventional DC motors. Commutation is carried out with the help of solid-state switches in BLDC motor instead of mechanical commutator as in conventional DC motor. This improves the performance of the motor. BLDC motor draws non-linear currents from the source affecting the loads connected at the source point due to harmonic production. This harmonic production reduces the system efficiency and mainly stresses the loads connected at source point. BLDC drive system with power factor (PF) correction was discussed in this paper. BLDC with normal AC-DC diode bridge rectifier and the performance of BLDC drive with PWM rectifier for power factor correction was discussed. BLDC drive system with PWM rectifier for power factor correction was validated by considering different cases. BLDC motor without power factor correction, BLDC drive with PF correction at starting condition, at steady state and with step-change in DC link voltage models was developed. Torque ripple in BLDC motor drive for these cases were compared. Models were developed and results were obtained using Matlab/Simulink software.