Research on PFC (Power Factor Corrected) converters for attaining an improved power quality at the AC mains became popular after the stringent limits were imposed by international power quality standards such as IEEE – 519 and IEC-61000-3-2. Power quality indices such as PF (Power Factor), DPF (Displacement Power Factor), THD (Total Harmonic Distortion) and CF (Crest Factor) of the supply current are limited to within certain prescribed value by these standards for different classes of equipment. The aim of development of this work is to design a brushless DC motor (BLDC) drive fed by Boost Integrated Flyback Rectifier Converter to improve the power factor and for a wide range of speed control using dc link voltage control. The BLDC motor operates in sensorless feedback control i.e., back emf zero crossing detection is implemented in this work in order to reduce the usage of hall position sensors. A reduced sensor topology is derived by utilizing a BIFR converter to operate in a dual DCM (Discontinuous Conduction Mode) thus utilizing a voltage follower approach for the PFC (Power Factor Correction) and voltage control. A new approach for speed control is proposed using a single voltage sensor. The speed of the BLDC motor drive is controlled by varying the DC link voltage of the front end converter. The integrated boost converter operating in DCM acts as an inherent power factor pre-regulator. The design is implemented using MATLAB/SIMULINK.
