CSC BLDC Motor Drive with Power Factor Correction

The application of Brushless DC motors are widely increasing in large number of spheres to extract its advantages in speed control, they are widely replacing induction machines as well as DC machines in industrial applications too. But the main disadvantage of conventional BLDC motor drive using diode bridge at its input side for feeding the VSI inverter are the large amount of harmonics induced in the input supply current which increases the total harmonic distortion as well decreases the power factor. The conventional diode bridge rectifier BLDC drive also has other disadvantages of speed control as it uses high frequency switching of the VSI inverter for speed control which increases the losses and further reduces the efficiency of the drive, further for speed control the number of sensors required are more and hence the cost of the drive increases. To overcome these disadvantages of the conventional diode bridge drives a canonical switching cell converter BLDC drive is used where a CSC converter is inserted between the diode bridge and the VSI inverter which helps in improving the power quality at the input mains as well as controls speed by varying the dc link voltage of CSC.