A New Pulse Width Modulated PFC Zeta Converter Fed Sensorless BLDC Motor Drive with Position Feedback

Sreedevi K J, C Sojy Rajan

Abstract: A New Pulse Width Modulated Zeta DC-DC Converter employed as Power Factor Correction converter feeding a BLDC (Brush Less DC) motor drive is proposed. Zeta DC-DC converter which lies between an uncontrolled bridge rectifier and a dc link capacitor is used to control the voltage of the dc link capacitor. The Brush Less DC motor is fed from a single phase supply. The DC link capacitor is in between the Zeta Converter and a VSI (Voltage Source Inverter). A voltage follower approach is used to control the dc link voltage of the Zeta converter and the converter is working in DCM (Discontinuous Conduction Mode). To eliminate the requirement of hall effect position sensors a sensorless control of BLDC motor is used. For this sensorless operation, inverter pulses are generated by back emf estimation of the motor drive. A MATLAB/Simulink environment is used to simulate the model. A wide range of speed control is possible with high PF (Power Factor) and improved PQ (Power Quality) at the ac mains supply.

Keywords: DCM, PFC, BLDC motor, Zeta, VSI