Comparison of Buck-Boost and Cuk Converters for BLDC Drive Applications with PFC

The devices generally used in industrial, commercial and residential applications need to undergo rectification for their proper functioning and operation. Hence there is a need to reduce the line current harmonics so as to improve the power factor of the system. This has led to designing of Power Factor Correction circuits. This project presents a power factor corrected (PFC) bridgeless (BL) buck?boost converter-fed brushless direct current (BLDC) motor drive as a cost-effective solution for low-power applications. The conventional PFC scheme of the BLDC motor drive utilizes a pulse width-modulated voltage source inverter (PWM-VSI) for speed control with a constant dc link voltage. This offers higher switching losses in VSI as the switching losses increase as a square function of switching frequency. A BL configuration of the buck?boost converter is proposed which offers the elimination of the diode bridge rectifier, thus reducing the conduction losses associated with it. A PFC BL buck?boost converter is designed to operate in discontinuous inductor current mode (DICM) to provide an inherent PFC at ac mains. The simulation results are presented by using Matlab/Simulink software. The proposed concept can be extended with cuk converter for BLDC drive applications using Matlab/Simulink software