Performance analysis of Buck-Boost and Cuk converter-fed brushless DC motor drives

This paper presents a detailed analysis on the performances of Buck-boost and Cuk power factor converter-fed sensor-less Brushless DC (BLDC) motor drives. BLDC motors are widely preferred for low-power applications due to their high efficiency, faster dynamic response, high ruggedness, high power density, long operating life, noiseless operation, high torque-to-weight ratio and higher speed ranges. Speed of the drive is controlled by varying the DC-link voltage of the Voltage Source Inverter (VSI) feeding the motor. Switching losses in the Voltage Source Inverter are reduced by electronic commutation of the BLDC motor, thereby switching the solid state switches of the VSI at line frequency. The converters are operated in Discontinuous Conduction Mode (DCM) to achieve inherent power factor correction (PFC) at AC mains. Voltage mode control is used adjust the duty ratio of the PFC converter switch. Direct Back-EMF Zero Crossing Detection method is used for the sensor-less control of the BLDC motor. The performance of the drive is evaluated using the selected converters over a wide range of speeds. A unity power factor is achieved with power quality indices acceptable within the recommended limits of IEEE 519 standard.. (C) 2019 Elsevier Ltd. All rights reserved.