Brushless direct current motors (BLDC) are prominent due to their high efficiency and less maintenance. However, BLDC motor applications are limited due to the requirement of a complex controller, the existence of torque ripple, and high cost. This research work describes the comparative analysis of different control strategies of torque ripple reduction in BLDC motors and it discusses various topologies viz. cuk converter, simple voltage modulator scheme, charged capacitor, Z-source inverter, and Quasi- Z source inverter-based toque ripple reduction techniques. The effectiveness of different control strategies has been verified using MATLAB Simulink and it helps to understand different control strategies for torque ripple reduction during the entire speed range. The analysis of MATLAB results reveal that the voltage modulation scheme reduces the torque ripple considerably during the entire speed range along with the noise- less operation of the BLDC motor when compared with other topologies.

Brushless Direct Current (BLDC) motors are advantageous because of their higher efficiency, higher speed operations and higher power density. Industrial applications demand BLDC motors free from torque ripple. The torque ripple is due to the unequal commutation period between the energised phase and unenergized phase current. It is a perilous problem in sensorless BLDC drive as it leads to speed oscillations, acoustic noise, serious faults, and vibration in machines. The torque ripple can be reduced either by improving motor design parameter or by improving the motor control strategy. This paper proposes a Proportional Integral (PI) controller-based control scheme for a cuk converter driven sensorless BLDC motor to reduce the torque ripple. The proposed scheme invokes Zero Crossing Point (ZCP) detection with back emf sensing approach. The presence of inductor reduces the ripple in the input and output currents. The performance of the strategy is verified using MATLAB R2018a Simulink for different operating conditions of a BLDC drive and the results prove that the recommended scheme decreases the torque ripple compared to the conventional scheme.