Sensorless Based Torque Ripple Reduction in Brushless DC Motor

Abstract

Abstract— Brushless Direct Current Motor (BLDCM) has been commonly utilised in fields that necessitate high fidelity and specific control, owing to its simple structure, high power density, high efficiency, high starting torque, long operating life, and prolonged ranges of speed. While considering of the drive part of the motor, the most significant part is commutation control. During commutation, they generate some high torque ripples which is caused by non-ideal commutation currents in the stator windings which confines its application, exclusively at low-voltage fields. Some of the techniques for the mitigation of commutation torque ripples are reviewed here. A complete knowledge of commutation torque ripple was done by proposed phase advancing method for commutation control for diminishing torque pulsations for the complete ranges of speed. An analysis was made in order to design and implement an optimal current vector trajectory for reducing the torque pulsations for the complete speed range. This method utilises terminal voltage sensing technique and the terminal voltages are converted into d-q reference frame and hence those values are compared with specified values in order to generate the commutation signals. Initially the proposed system is simulated with Proportional Integral controller and then with Fuzzy Logic Controller. Simulation of the proposed system was done in MATLAB version 2013a and the results of comparison was made for both PI controller and fuzzy logic controller.