ESIC Seminar Ebrahimi Sept 3

Overview of Brushless DC Motors and Control Methods
for Torque Ripple Reduction
Brushless DC (BLDC) motors are widely utilized in many applications due to their low cost, simple manufacturing, and good torque-speed characteristics. The BLDC motors typically use the basic six-step commutation, which has a low switching frequency and straightforward switching algorithm. However, the six-step commutation method leads to distorted current waveforms and large torque ripples. This main shortcoming of the BLDC motors can limit their application in servosystems where low torque ripples and low acoustic noise are essential. Several algorithms have been proposed to mitigate the torque ripples in BLDCs. The presenter will first provide an overview of the structure, control, and operation of BLDC motors. Afterward, he will present a novel and straightforward technique to reduce the torque ripples in BLDCs. The analysis will be supported by simulations and experimental results on a typical industrial BLDC motor.