Harmonics and Torque Ripple Minimization using L-C Filter for Brushless DC Motors

摘要

Abstract—Brushless DC Motors (BLDCM) are widely used in automated industrial applications like Computer Numerical Control (CNC) machinery, aerospace applications and in the field of robotics. The dynamics of this motor should be smooth for many industrial and automated applications and free from unwanted interference. But due high speed switching circuits used in the commutation circuits, the BLDC motor voltage contains harmonics component and this causes high electromagnetic interference problems. During commutation the trapezoidal current pass through each phase causes pulsation in torque during its operation. This work proposes an improved methodology to reduce the high frequency harmonics components and torque ripples using a RC filter connected at the input of the motor. This work is simulated using PSIM and the effect of filter is analyzed with FFT analysis. An experimental setup is developed to analyze the performance of the drive with the proposed system and the experimental outputs were compared with the simulated values and the improvement in performance is analyzed.