Title: Reduction of torque ripple due to phase current commutation in BLDC motor using two-level DC bus voltage

Authors: Baby K. Binu; George Saly

Addresses: Department of Electrical Engineering, National Institute of Technology Calicut, Kerala, Pin 673601, India ' Department of Electrical Engineering, National Institute of Technology Calicut, Kerala, Pin 673601, India

Abstract: The main focus of the work is the reduction of torque ripple due to phase current commutation in brushless DC (BLDC) motors. The evolution of torque ripple owing to phase current commutation is discussed and the governing equations are derived. It is observed that, current ripple and hence, torque ripple can be reduced by injecting additional voltage into the dc bus during commutation interval. The magnitude and duration of additional voltage, which has to be injected, are deduced from the expressions of motor phase currents. A new topology is proposed for this purpose in which a boosted voltage is obtained by charging and discharging an inductor during the 'buildup period' and 'freewheeling period' respectively. Simulations had been carried out in PSIM and an experimental set up made to validate the proposed topology. Results show a 60% reduction in torque ripple with an increased steady state speed. The proposed topology uses control strategies using digital gates which make the system control easier, and thus cost effective.

Keywords: brushless DC motors; BLDC; torque ripple; phase current commutation; boosted voltage commutation; DC bus voltage; simulation.

DOI: 10.1504/IJIED.2014.059224

International Journal of Industrial Electronics and Drives, 2014 Vol.1 No.2, pp.105 - 110

Received: 06 Aug 2013
Accepted: 27 Aug 2013
Published online: 24 Jul 2014 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article