Harmonic Control to Reduce Torque Pulsations in Brushless DC Motor Drives.

Abstract

0 6 0 7 2. GOVT ACCESSION NO. 3. RECIPIENT'S CATALOG NUM ER 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED ,.r v~t 20. ABSTRACT (Continue on rsevere side If necessary and identify by block number)-The brushless W machine theoretically offers wide speed range torque characteristics like unto the commutator DC machine. However, in brushless DC motor drive systems there exists a performance deficiency in that at near zero speeds driven mechanical loads can respond. to the pulsating component of developed torque when simple rotor position-activated switching is utilized. This report analytically develops a pulse width modulation control philosophy that reduces torque pulsations to an acceptable level. DD ,R. 1473 EDITION OF I NOV 65 IS OBSOLETE Unclassified SECURITY CLASSIFICATION OF THIS PAGE (Mhen Data gtered) 11 101 lf 111'111j11 1111' *.* ? ZS-L~ 2.2.3 Elimination of Sixth and Twelfth Harmonics of Torque 41 2.2.4 Elimination of Sixth and Twelfth Harmonics of Torque (a-150) 41 2.2.5 Elimination of Sixth and Twelfth Harmonics of Torque (a-400) 50 2.3 450 RPM (1% Speed Case) 59 2.3.1 Unmodulated Phase Voltage 59 2.3.2 Elimination of Sixth Harmonic of Torque 2.3.3 Elimination of Sixth and Twelfth Harmonies of Torque 64 iii Thh: t, TIra J. X'" ... Di i lef, Technical luf ormation Division