The subject of zero-ripple torque control in Brushless DC Motors has gained importance due to the growing popularity of small electric motors in consumer electronic applications. A low number of phases and the occurrence of production tolerances give rise to low-frequency torque errors, which manifest themselves as relatively large position errors due to the low inertia of these small drives. With regard to the tight specifications of the controlled performance, reduction of these low frequent torque errors is desirable. In literature, two main approaches have been demonstrated for the analysis and mini mization of torque ripple. One approach is based on Fourier analysis, while the other uses calculus of variations to find optimal current waveforms. In this paper, a new approach is presented for the determination of optimal current wave forms. The approach is based on an analysis of the back-emf’s in the angular domain, and can be used even in the case when both the back-emf’s and the stator resistances show asymmetry. The new approach is compared to the Fourier method in a test case, and shows significant reduction in RMS and average values of the stator currents needed to generate a desired torque.
|Titel||Selected topics in identification modelling and control : progress report on research activities in the Mechanical Engineering Systems and Control Group|
|Redacteuren||P.M.J. Van den Hof, O.H. Bosgra|
|Plaats van productie||Delft|
|Uitgeverij||Technische Universiteit Delft|
|ISBN van geprinte versie||90-407-1077-5|
|Status||Gepubliceerd - 1994|
Huisman, H. (1994). Zero-ripple torque control in brushless DC motors. In P. M. J. Van den Hof, & O. H. Bosgra (editors), Selected topics in identification modelling and control : progress report on research activities in the Mechanical Engineering Systems and Control Group (Vol. 7, blz. 101-107). Technische Universiteit Delft.