Analysis of Torque Ripple of Permanent Magnet Brushless DC Motor

 DOWNLOAD

With the development of permanent magnetic material and pow ercomponents, the performance of permanent mag net brushless DC motors has been greatly improved in recent years[1] . Perma nent mag net brushless DC motors feature high power to weight ratio, high to rque to inertia ratio and excellent dynamic performance, etc, and overcame the problem of regular maintence required for brushes while maintaining good control characteristicssimilar to those of co nventio nal DC motors,and so found wide applicatio ns in robots,spacecraft and NC machines, etc[2 ] . Brushless DC mo to rs of ten operate at low speed, and to rque tripple, as one of the impro tant characteristics for mo to rs, has g reat ef fect on performance of mo to rs because to rque tripple inducessig nificant influences on speed and position accuracy etc, of mo to rsat low speed although torque tripple can be filtered out by the inertia of the mo to r system at high speed[3] .