| 摘要 |
PROBLEM TO BE SOLVED: To make pseudo sine waves with little distortion by simple method when driving stator winding by sine waves, so as to solve such a problem that using trapezoid waves for the drive of stator winding of a brushless motor or the like can reduce noise or vibration, however the torque ripple is large. SOLUTION: A sine wave where broken lines are approximated is made by making a compensating waveform from a three-phase trapezoid waveform having a plane at 60 deg. in electric angle, a waveform two-thirds the amplitude of the above three-phase trapezoid wave and fixed in amplitude, and a waveform one-third the amplitude of the above three-phase trapezoid wave and fixed in amplitude, and compensating the instantaneous amplitude of each phase so that the value where the above compensating waveform is added to the amplitude of the above three-phase trapezoid waveform may be the amplitude of the new three-phase waveform. |
