| 摘要 |
PURPOSE:To improve the accuracy of position detection in high speed rotation range by intermittently changing the cycle of stator winding energization, including starting up, according to the speed of rotor rotation. CONSTITUTION:Some of a plurality of stator windings are energized to produce rotating magnetic fields. Further, the combination of stator windings to energize is changed according to the variation in voltage induced in the unenergized windings, and the stator windings are thereby intermittently energized. This cycle of the intermittent energization of the stator windings is changed according to the speed of rotor rotation; the intermittent energization cycle Ta is decreased when the rotor rotation speed is high and increased when low. Thus the speed of rotation of the rotor, including that at the time of starting up, is changed. This improves the accuracy of position detection in high speed rotation range, and makes it possible to expand low speed rotation ranges. |
