| 摘要 |
PURPOSE:To suppress vibration and to efficiently drive by providing number-of- exciting phases detector for switching a set value of a set value switching unit in response to the number of exciting phases so that the total sum of exciting currents of exciting windings becomes substantially equal. CONSTITUTION:In the case of 1 phase-2 phase exciting system, 1 phase exciting state or a 2 phase exciting state is detected by a number-of-exciting-phases detector 6, and a set value in a set value switching unit 5 is reduced at the time of 2-phase exciting state as compared with a 1-phase exciting state. Accordingly, since the set value in the 2-phase exciting state is reduced, an exciting current is controlled to be reduced, and the total sum of the exciting current becomes substantially equal to that at the time of 1-phase exciting state. Therefore, a torque change is reduced, and vibration can be suppressed. In the case of 2 phase-3 phase exciting system, the set value of the 3 phase exciting system is reduced as compared with that in the 2 phase exciting system so that the total sum of the exciting currents of the 3 phase exciting state can become substantially equal to the total sum of the exciting currents in the 2 phase exciting state. |
