| 摘要 |
PURPOSE:To enable to accurately control the high speed response and the speed of an induction motor without using a speed detector by controlling the components of the phase currents of the motor of 90 deg.C phase difference with respect to the phase references of a transformer output to be proportional to the exciting current command. CONSTITUTION:2-axial components ed, eq of a motor voltage are detected by voltage component detectors 7, 8. An excitation phi can be detected as an induced electromotive force, thereby detecting the signal corresponding to phiq by ed and the signal corresponding to phid by eq. The signal ed is applied to an adder 9 together with the output signal of a rate-of-change limiter 4, and f1 is controlled to always become ed=0(phiq=0). The detection signal eq is converted at an addition point 21 to a speed signal (omega), the deviation between the speed command signal and the signal (omega) from the limiter 4 is amplified in the amplifier 5, thereby controlling the rotating speed in response to the command. |
