| 摘要 |
PURPOSE:To obtain quick accelerating and decelerating performance while contriving the reduction of magnetic noise, by a method wherein a flux commanding value is changed in accordance with the magnitude of primary current upon stationary running while a rated flux is provided upon accelerating and decelerating. CONSTITUTION:In the condition of stationary running, the output of a coincidence circuit 11 is 'L' level whereby a switching circuit 12 selects the output f(I) of a magnetic flux limit operating circuit 6 and provides the output as the multiplying input of multipliers 9a-9c. Accordingly, a flux commanding value is changed in accordance with the magnitude of a primary current in the condition of stationary running. The output of the coincidence circuit 11 is changed into 'H' level upon accelerating and decelerating. According to this change, a switching circuit 12 selects a value '1' and transmits it to the multipliers 9a-9c. As a result, the flux commanding values OR', OS', OT', inputted from the multipliers 9a-9c into a flux control PWM circuit 3, may be switched to values, providing rated fluxes. |
