| 摘要 |
PURPOSE:To eliminate fluctuations in voltage and torque by detecting a fluctuation in the secondary resistance from the deviation of the setting and the detecting values of voltage wherein a slip frequency is corrected and controlled in accordance with the value of the secondary resistance. CONSTITUTION:A multiplier 21 operates the product of a magnetic flux command and a revolving speed to output a voltage setting value. A voltage control circuit 24 receives the deviation of the output signals in a voltage detector 23 and the multiplier 21. When the secondary resistance R2 differs from the value set by a slip frequency arithmetic circuit 15, the voltage control circuit 24 outputs a correcting signal of a slip frequency command to correct the value. Namely, when the secondary resistance R2 increased, a correcting signal to increase a slip frequency is outputted from the voltage control circuit 24 and when the secondary resistance R2 decreased, a correcting signal to decrease the slip frequency is outputted from the voltage control circuit 24. |
