| 摘要 |
PURPOSE:To suppress the torque vibration by slip frequency and torque ripple by getting the modified voltage command value being obtained by subtracting torque computing element output from voltage command value output. CONSTITUTION:This device is provided, on output side of a voltage type inverter 1, with a current detector 15, and is provided with a torque computing element 16, which receives the output of a current detector 15 and the output of a magnetic flux computing element 4, and is additionally provided with a computing element 7 which outputs a voltage command value Vr', receiving the output of an adder 13 and the output of the computing element 16. And, if toad torque increases, the torque tau of the output of the torque computing element 16 increases, and the voltage command value proportionate to the inverter frequency becomes small by the subtracter 17, and if the inverter frequency is developed, the slip frequency of a motor decreases, so load torque decreases, and the increase of load torque by torque ripple is suppressed. Conversely, even if load torque decreases by torque ripple, the decrease of load torque is suppressed. As a result, the load torque becomes stable, and the abnormal vibration of the motor can be suppressed. |
