| 摘要 |
PURPOSE: To restrain unnecessary vibration and noise in addition to improved speed controllability at the time of starting. CONSTITUTION: A proportional and integral amplifier 41 for proportioning and integrating a deviation between the speed command SP and detected speed SFB of a motor 3 is provided, the output of the amplifier 41 is added to the speed command, and the result is taken as an output frequency command Fs. An inverter main circuit 2 is controlled as an output voltage command VS which is made to have a fixed ratio to the frequency command by a setter 42 . At the time of starting to operate the motor, a normal/reverse rotation detector 11 detects the rotational direction of the motor, and a static friction torque compensation part 43 bias-adds a torque compensation corresponding to the static friction torque of a mechanical system to the proportional and integral amplifier 4, with a polarity suited to rotational direction at the time of starting to operate the motor. |
