| 摘要 |
PURPOSE:To suppress torque fluctuation, by detecting the torque fluctuation through a current effective-value during acceleration or deceleration, and by setting a correction value for suppressing the fluctuation. CONSTITUTION:By current detecting sensors 10a, 10b, the momentary value of two-phase phase-current among three-phase current for output directed to an induction motor 4 from an inverter 3 is detected, and the output is directed to a current effective-value detector 11. An effective value I through the detector 11 is squared, and the output is directed to the slip frequency correcting circuit 12 of a following step. The correcting circuit 12 is composed of a differentiator 12a and a slip frequency correction setting unit 12b, and by a slip correction value omegasn, slip frequency omegas determining the speed characteristic of the induction motor 4 to which output is directed from a slip setting unit 5b is corrected. As a result, torque pulsation based on the fluctuation of torque generated during acceleration or deceleration can be suppressed. |
