| 摘要 |
PURPOSE:To improve the regenerative performance in a high speed range by differentiating the set values of output voltage/output frequency of a variable voltage/variable frequency inverter between under a power drive condition and under a regenerative condition. CONSTITUTION:A reference slip frequency FS0 and a correction slip frequency ES1 in response to a current pattern I based on a response load signal VL, a brake command BF and a power drive and brake command P.B are added to produce a slip frequency FS, and an inverter output frequency F is obtained by the slip frequency FS and a rotating frequency FR. A modulation pulse mode calculator 25 sets a modulation pulse mode N to approximate to a sinusoidal wave. A modulation factor calculator 26 outputs a modulation factor AL so that the ratio F/V of the inverter output voltage V to the output frequency F becomes constant. The F/V under the regenerative condition is set to a value smaller than the F/V under the power drive condition. In this manner, the regenerative performance in a high speed range can be improved. |
