| 摘要 |
<p>PURPOSE:To facilitate re-adhesion, by controlling inverter frequency with the output of the weighted average arithmeticunit of the rotational frequency of a plurality of induction motors. CONSTITUTION:By a maximum/minimum value selector 14, the minimum value and the maximum value of the output of pulse generators 7A-7D are selected. By a weigthed average arithmetic-unit 15, the output of the pulse generators 7A-7D is added to, and on power running, from the added value, the maximum value of the output from the maximum/minimum value selector 14 is subtracted, and on regeneration, to the added value, the maximum value is added, and the minimum value of the output from the maximum/minimum value selector 14 is added on the power running, and is subtracted on the regeneration, and the obtained voltage is multiplied by 1/4. By an adder-subtracter 12, voltage for slip frequency f is added to the output of the weighted average arithmetic- unit 15 on the power running, and is subtracted from the output on the regenera tion, and output is directed to an inverter 5.</p> |
