| 摘要 |
PURPOSE:To improve the stability at regenerative rotation time, to increase the stabilizing range and to improve the dynamic characteristic by differentiating the value divided by a frequency command value at the multiplied value of the voltage of an intermediate circuit by an input current. CONSTITUTION:An inverter is controlled by a multiplier 22 for multiplying the voltage VDC of a DC intermediate circuit of a current type inverter by an input current, a divider 23 for dividing the output of the multiplier 22 by the frequency command value from a voltage instruction unit 21, by differentiating the output of the divider 23 by a differentiator 24, subtracting by a subtractor 30 the differentiated value by the frequency command value through an oscillator 18 and a frequency divider 17. Thus, the stability is improved for any of the motor driven and regenerative states. Since the current is not directly differentiated by the conventional current differentiating stabilization system, the differentiating gain of the differentiator can be readily set. |
