| 摘要 |
PURPOSE:To prevent overshoot by reducing an output voltage command value when DC side voltage drops and by increasing the output voltage command value with a specified time delay when it rises. CONSTITUTION:A PWM inverter 3 converts DC power supply 2 into AC power in the voltage and frequency as desires and drives an induction motor 4 on a variable speed. The control is performed with the 2nd phase synthesization circuit 14, the 1st-to-3rd phase pulse distributor 17, etc. On the output side of a voltage detector 21 a voltage variation correction circuit 31 is provided, the output of a sinusoidal wave generator 13A is multiplied by the output of the detector 21 and the product is given as a voltage command value. Similarly, the output of a sinusoidal wave generator 13C is multiplied by the output of the detector 21, and the product is given as another voltage command value. |
