| 摘要 |
PURPOSE:To reduce the capacity of a capacitor for smoothing, and to enable sharp deceleration by giving frequency command signals so as not to cause the rise of DC voltage due to regenerative power even when the response of a switch for braking delays at deceleration. CONSTITUTION:The frequency command signals a changing in response to the desired operation pattern of an AC motor are generated from the first frequency command signal generation system. The second frequency command signal generation system is composed of a memory circuit 26 memorizing the value of the frequency command signals a by the ON of the first switch and a decreasing rate setting circuit 30 decreasing value memorized to the memory circuit 26 by the ON of the second switch 28 at the predetermined decreasing rate. The signals having larger value in the frequency command signals a, b are outputted from a select circuit 32, the signals c are used as the true frequency command signals, and inverter output frequency corresponding to the signals c is obtained. |
