| 摘要 |
PURPOSE:To prevent the flow of unnecessary inrush currents and control currents by selecting the value of the output voltage of a DC-DC converting circuit in value close to the peak value of motor induced voltage and restarting the motor when restarting it after service interruption is returned. CONSTITUTION:When service interruption is returned, the induced voltage of the motor is detected by a detector 5, and the frequency of an inverter in case of restart is set to value equal to the frequency of induced voltage by an arithmetical command circuit 8. The peak value of induced voltage is arithmetically operated from the frequency of induced voltage detected in the output frequency voltage arithmetical command circuit 8, and a voltage command is emitted so that the output DC voltage of a DC-DC converter is equalized to the peak value of induced voltage arithmetically operated. Accordingly, the motor can be restarted and accelerated smoothly without flowing unnecessary inrush currents and control currents when restarting it by restarting a power supply device while using the frequency and voltage as command values. |
