| 摘要 |
PURPOSE:To obtain a power converting system which can withstand against monentary power interruption for a long time and in which restart after momentary power interruption and turn ON of power can be carried out stably regardless of the conditions on the power supply side for a voltage type inverter or the number of inverters on the load side. CONSTITUTION:Converter side and inverter side are controlled independently based on the terminal voltage of a smoothing capacitor 4 interposed between a converter 3 and an inverter 6 and when the terminal voltage of the smoothing capacitor 4 drops below a lower limit during operation of the converter 3, a converter switch element is gated OFF thus operating the converter in diode rectification mode. Consequently, power to be regenerated from the smoothing capacitor 4 to the power supply side is suppressed and sufficient power is stored in the smoothing capacitor 4 in the case of restart. Preferably, lower limit of the terminal voltage of the smoothing capacitor is set lower than that at the time of diode rectification. |
