| 摘要 |
PROBLEM TO BE SOLVED: To provide a converter apparatus protecting a diode bridge from a re-rush current at the time of restoration in the case of an instant power failure. SOLUTION: The converter apparatus is provided with a diode bridge circuit 3 rectifying an AC voltage inputted from the outside through a power switch and outputting a DC voltage to a DC bus; a smoothing capacitor 7 connected between positive and negative DC buses for smoothing an output waveform; and a parallel connection circuit which is inserted between the diode bridge circuit 3 and the smoothing capacitor 7, and constituted of a current limiting resistor 4 limiting a rush current at the time of the initial charging of the smoothing capacitor 7, and a charging relay 5 which is connected in series to the current limiting resistor 4 and opens and closes the current limiting resistor 4. In an instant power failure protection method of the converter apparatus, a controller opens the charging relay 5 and charges the smoothing capacitor 7 through the current limiting resistor 4 when a bus voltage of the DC bus 6 drops to a differential voltage value which is previously set. COPYRIGHT: (C)2007,JPO&INPIT
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