| 摘要 |
PURPOSE:To reduce a cost by providing initial charging function of an AC intermediate capacitor in an input side rectifier, and charging through the input side converter of a power converter, thereby omitting an initial charger. CONSTITUTION:A power converter is composed of an input side rectifier 1, two separately-excited converters 2 and a capacitor 4 to transfer energy by differentiating the firing phases of the converters 2. A smoothing reactor 6 is provided at the input. In order to charge the capacitor 4 necessary for initial charging, the thyristors 23, 24 of the converters 2 are fired to gradually vary the rectifier 1 from a pulse shifting state to become a firing angle alpha>150 deg. to the direction of alpha=90 deg., thereby initially charging capacitors 41, 43 in a peak charging system in the polarity as shown. After the charging, the thyristors 23, 24 are extinguished, and the start is completed by the similar sequence to the conventional manner. |
