| 摘要 |
PURPOSE:To reduce the size and the capacity of an initial charger by firing to shortcircuit upper and lower arms of the prescribed phase of the input side converter of a power converter to substitute for a flywheel operation together with a rectifying converter. CONSTITUTION:A power converter is composed of an input side rectifier 1, two converters 2 and a capacitor 4 to convert energy by controlling the firing phases of the converters 2. A smoothing reactor 6 is provided at the input. In this case, the thyristors 22, 25 of the converters 2 are operated at flywheel time to omit a conventional flywheel thyristor. The capacitor 4 is initially charged by an initial charger 9 in the polarity as shown. Thus, when the charging voltage arrives at the final value, a thyristor 21 is fired to commutate the thyristor 22 to the 21 by the initial voltage of a capacitor 41, thereby completing a flywheel operation. Then, the converters 2 are normally fired and started. |
