| 摘要 |
PURPOSE:To reduce the capacity of a power converter and to improve the power factor by connecting a semiconductor switch between DC output terminals connected in cascade with a plurality of semiconductor switching converters, controlling to conduct them and altering the magnitude and the polarity of a load current. CONSTITUTION:Thyristor converters 26a, 26b are connected in cascade at the DC output side, a bride having thyristors 29a-29d is connected to the output terminal of the converter 26a, a bride having thyristors 29a, 29b, 29e, 29f is connected to the output terminal of the converters 26a, 26b, and a compensating field winding 15 for compensating the armature reaction of a synchronous motor 11 for driving a power converter 12 is excited. Accordingly, the thyristors 29a-29f are selected and controlled to be conducted, thereby regulating the current of the field winding 15 and switching the polarity. Then, one converter 26 is bypassed to solely operate the converter, the capacity is reduced, and the power factor and the utility rate are improved. |
