| 摘要 |
PROBLEM TO BE SOLVED: To enable restraining a circulating current, when the number of parallel connections of converters is large by obtaining a mean current of each phase of each converter from a detected combined current, and correcting an output command value from the outside according to the deviation between the mean current and the output current of each phase. SOLUTION: U-phase output currents I1u, I2u, I3u of converters 7-1, 7-2, 7-3 are combined via reactors 9-1u, 9-2u, 9-3u, and supplies a converter combined current Iu to the U-phase of a secondary winding of a generator-motor 13. A circulating current is obtained from the deviation between a mean output current of combined current detected values IFAu, IFAv, lFAw and converter output current detected values IF1u, lF1v, IF1w of the converter 7-1. By multiplying the circulating current with a gain, converter output voltage command values Vu*, Vv*, Vw* are corrected so as to reduce the circulating current. As a result, the circulating current flowing through the converters 7-1, 7-2, 7-3 can be restrained. |
