| 摘要 |
PROBLEM TO BE SOLVED: To provide a three-phase rectifier current limiting apparatus at a low cost which is compact without installing a circuit breaker on the primary side of a transformer of a three-phase AC system. SOLUTION: The respective primary sides of transformers T1 to T3 are connected in series with the three-phase AC system 14, one of the secondary sides of the transformers T1-T3 is shorted, and a pair of rectifier elements connected in parallel where a positive and a negative poles are inverted are connected with the other side, corresponding to each phase. Thus a three-phase rectifier circuit 11 is constituted. The opposite sides of the rectifier elements connected with the transformer are divided into positive and negative and connected. A DC reactor L is connected between the positive and the negative, thus constituting the three-phase rectifier current limiting apparatus. Out of three pairs of rectifier elements constituting three phases, two pairs of rectifier elements constituting two phases are thyristors TH1 to TH4, and a pair of rectifier elements constituting one residual phase are diodes D5, D6. When an overcurrent is detected because of system failure, the thyristors TH1 to TH4 are turned off.
|
