| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the dimensional reduction of a three-phase AC-DC converter. SOLUTION: Series circuits comprising first, second, and third bidirectional switches Qa , Qb , and Qc and first, second, and third primary windings N1a , N1b , and N1c of a transformer 2 are connected between respective lines of three-phase AC input terminals 1r, 1s, and 1t. A full-wave rectifier circuit is connected with the secondary windings N2 of the transformer 2. The first, second, and third bidirectional switches Qa , Qb , and Qc are controlled to be turned on/off successively. A period while all the bidirectional switches Qa , Qb , and Qc are simultaneously turned off is provided. The secondary windings N2 are short- circuited in the period while the first, second, and third bidirectional switches are simultaneously turned off to suppress an overvoltage.
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