| 摘要 |
PROBLEM TO BE SOLVED: To perform operation continuously by making both three-phase and single-phase AC power supplies available and switching to single-phase operation without passing an overcurrent even when phase interruption occurs during three-phase operation. SOLUTION: An N phase rectifier circuit having two capacitors connected in series between the DC output terminals of a bidiredctional switch circuit and controlling the voltage of the capacitors individually by connecting the series joint to the bidirectional switch circuit comprises a single-phase AC power supply 1b and a voltage detector 3<SB>ST</SB>connected between AC input terminals S and T, voltage detectors 6<SB>C1</SB>and 6<SB>C2</SB>of the capacitors, voltage adjusters 34a, 34b and multipliers 35<SB>T</SB>, 35<SB>Ta</SB>generating an input current command value for making the voltage between terminals follow up the DC voltage command value of each capacitor using the input voltage, current detectors 4<SB>S</SB>and 4<SB>T</SB>for detecting AC input current, and current adjusters 36<SB>S</SB>-36<SB>Ta</SB>and comparators 37<SB>S</SB>-37<SB>Ta</SB>generating the drive signal of a switching element such that the AC input current follows up the input current command value. COPYRIGHT: (C)2008,JPO&INPIT
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