THREE-PHASE RECTIFIER DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce a peak current that flows through a three-phase rectifier composed of a bridge rectifying circuit and a smoothing capacitor, and also reduce current harmonics that flow through an AC power supply. SOLUTION: A harmonics reducing device 30 installed between a bridge rectifying circuit 2 and a smoothing capacitor 4 comprises a single-face voltage type conversion circuit 31 composed of a first arm in which a diode 32 and an MOSFET 33 are connected in series, a second arm in which an MOSFET 34 and a diode 35 are connected in series, and a capacitor 36, a small reactor 37, a control unit 38, a voltage detector 39 which detects the voltage at the intermediate connection point between a positive-side output end of the bridge rectifying circuit 2 and the second arm, in other words, between input and output of the harmonics reducing device 30 as VO, and a current detector 40 which detects a current that flows through the small reactor 37 as IL. The control unit 38 controls the current flowing through the small reactor 37. COPYRIGHT: (C)2005,JPO&NCIPI