Single-phase and three-phase compatible ac-dc conversion circuit and method of detecting input current thereof

Abstract

An AC-DC conversion circuit provides a three-phase power source. The AC-DC conversion circuit includes a first inductor, a second inductor, a third inductor, a switch bridge arm assembly, and a control unit. The switch bridge arm assembly includes three switch bridge arms, and each switch bridge arm includes an upper switch and a lower switch. A plurality of common-connected nodes between the upper switches and the lower switches are coupled to the three-phase power source through the first inductor, the second inductor, and the third inductor. The control unit turns on the upper switch and the lower switch to provide a current detection loop. The control unit acquires a magnitude of a first current flowing through the first inductor and a magnitude of a third current flowing through the third inductor, and determines whether a current detection mechanism of the first current and the third current is normal.