SYNCHRONOUS MACHINE STARTUP DEVICE

摘要

In a synchronous machine starting device, an AC voltage detection unit (8) detects AC voltage supplied to an armature of a synchronous machine (4) through an electric power line (LN) from a power conversion unit (71). The AC voltage detection unit (8) has a first output end and a second output end isolated from the electric power line (LN), transforms AC voltage supplied through the electric power line (LN) at a first ratio to output the transformed voltage from the first output end, and transforms AC voltage supplied through the electric power line (LN) at a second ratio and then limits the transformed voltage to a prescribed positive voltage value or lower and a prescribed negative voltage value or higher for output from the second output end. Then, a detected voltage selection unit (51) selects one of the voltage received from the first output end and the voltage received from the second output end, and outputs the selected one to a rotor position detection unit (11). The rotor position detection unit (11) detects a rotor position of the synchronous machine (4) based on the voltage received from the detected voltage selection unit (51). A power conversion control unit (19) controls the power conversion unit (71) based on the detected rotor position.