PROBLEM TO BE SOLVED: To improve safety of elements of a thyristor rectifier at the time of short-circuit failure.SOLUTION: A control unit of a thyristor rectifier includes: a reference phase detection section inputting an AC side voltage of a power converter and outputting a reference phase of the AC side voltage; a gate pulse generation section generating gate pulse input signals on the basis of a predetermined control angle signal and the reference phase output from the reference phase detection section; and a gate pulse changeover section outputting the gate pulse signal selected from the gate pulse input signals on the basis of the gate pulse input signals and a fusing signal of an AC side fuse of the power converter to the power converter.