To control an inverter in the event of an arm failure of a power converter, fluctuation in an output torque is suppressed, and reduction of a total output caused by the failure is suppressed by distributing an output into a plurality of inverters. A power converter for driving a redundant motor having a pair of first and second independent coils, includes: a first inverter circuit connected to the first coil; a second inverter circuit, independent from the first inverter circuit, connected to the second coil; and a first phase relay provided between the first inverter circuit and the first coil. When any one of a plurality of arms of the first inverter circuit fails, the first phase relay shuts off conduction between the failed arm and the first coil, and the redundant motor is driven by operating the second inverter circuit and the remaining arms of the first inverter circuit.