Electric motor control device

An electric motor control device including a controller that controls a multi-phase winding electric motor, the controller including an inverter circuit that supplies power to the electric motor, a current controller that outputs a voltage command value as a drive command of the inverter circuit, a current detector that detects current flowing to each phase of the electric motor, and a failed phase identifier that identifies a location of a failure in the current detector, wherein

• the failed phase identifier has a test voltage command generator, which generates a test voltage command having a frequency higher than a rotational frequency of the electric motor, determines whether or not a magnitude or a phase of a frequency component of the test voltage command included in a detected current value when the inverter circuit is driven with the test voltage command as a drive command is within a predetermined range, and determines that a failure has occurred in a phase that is not within the predetermined range.