Patent ID: 8823300

Claim:
An electric motor control device comprising: a control section adapted to control supply of a drive current to an electric motor; and a rotational speed detection section adapted to detect a rotational speed of the electric motor, wherein the drive current includes a d-axis current and a q-axis current, and the control section calculates a q-axis current command value based on a torque command value to the electric motor, calculates a d-axis current command value using a difference between the rotational speed of the electric motor and a previously determined base rotational speed of the electric motor, and the q-axis current command value, performs vector control on the electric motor using the d-axis current command value and the q-axis current command value, assuming that a gain coefficient is Kd, the q-axis current command value calculated based on the torque command value is Iqr, the rotational speed of the electric motor is ω, and the base rotational speed of the electric motor is ωbs, and the d-axis current command value Idr is expressed as follows Idr=Kd×Iqr ×(ω−ω obs ).