Patent ID: 8604734

Claim:
An electric motor control apparatus comprising: an electric motor; an electric motor driving unit configured to drive the electric motor; and a control unit configured to control the electric motor driving unit, wherein the electric motor driving unit comprises: a current detection unit configured to detect a current flowing through a current detection place provided in the electric motor driving unit, wherein the control unit comprises a current calculation unit configured to calculate a current value of a current flowing through the electric motor from an offset correction value obtained based on a first detection value detected at a time when a current flows through the current detection place and a second detection value detected at a time when a current does not flow through the current detection place, wherein the offset correction value includes: a first offset correction value stored in nonvolatile memory of the control unit at a time of assembling the electric motor control apparatus; and a second offset correction value computed by the control unit while the electric motor is driven, and wherein a time change amount of the second offset correction value is limited so as to become smaller than a predetermined value based on a temperature drift change rate of the current detection unit.