Electric motor control apparatus

An electric motor control apparatus comprising:nan electric motor;an electric motor driving unit configured to drive the electric motor; anda 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, andwherein 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.

An electric motor control apparatus comprising:nan electric motor;an electric motor driving unit configured to drive the electric motor; anda 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, andwherein offset correction by the second offset correction value is made only when an absolute value of the second offset correction value is of a predetermined value or less.