Controller for rotary electric machine and electric power steering apparatus

A controller for rotary electric machine that controls a rotary electric machine which is provided with a stator having plural-phase windings and a rotor having a magnet via an electric power converter, the controller for rotary electric machine comprising at least one processor configured to implement:

• a current detector that detects currents which flows into the plural-phase windings;
• a current coordinate convertor that converts current detection values into a current detection value of d-axis and a current detection value of q-axis on a dq-axis rotating coordinate system consisting of a d-axis defined in a direction of a magnetic pole position of the rotor and a q-axis defined in a direction advanced to the d-axis by 90 degrees in an electrical angle, based on a rotational angle of the rotor;
• a current command value calculator that calculates a current command value of d-axis and a current command value of q-axis;
• a voltage command value calculator that changes a voltage command value of d-axis and a voltage command value of q-axis so that the current detection value of d-axis approaches the current command value of d-axis, and the current detection value of q-axis approaches the current command value of q-axis;
• and converts the voltage command value of d-axis and the voltage command value of q-axis into voltage command values of plural-phase, based on the rotational angle;
• and
• a switching controller that turns on and off a plurality of switching devices provided in the electric power converter, based on the voltage command values of plural-phase,
• wherein, in a case where the current command value of q-axis is a positive value, the current command value calculator changes the current command value of d-axis, based on a deviation between an offset q-axis current command value obtained by subtracting a q-axis offset value which is a positive value, from the current command value of q-axis, and the current detection value of q-axis.