Rotary electric machine control device

A rotary electric machine control device that controls a rotary electric machine that includes a rotor in which a permanent magnet is disposed so as to provide magnetic saliency, and that performs feedback control on the rotary electric machine on the basis of a deviation between a current command and a feedback current from the rotary electric machine in a d-q-axis vector coordinate system defined by a d-axis which extends in a direction of a magnetic field produced by the permanent magnet and a q-axis which is orthogonal to the d-axis, the rotary electric machine control device comprising:

• an electronic control unit that is structured to:
• compute a magnetic pole position of the rotor on the basis of an induced voltage generated in the rotary electric machine;
• apply a high-frequency observation signal to the rotary electric machine, and compute the magnetic pole position of the rotor on the basis of a high-frequency component included in the feedback current as a component as a response to the observation signal;
• and
• switch a computation mode for computing the magnetic pole position of the rotor between at least two modes that include a high speed range computation mode in which the magnetic pole position is computed and a low speed range computation mode in which the magnetic pole position is computed, wherein
• the electronic control unit sets a high speed rotation range prescribed by a rotational speed and torque of the rotary electric machine and a low speed rotation range prescribed by the rotational speed and the torque of the rotary electric machine and prescribed on a side on which the rotational speed is lower than that in the high speed rotation range, applies the high speed range computation mode in the high speed rotation range, applies the low speed range computation mode in the low speed rotation range, and sets both a high speed range-side boundary and a low speed range-side boundary so as to be on a side on which the rotational speed is low in the case where the torque is relatively high compared to a case where the torque is relatively low, the high speed range-side boundary being a boundary between a region on a side on which the rotational speed is lower than that in the high speed rotation range and the high speed rotation range, and the low speed range-side boundary being a boundary between a region on a side on which the rotational speed is higher than that in the low speed rotation range and the low speed rotation range.