AC rotating machine control device and electric power steering device equipped with same

An AC rotating machine control device comprising:

• an AC rotating machine;
• a rotational position sensor for detecting a rotational position of the AC rotating machine;
• sensor abnormality determination device for determining that the rotational position sensor is abnormal, when abnormality of the rotational position sensor has been continuously detected for a predetermined determination period;
• rotational position estimator for calculating an estimated rotational position of the AC rotating machine when the rotational position sensor is determined to be abnormal;
• power limiting control for limiting drive power supplied for driving the AC rotating machine;
• and
• power feed for, when the sensor abnormality determination device determines that the rotational position sensor is abnormal, on the basis of the estimated rotational position, supplying the AC rotating machine with power obtained by adding rotational position estimation power supplied for the rotational position estimator to estimate the rotational position, to the drive power limited by the power limiting control, wherein
• after the sensor abnormality determination device detects the abnormality, the power limiting control starts to limit the drive power by a time when the sensor abnormality determination device determines that the abnormality occurs, and limits the drive power by a predetermined value at least during a predetermined period that allows estimated error of the estimated rotational position to fall within a predetermined range, and thereafter, limits the drive power so as to be increased from the predetermined value for limiting the drive power.

An AC rotating machine control device comprising:

• an AC rotating machine;
• a rotational position sensor for detecting a rotational position of the AC rotating machine;
• sensor abnormality determination device for performing determination as to abnormality of the rotational position sensor;
• rotational position estimator for calculating an estimated rotational position of the AC rotating machine when the rotational position sensor is determined to be abnormal;
• power limiting control for limiting drive power supplied for driving the AC rotating machine;
• induced voltage acquiring device for acquiring induced voltage of the AC rotating machine;
• and
• power feed for, when the sensor abnormality determination device determines that the rotational position sensor is abnormal, on the basis of the estimated rotational position, supplying the AC rotating machine with the drive power limited by the power limiting control, wherein
• the power limiting control limits the drive power, below a drive power that would be supplied to the AC rotating machine if no abnormality of the rotational sensor is determined, since the sensor abnormality determination device determines that the abnormality occurs at least until the induced voltage of the AC rotating machine becomes equal to or smaller than a predetermined value.

An AC rotating machine control device comprising:

• an AC rotating machine;
• a rotational position sensor for detecting a rotational position of the AC rotating machine;
• sensor abnormality determination device for determining that the rotational position sensor is abnormal, when abnormality of the rotational position sensor has been continuously detected for a predetermined determination period;
• rotational position estimator for calculating an estimated rotational position of the AC rotating machine when the rotational position sensor is determined to be abnormal;
• power limiting control for limiting drive power supplied for driving the AC rotating machine;
• induced voltage acquiring device for acquiring induced voltage of the AC rotating machine;
• and
• power feed for, when the sensor abnormality determination device determines that the rotational position sensor is abnormal, on the basis of the estimated rotational position, supplying the AC rotating machine with the drive power limited by the power limiting control, wherein
• after the sensor abnormality determination device detects the abnormality, the power limiting control starts to limit the drive power, below a drive power that would be supplied to the AC rotating machine if no abnormality of the rotational sensor is determined, by a time when the sensor abnormality determination device determines that the abnormality occurs, and limits the drive power at least until the induced voltage of the AC rotating machine becomes equal to or smaller than a predetermined value.