Rotating machine rotational position detecting device and rotating machine rotational position detecting method

摘要

PROBLEM TO BE SOLVED: To provide a rotation position detection device for a rotary machine capable of avoiding wrong correction in the case that a rotation direction of a motor is changed.SOLUTION: A microcomputer, with respect to a detection rotational angle of a motor generator, calculates an average movement amount PHav over a predetermined reference time period, calculates a prediction value Phase_est (Tn) for a rotational angle to be detected this time by using the detection rotational angle at a previous control cycle and the average movement amount PHav, and then, calculates a deviation Phn between the detection rotational angle and the prediction value. An R/D converter outputs an NM (North Marker) signal when the detection rotational angle becomes 0°. The microcomputer performs correction when a rotation number at the time when the NM signal is outputted is a calculation prohibition rotation number or more, and performs no correction when the rotation number is less than the calculation prohibition rotation number. When no NM signal is outputted and when a rotation direction is the same as the previous one, a deviation Phn-1 obtained at a previous control cycle is used for a correction value used for angle calculation for control. When no NM signal is outputted and when the rotation direction is different from the previous one, the correction value is set so as to satisfy Phm=0.