| CPC H02P 25/026 (2013.01) [H02P 6/18 (2013.01); H02P 2203/03 (2013.01); H02P 2207/05 (2013.01)] | 5 Claims |
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1. A magnetic pole position detection device configured to detect a magnetic pole position of a rotor of a synchronous motor, the device comprising:
an excitation commanding section configured to excite the synchronous motor while changing a current phase of an excitation current for exciting the synchronous motor from an initial value that is preset; and
a torque-zero determination section configured to determine whether torque generated on the rotor has become zero while the excitation current is flowing through the synchronous motor,
wherein the excitation commanding section, after having excited the synchronous motor with the initial value of the current phase, continuously performs an operation of exciting the synchronous motor in such a manner that a value obtained by subtraction processing for subtracting, from the initial value, a phase angle corresponding to a cumulative value of a movement amount of the rotor from a start time point of exciting the synchronous motor with the initial value of the current phase, is taken as the current phase of the excitation current until the torque-zero determination section determines that the torque has become zero, and
the excitation commanding section acquires the value obtained by the subtraction processing as a magnetic pole initial position at a time of the determination made by the torque-zero determination section that the torque has become zero.
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