To improve controllability of an electric motor while preventing a rise in cost required for device configuration.
A controller 10 for the electric motor includes: a magnetic pole position error estimating section 46 for estimating a phase difference Δθe of a γδ coordinate system for a dq coordinate system by utilizing the fact that an induction voltage generated by the motor 11 changes depending on a rotation speed; a rotation speed-magnetic pole position operating section 47 for operating a magnetic pole position estimation value θe from the phase difference Δθe; and a controller 23 for executing current feedback control so that the deviation between a command value of a current to be applied to the motor 11 and a detected value may be zero. The rotation speed-magnetic pole position operating section 47 executes calibration processing for calibrating the result of operation of the magnetic pole position estimation value θe at a predetermined timing in accordance with a position signal to be outputted from a hall IC sensor 33 provided on the motor 11.
COPYRIGHT: (C)2010,JPO&INPIT
Tadashi Takahashi
Yoshifumi Saeki
Suzuki Mitsuyoshi
Kazuya Nishi
Yasuhiko Murayama
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