| 摘要 |
PROBLEM TO BE SOLVED: To stably and accurately control an AC motor irrespective of the rotational speed. SOLUTION: A U-phase current iu and a W-phase current iw of phase currents iu, iv and iw to be supplied from an inverter 13 to the phases of an AC motor are respectively detected by current detectors 16, 17. A sampling unit 29 current samples the currents iu and iw at each predetermined electric angle based on a pole position θre (electric angle) outputted from a pole position-to-angular speed detector 15. A three-phase AC-to-dq coordinates converter 30 converts the sampling values of the currents iu and iw into the d-axis and q-axis currents id and iq. An averaging processor 31 averages the currents id and iq at each predetermined electric angle period. A vector controller 23 current feedback processes the averaged currents id and iq so as to follow up the currents *id and *iq based on a torque command *T. |
