| 摘要 |
PROBLEM TO BE SOLVED: To provide a control device of an AC motor capable of improving accuracy of the torque to be output in a low rotation region in which the rotational speed of the AC motor is low.SOLUTION: A control unit 15 calculates first voltage command values vd_1 and vq_1 on the basis of current command values idand iq, a one-phase current detection value iw_sns to be fed back, and current estimation values id_est and iq_est to be calculated from an electric angle &thetas;e. The control unit 15 also calculates second voltage command values vd_2 and vq_2 on the basis of voltage correction coefficients Kd and Kq which are real machine behavior information on actual behavior of an AC motor 2 corresponding to a phase angle &thetas;i of a current command vector i. When the rotational speed of an AC motor 2 is not more than a determination threshold value A, the control unit switches first control mode based on the first voltage command values vd_1 and vq_1 to second control mode based on the second voltage command values vd_2 and vq_2. This suppresses fluctuation of the torque output from the AC motor 2, thereby improving driveability. |
