| 摘要 |
PROBLEM TO BE SOLVED: To realize vector control with high accuracy of an AC motor at all times by estimating an error on the axial-displacement of a control coordinate axis and an actual magnetic axis. SOLUTION: In the control of the AC motor 12, to which vector control is applied, a d-q rectangular coordinate system which rotates synchronously with a rotor or a magnetic-flux vector is used as control coordinates, the square of the amplitude of a detecting-current vector as the square sum of a two-phase current obtained by three-phase two-phase converting a current fed to the motor detected by overlapping a high-frequency signal to a d-axis exciting-section current command value is calculated, the square of the amplitude of a command- current vector as the sum of the square of the d-axis exciting-section current command value and the square of a q-axis torque-section current value is computed, and an axis-displacement error angle is calculated, on the basis of a value acquired by subtracting the square of the amplitude of the command- current vector from the square of the amplitude of the detecting-current vector. |
