| 摘要 |
PROBLEM TO BE SOLVED: To automatically measure inductance in a synchronous motor control device which has no magnetic-pole position detector. SOLUTION: This device is provided with an oscillator 1, that impresses an AC voltage in a direction parallel to a dc shaft that rotates at an arbitrary frequency taking an armature current and a terminal voltage as vector; a current detector 4 and a coordinate changer 5 for detecting a dc shaft current; a high-frequency detection filter 7, that detects an AC current of the same frequency with that of the AC voltage from the dc shaft current; detectors 8, 9 that detects the maximum and minimum values of the AC current during a period, when the dc shaft turns by 180 degrees or more of the electrical angle; a computer 10 that computes direct-axis inductance from the maximum value of the AC voltage and the AC current; and a computer 11 that computes quadrature-axis inductance from the minimum value of the AC voltage and the AC current. |
