| 摘要 |
PURPOSE: To measure the transfer function by a simpler method than conventional ones of the magnetic flux characteristic of a synchronous motor having lump-form magnetic poles, by making the method include a direct-axis impedance measuring procedure, a direct-axis characteristic presuming procedure whereby it is presumed that the direct-axis impedance has a specific value in its gain slope characteristic and is equal to its direc-axis synchronous inductance measured from its direct-axis synchronous reactance at an enough low frequency, and a gain calculating procedure. CONSTITUTION: First, a frequency fHz lower than the cut-off frequency of the armature-current controlling system so predetermined as to control a synchronous motor to be a measurement object whereat also eddy currents are induced remarkably in the lump-form magnetic poles of the synchronous motor is determined (ST11). Then, the field-open direct-axis impedance of the synchronous motor at the frequency fHz is measured (ST12). From the direct-axis impedance, a gain (A) of its frequency characteristic curve is measured at the frequency fHz, and it is presumed that its gain characteristic in the vicinity of the frequency fHz is -8--10dB/dec (ST13, 14). Also, a direct-axis synchronous reactance Xd of the synchronous motor is measured, and thereby, a direct-axis synchronous inductance Ld thereof is determined, and it is presumed that the inductance Ld is the gain of the direct-axis impedance at an enough lower frequency than the frequency fHz (ST15-17). From the foregoing procedures, the frequency characteristic of the direct-axis impedance is determined (ST18). |
