Patent ID: 6611124
Filing Date: 2003-08-26
Classification: H02P

Abstract:
A control apparatus of an induction motor, comprising:a detector for detecting a primary current of the induction motor; primary current component detecting means for detecting an exciting current and a torque current from the current detected by the detector; correcting means for outputting a correction voltage to set to zero a difference between an exciting current command value and the exciting current outputted from the primary current detecting means; frequency-voltage control means for outputting a frequency command and a voltage command based on an output of the correcting means, and an inductance ratio of the induction motor, the inductance ratio being a ratio of a mutual inductance of the inductance motor to a secondary self-inductance of the induction motor; and constant correcting means for correcting the inductance ratio used by the frequency-voltage control means to set to zero the output of the correcting means; wherein the frequency-voltage control means outputs a frequency command and a voltage command based on a constant obtained from a primary resistance of the induction motor, the inductance ratio of the induction motor, a leakage inductance of the induction motor, and a preset value; and wherein the constant correcting means corrects the constant.