Patent ID: 8736222

Claim:
A flux controller for an induction motor using a sensorless vector control method, comprising: a velocity controller for receiving a difference in velocity between a velocity command and an estimated velocity to output a torque current command; a torque current controller for receiving the torque current command to output a torque voltage command; a flux controller for receiving a difference in flux between a flux command and an estimated flux value to output a flux current command; a flux current controller for receiving the flux current command to output a flux voltage command; a three-phase converter for converting the torque voltage command and the flux voltage command into a three-phase voltage command applied to the induction motor to output the three-phase voltage command; a flux estimator for receiving a three-phase current of the induction motor, the torque voltage command and the flux voltage command to output a rotating angle of a rotor of the induction motor, an estimated flux value of the rotor and an estimated velocity of the rotor; and a flux regulator for receiving the torque voltage command and the estimated velocity to output a gain value that regulates a magnitude of the flux command, wherein the flux regulator increases the magnitude of the flux command when a rotating velocity of the rotor is low.