A Sensorless Vector Control of the Saturated Induction Motor Using Third Harmonic Voltage

초록

A compensation method of the inductance and the stator resistance variations for the speed sensorless control of a saturated induction motor using third harmonic voltages is presented. The saturated air-gap flux of the induction motor contains the space harmonic components rotating synchronous frequency. The dominant third harmonic voltage, as a saturation function of the air-gap flux is used to compensate the nonlinear variations of the mutual inductance depending on the saturation level of the motor. The amplitude and the phase angle of the space harmonic voltage are measured by using a new method of measurement and compensation scheme. Under the saturation condition, the rotor flux observer for the speed sensorless control is designed using the proposed motor parameter adaptation scheme. The validity of the speed sensorless control using the proposed compensation scheme is verified by simulation results.