Application of the induction motor torque - observer to the control of turbo - machines

This paper describes the results of the experiment with an application of the outer torque observer to the radial fan driven by induction motor fed from the voltage inverter. The observer is designed to be an additional stand-alone device connected between the induction motor and the power supply, separated from the inner signals of the inverter controller. The inputs for the observer algorithm are the three-phase currents and voltages measured in the conductors connected to the motor terminals. The output signals of this observer estimating the stator flux and motor electro-magnetic torque are used to the compressor supervisory control.