Robust speed identification for speed sensorless vector control of current-fed double-star induction machine

This paper describes a method to estimate the speed of a double-star induction motor (DSIM) from measured terminal voltages and currents. The synthesis procedure of the estimator is based on the model reference adaptive system theory (MRAS). Hence, the proposed approach is based on observing the instantaneous reactive power of the motor. The estimated rotor speed is then used as feedback in an indirect field-oriented control system (FOC) employing an adaptive rotor resistance estimator. The validity of the method is verified by simulating a 20 kW DSIM.