Speed identification for deadbeat rotor flux level control of double-star induction machine

The proposed work consists of two parts: (1) developing a method to estimate the speed of the double-star induction motor (DSIM) from measured terminal currents and (2) derivation of a deadbeat rotor flux level control. The synthesis procedure of the estimator is based on the model reference adaptive system theory (MRAS). The proposed scheme uses the instantaneous reactive power of the motor. The estimated rotor speed is then used as feedback in an indirect field-oriented control system (IFOC). The deadbeat rotor flux level control was extended to a DSIM drive to satisfy the change of the rotor flux level in accordance with the load torque. Good results are obtained with this method without sacrificing dynamic performance compared to a constant rotor flux approach. The association of an extended Kalman filter (EKF) has been examined to observe the motor state variables including the rotor flux and the rotor resistance. The identification of the rotor resistance improves robustness of vector control. The principles and the fundamental characteristics of the system are presented and discussed on the basis of simulation results.