Further Developments in State Estimation and Parameter Identification for Efficiency Optimization of Induction Motor Operations

This paper aims, for the first time in the literature, at presenting experimental results, within a suitably devised testing IM (Induction Motor) drive set-up, of the recently designed, theoretically-based, global adaptive IM-observer that exponentially recovers, on the basis of the rotor speed and stator current/voltage measurements, the rotor flux and load torque by achieving an arbitrary rate of convergence. No knowledge of the rotor resistance is required, no direct current injection into the estimates expressions is carried out, no requirements of transition matrices-based conditions (such as regular input persistency) are critically involved in its design. The paper also presents a new global stator resistance and rotor resistance identification procedure that is able to avoid observability/identification issues by complementing, based on the same information, the classical torque-speed characteristics construction procedure. Such a procedure can be originally used: i) to provide the aforementioned adaptive observer with the value of the stator resistance; ii) to catch the rotor resistance value that allows for the identification of the efficiency-optimal rotor flux modulus reference minimizing the power loss at steady-state.