Dither frequency effects on extremum seeking control-based induction motor parameter estimation

A new induction motor (IM) rotor resistance estimator based on a perturbation-based extremum seeking control (ESC) is proposed. Since implementations of field-oriented control requires accurate values of IM parameters, such as rotor time constant, so, accurate and robust on-line estimations of such parameters are crucial for any modern industrial IM drives. Since dither signal frequency has significant effect on transient response and convergence time, so, selection of this frequency is a big challenge in accurate and fast parameter estimation. A comparison has been made to show the effect of dither signal frequency in parameter identification transient and convergence time. Meanwhile, since extremum seeking control is a model-free approach, so, it is robust against other induction motor parameter variations. The feasibility and effectiveness of the IM rotor time constant estimation by using ESC scheme have been verified by simulation and experimental results. A 2.2 kW experimental prototype has been implemented.