A Recursive Least-Squares Method for the Real-Time Parameter Estimation in Adjustable-Speed Induction Motor Drives

This paper presents the application of a recursive least-squares (RLS) method for real-time parameter estimation in Field-Oriented-Controlled (FOC) and Direct-Torque-Controlled (DTC) electrical drives with an induction motor. An adaptive algorithm is presented which computes either all the parameters in speed transients or only the most critical parameter (rotor time constant in FOC and stator resistance in DTC) in speed steady-state. It is highlighted how the identification scheme can be used, with very few variations, for both control strategies so as to be very desirable at an industrial level. Furthermore simulation results show the capability of the algorithm to track any variation of the parameters under various conditions.