Robust decoupled control of direct field-oriented induction motor drive

This study focuses on the development of a decoupling mechanism based on total sliding-mode control (TSMC) theory for a direct rotor field orientated (DRFO) induction motor (IM). First, a robust decoupling mechanism including an adaptive flux observer and a sliding-mode current estimator is investigated to decouple the complicated flux and torque dynamics of an IM. Moreover, the acquired flux angle is utilized for the DRFO object such that the dynamic behavior of the IM is like that of a separately excited DC motor. This strategy is derived in the sense of Lyapunov stability theorem such that the stable decoupling performance can be ensured under the occurrence of system uncertainties. In addition, numerical simulations as well as experimental results are provided to validate the effectiveness of the developed methodology in comparison with a model reference adaptive system (MRAS) flux observer.