This work studies how to control the speed of a squirrel‑cage induction motor running with indirect field‑oriented control, using a polynomial RST controller for the speed loop. The proposed controller is constructed in the continuous‑time d q reference frame using three adjustable polynomials and is tuned to improve transient behaviour, robustness to parameter deviations, and sensitivity to measurement imperfections. Particular attention is given to resonance phenomena linked to speed and current sensing, Which helps reduce these effects by shaping the closed‑loop response within the field‑oriented control loop. The continuous‑time control law is implemented on a real‑time digital platform dedicated to induction motor drives, This makes the method practical to use without changing the original modelling approach. A comparison with a conventional PI controller was performed in simulation and through experimental tests. The real-time setup was implemented in MATLAB/Simulink on a dSPACE DS1104 platform, with ControlDesk used for online monitoring and tuning. Overall, the proposed control method showed better reference tracking and stronger disturbance rejection than the PI approach in both simulation and real-time experiments..
Abdelhamid et al. (Fri,) studied this question.