A Sensorless Flux-Speed Sliding Mode Controller for Induction Motor with Experimental Results

This paper proposes a new flux and speed sliding mode controller for sensorless induction motor. A combined controller and observer design allows, under parametric uncertainties, to achieve the tracking of rotor flux and mechanical speed for induction motor without the need of flux, speed and load torque measurements. Based on Lyapunov theory, firstly the stability of the proposed controller is given. Secondly, the stability of the proposed observer is proved and then the proof of the whole closed-loop system stability "controller+observer" is given under induction motor parametric uncertainties. Furthermore, due to the complexity of observation at low frequencies, the proposed controller using an observer is tested and validated on reference trajectories of a sensorless induction motor control benchmark. This benchmark is applied on an experimental set-up located at IRCCyN (Nantes, France). The applicability of the designed controller is emphasized by the robustness experiment tests with respect to parameters variation of induction motor.