Quasi-Continuous SOSM controller applied to an induction motor with current limitation

In this paper, the authors propose a robust nonlinear controller with high performance and accuracy. The controller is based on a Second Order Sliding Modes technique which is characterized by having Quasi-Continuous control signals. The controlled outputs are the angular velocity and rotor magnetic flux module, including a limiter of start current. The controller incorporates a state observer for estimating the rotor magnetic fluxes, and a robust differentiator for calculating the sliding manifold derivative; therefore, the load torque estimation is not required. The proposed velocity controller involving a rotor flux observer and robust differentiator provides robustness, high performances and accuracy; as is validated by results obtained through simulations in Simulink/MATLAB program.