Robust chattering-free (higher order) sliding mode control for a vector-controlled induction machine

The chattering behaviour that is inherent in standard sliding mode control is often an obstacle for practical application if neglected. In this paper, special attention is given to a particular chattering-free control method: 2-sliding "super twisting" control algorithm. Several control algorithms, including the standard and chattering-free control algorithms, are assessed via position and speed control of a vector-controlled induction machine. Attention has also been paid to the friction dynamics in the induction machine system. Linear and non-linear friction dynamics in the induction machine model are considered. Simulation results using an induction machine model are first reported, followed by implementation results. A pre-defined reference signal is employed for tracking capability assessment as well as robustness against a high inertia load (about double the machine inertia) and DC motor load.