Sliding mode position control of a vector-controlled induction machine with nonlinear load dynamics

In this paper, a solution to the position control problem for a vector controlled induction machine in the presence of nonlinear load friction, is proposed. A sliding mode (SMC) control system using the equivalent control concept and a switching term is designed to compensate for the non-linear load dynamics in the machine. A pseudo sliding technique is incorporated in the switching term design to avoid the main drawback presented by the standard first-order sliding mode control, that is the chattering phenomenon. The control objective is to track a set of reference trajectories such as rotor position and speed. A single component Slotine´s sliding mode (SSM) controller and a fixed gain (FG) controller are designed to compare the controller performance. The designed control system is implemented on a test rig. The experimental results are presented in this paper.