Two degree of freedom control of IM modeled through discrete lagrangian approch

In this paper speed control of induction motor (IM) with two degree of freedom (DOF) control strategy is addressed in discrete time domain. In order to do so, a novel discrete model of IM in synchronously rotating reference frame is developed with formation of discrete lagrangian. The two DOF controller is designed to meet robustness criteria in terms of gain margin, phase margin and sensitivity function through pole placement technique. The performance of the two DOF control for the discrete lagrangian model is examined for set point tracking and load disturbance rejection. The performance of two DOF control scheme is found to be satisfactory for the considered operating conditions.