Method Development of Speed Control of DC Drive on Basis of Its Feedback Linearization

Abstract

A problem of structural parametric synthesis of a control system of a separately excited DC motor is solved in this research. The method of feedback linearization (inverse dynamics) is used to do that. According to it, a control action value from a speed loop regulator is substituted with a pseudo-control, which is calculated as a sum of a higher derivative of a reference model and a linear compensator outputs. The DC motor and an armature current loop are considered as a generalized control object, which is then linearized. Using the second Lyapunov method, the stability of the control system, which is a result of such synthesis, is analyzed. The proposed control system is compared with a classical cascade control scheme, which speed regulator parameters are calculated in accordance with a symmetrical optimum method. Considering such requirement as keeping the desired transients quality under conditions of the drive non-stationarity and external disturbances, the conducted experiments with the DC motor and its mathematical model show the efficiency of the proposed control system. In particular, rejecting disturbances, the value of the maximum speed control error is reduced, averagely, by 3,79%. As a result, the control system, which can be effectively used as an alternative to the conventional speed PI-controller in the DC drive cascade control scheme, is developed.