FEEDBACK-CONTROL FOR THE DISCRETE NONLINEAR MODEL OF INDUCTION-MOTOR DRIVES

An investigation is made of the stability for the discrete control of drives using a frequency induction motor as an actuator. The approach proposed is based on the choice of a particular model of the discretized system which is non-linear in the state and linear in the control. Because the model parameters depend only on the value of the slip angular frequency, the stabilizing control law is obtained by considering the non-linear time-invariant system as a linear time-varying one. As a consequence, the feedback control is a linear function of the state variables with coefficients depending on the actual values of the time-varying system parameters. The difficulty for computing these coefficients in line is overcome by proposing a suitable choice of constant feedback coefficients, which, for the case of the induction motor, give very efficient and satisfactory results. © 1990 Taylor & Francis Group, LLC.