OPTIMAL-CONTROL OF THE TORQUE OF SOLID IRON ROTOR INDUCTION-MOTOR

The subject of this paper is the optimal control of an asynchronous motor with a solid iron rotor. The objective of control is to obtain a given torque in minimum time with, naturally, constraints on currents. The idea is to use a model formulated in terms of the potentials of the electromagnetic field, whose evolutions are described by a non linear diffusion equation, in order to determine the domain of validity of the classical techniques of field oriented control. Equations are approximated via a finite element formulation which leads to a finite dimensional dynamical system to which the techniques of optimal control may be applied. The criterion is a norm of the difference between the electromagnetic torque and a given reference torque.