Optimal control of the torque of solid iron rotor induction motor

The optimal control of an asynchronous motor with a solid iron rotor is considered. The objective of the 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 nonlinear 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