Modelling of vector controlled cage induction motor with FEM

A numerical computation of squirrel cage induction machine parameters is presented using the finite element method (FEM). The effects of main field saturation are studied and the different parameters can be calculated for any magnetising current value. To take into account magnetic state variations, a ‘dynamic’ mutual inductance is introduced into the saturated machine model. All these parameter values are used in the field-oriented control system realisation, and experimental results are described for constant and weakened flux operating points. Special attention is given to the adaptation of the control law during flux-weakening, to take into account desaturation effect. The results obtained are quite satisfactory.