A Finite Difference Model of Linear Induction Motors, Raking into Account the Finite Length of Iron.

The electromagnetic equations of the motor are written, then transformed by the finite difference technique. Both the infinite extent of the secondary and the finite extent of the iron are taken into account by the partition method. Actual width of the iron and the secondary are considered. Most of the unknowns are eleminated by the use of a transmission matrix ; thus, the final system of algebric equations is small enough to be solved by a classical inversion technique. An interesting correspondance is established between the eigenvalues of the transmission matrix and the poles of some expressions which are obtained when Fourier transform technique is used.