Choice of a numerical differentiation formula in detailed equivalent circuits models of linear induction motors

The article describes a mathematical model of a linear induction motor on the basis of detailed equivalent circuits. This model performs calculations of both electromagnetic steady-states and transients in LIM, has considerably fewer degrees of freedom than the FEM-based models, which is especially important when performing optimization calculations, designing, and analyzing dynamic modes. In this paper we investigate the effect of the numerical differentiation algorithm on the LIM calculation results on the basis of the detailed equivalent circuits models (DECM). It is shown that the use of the numerical differentiation formulas that provide a more correct result approximates significantly the DEC-based calculations to the FEM-based calculations.