Currently Matlab/Simulink(R) is the most used simulation tool for the dynamic systems. Modeling of large dynamic systems e.g. wind energy conversion systems implies a wide range of blocks as wind model, turbine model, generator model, power electronics model, transformer and grid model. These blocks implement differential equations of the models and. requires different simulation steps. The electrical generator and the power converter have the smallest simulation step and therefore, these blocks determine the simulation speed. This paper will present important aspects regarding the different implementations of induction machine model and how can be increase the simulation speed can be increased. The application is simulation of a wind turbine.