In the present work, it is studied by simulation the dinamic behavior of a power system,constituted by two interconnected areas, in case of getting lost the power generation in one of two areas, by the use of technics in state variables and considering some non linearity of the system. Starting in the system representative model, [2], under non linear treatment, we can get a collection of equations that, if represented in the state space, will allow the analyse of its behavior. The model that include the controller of the integral type, which objective is to keep the generated frequency in 60 Hz, is of the order 12, that, after considerations of simplifyting nature, is reduced to the order six. The next step is to determine the balanced points of the system and by using the Liapunov`s theorem of the local stability, will be analysed the nature (Kind) of them. As the last step of the work, was made the simulation of the system global model using a digital computer and considering some types of generation lost situations, defining the areas by the use of different parameters and the results are shown graphically.