A mathematical model of a block power station (PS) with different systems of generator excitation is developed, which enables the instantaneous values of currents and voltages to be calculated for the estimation of the generator dynamic stability and for the choice of the settings of the relay protection and automatic devices. A power station with turbogenerators of 100-800 MW is considered. The modeling is carried out using the full Gorev-Park differential equations for generators, transformers, power lines and electric motors. The rotor massive of asynchronous motors is represented by two equivalent damping circuits in each of the axes α, β. The program in Fortran is realized on IBM PC. The results of calculations are presented for the PS with 200 MW units.