Studing power system models for assessment of marginal states

State of the power system exposed to various disturbance: power fluctuation, change in the equipment schedule, network topology, etc. Therefore, in order to ensure reliable operations of the power system, it is necessary to accurately determine the steady state stability limits and limits of existence of the power-flow, i.e. the so-called marginal states of the power system. The article investigates the third-order Park ’s model with the automatic voltage regulator and turbine governor, classical model and standard power-flow model of power system. In the article marginal states of power system models are studied for the case of 3-machine system model. The most suitable model for assessment of the marginal states is determined.