Forecast of Out-of-Step Section in Complicated Power System

Accurately forecasting out-of-step section is very important to the correct action of out-of-step splitting devices. By analyzing the phase-angle difference change feature of branch in different location of network in time of one machine-infinite system losing stability, it is pointed out that out-of-step section only can occur in the middle part of lines between groups or vicinity. For complicated multi-machines system, based on network parameter, by means of coupling thinking, vulnerability location which is inherent in network is identified, then the phase-angle difference change feature of branch in different location is combined in vulnerability location, out-of-step section in complicated multi-machines system network is forecasted. Simulation and analysis on New England 10 machines system testifies the validation of the proposed method.