Mechanism of Low Frequency Oscillation with Multiple Disturbances Based on Stability Region Theory in Wide-area System
Because of the characteristics of disturbances and operations in system,low frequency oscillation in wide area power system always performs multiple disturbances phenomenon,which brings huge challenge to analysis and control.Based on this phenomenon,a model named section power flow analysis is proposed.Based on this model,a practical approach is given to present for getting the energy function and stability region of wide-area power system.Then,a flowchart is presented on how to use stability region theory to analyze the low frequency oscillation with multiple disturbances.This method can be carried out in wide-area power system for on-line real-time security assessment and warning,on this basis some control strategies can be brought out correspondingly.So the controllability,observability of the system will be promoted at a higher level.As a result,a safe,reliable,economic and efficient power system will be secured well.And blackouts incidents caused by power system stability failure can be controlled.Meanwhile,it can improve system reliability.IEEE 4 machines 11 nodes system and Central China Grid system are used for simulation and analysis.At the same time,many results are obtained with different multiple disturbances.And the results verify the correctness andeffectivenessoftheproposedmethod.Thismethodcanbeusedforanalyzing,monitoring,andemergency controlforlow-frequencyoscillationwithmultipledisturbancesinpracticalwide-areasystemwithguidingsignificance.