Approaches And Methods For Evaluation Of Vulnerability Of Power Transmission Grid Caused By Flow Transfer

With the development of transmission network system, power grid outage accidentscaused by power grid cascading failure becomes more and more serious.Unfortunately,regarding the faulty chain in power grid, there does not any model that is recognized in theindusty.Therefore, finding more reasonable criterion for evaluation and building betterevaluation systems becomes the core work for today’s power engineers.In view of the power system chain overload phenomenon, this paper demonstrates theprocess of power grid chain overload and proposes the evaluation method of the gridvulnerability for different initial failure.The paper illustrates the model of dc method andthe chain overload model in details, and as the consequence an model of the tidal transfermodel of the grid under the branch open circuit failure is obtained.Based on these,thispaper explores the area from three aspects and achieved related result.First of all, thebranch transmission power sensitivity of the node power injection is analyzed according tothe relationship between the branch of transmission power and the node power injectionwhen the trend of the transfer occurred.Considering dynamic measurement technology andsecondary cascading failure power grid, from the aspect of branch power than thermalstability limit, combined with relay protection contact failure, dynamic vulnerabilityevaluation method is proposed.Finally, according to the relationship between trend of thetransfer and the branch power limits,on the basis of reflecting the transmissionperformance of system global efficiency criterion,this paper creates a fragile regionpartition method based on clustering algorithm.This provides the grid cascading failure ofprevention and control with theoretical basis and feasibility.In this paper,by combining the theoretical analysis and simulation research,evaluation method is proposed for different initial faults.As a result,a contribution is madeto the area of building cascading failure model.This also provides the construction of thesecure and robust intelligent power grid with theoretical support.