Research On Cascading Failures Model In Small World Grid Based On Power Flow Betweenness And UPFC

With expansion of the scale and increasing complexity of the structure, Power gridhas become one of the largest and most complex artificial systems in the world. Inrecent years, a series of cascading blackouts due to a chain reaction triggered by singlefault have occurred frequently, that fully exposed the vulnerability of largeinterconnecting power grid. Small world network theory has provided an effective wayto study the overall dynamic characteristics of large interconnecting power grid. On thebasis of existing models, this paper is established in the research of cascading failuremodel based on small world network theory, and its mainly contents are as follows:①Aiming at the shortcomings of the existing fault indexes in the models ofcascading failure in small world grid, combining the reality of power system, and basedon the optimal load cutting model, Minimum load loss percentage is proposed as a newmeasurement of cascading failure.②I n-depth analysis the characteristics of existing indexes which are themeasurement of key nodes in the network, based on the distribution of power flow inactual power grid, power flow betweenness is proposed which offsets the deficiencies ofweighted betweenness and electric betweenness, reflects the role of each node played inpower propagation of the grid, and affection of factors such as reactive power andvoltage indirectly. Based on the cascading failure with electric betweenness in smallworld gird, a model with power flow betweenness is proposed, and AC optimal loadcurtailment-based minimum loss load percentage is applied to evaluate the extent offailure.③In the power flow betweenness-based cascading failure model, UPFC isintroduced to replaced the regulation means of the existing model, and use minimumloss load percentage based on AC optimal load cutting model considering UPFC asfailure index, then power flow betweenness and UPFC-based cascading failure model isproposed. Meanwhile a power flow betweenness-based UPFC location optimizationstrategy is proposed.④Based on Matlab programming environment, the algorithm of the model isrealized. The correction and validity of the method is confirmed by the simulationresults of IEEE39bus test system.