Research On Power Grid Node Evaluation Based On Electrical LeaderRank Algorithm

With the continuous expansion of power grid,cascading failure will lead to a huge economic losses.The evaluation of power grid has great benefit in reducing the loss of cascading failure and safety operation of power grid.Therefore,an appropriate power grid node importance evaluation method has significance practical value.Considering the difference between power grid and social network,the existing node importance assessment method need to be improved when evaluating the importance of power grid nodes.The impact brought by renewable energy in power grid is not considered in any existing method.Therefore,how to improve the accuracy of the power grid node importance evaluation method under the premise of considering the impact of renewable energy has become an urgent problem.This paper has studied the problems above.Firstly,this paper proposes an interval cascading failure model considering the uncertainty of wind power.The purpose of this model is to calculate the power grid load loss with wind power connected when the power grid is attacked.This model can simulate the cascading failure procedure and calculate the load loss considering or not considering wind power uncertainty.The load loss calculated by this model is the basic for further work in this paper.Secondly,this paper proposes the electrical LeaderRank method for power grid node evaluation.The proposed method takes the magnitude of the line flow,the load importance of the nodes,the load loss caused by cascading failure into account.This method does not consider the uncertainty of wind power,and it suitable for the evaluation of power grid nodes without wind power penetration.The proposed method is verified among PageRank method,LeaderRank method and electrical Betweenness method.The results show that the accuracy of electrical LeaderRank method in power grid node evaluation is higher than other three methods.Finally,this paper proposes an interval electrical LeaderRank method,which is based on electrical LeaderRank method.The proposed method takes the uncertainty of wind power into consideration.The direct adjacent matrix and the iterative process is modified for the uncertainty of line power flow.The proposed method is compared with electrical LeaderRank method in case study,and the results show that the vulnerability of power grid with wind power penetration is larger than the power grid without wind power penetration.The results of this paper show that electrical LeaderRank method has higher accuracy than electrical Betweenness method in power grid nodes evaluation,and electrical Betweenness method is the most popular method in power grid nodes evaluation.Interval electrical LeaderRank method maintains the accuracy of electrical LeaderRank method,and it verifies that power grid nodes has higher vulnerability in the case of wind power penetration.