Research Of Power Grid Node Evaluation Based On Improved HITs Algorithm

The interconnection between power systems makes the blackouts wider and the economic losses bigger.Most blackouts are caused by cascading failures,and some vulnerable links in the power grid play a role in the expansion of cascading failures.The importance evaluation of power grid nodes is significant for differentiated planning and management,safe and stable operation of power grid,and reducing the probability of blackouts.The existing algorithms for evaluating the importance of node are mostly from the angle of the topology of the power grid,the physical characteristics of the grid are consider less,and there is also not an algorithm that considers the impact of the node voltage stability on the evaluation of the importance of the grid nodes.In view of the above problems,this article has carried on the corresponding research.In the light of the uncertainty for wind power output,a cascading failure model has been proposed,which can simulate the cascading failures of the power grid connected to wind power and its output is uncertain.The wind power output is represented by an interval number,and the interval optimal power flow problem is transformed into two general optimal power flow problems Using this model.to simulate the self-organized criticality of power grid under different wind power penetration power,and the higher the penetration power of wind power is,the higher the probability of large-scale cascading failure is.This model can simulates the operation state of the power grid after nodes being attacked,and calculates the possible load loss.The calculated load loss is one of the important considerations in the second chapter and the third chapter when evaluating the importance of power grid nodes.In the light of similarities and differences between the electrical characteristics of the power grid.and the Internet characteristics,in this paper,the HITs(Hyperlink-Induced Topic Search)algorithm used in the Internet field is improved when apply it to evaluate the node importance of the grid.The HITs algorithm takes into account both the authority of the node and the hubs of node in the transmission of network information flow,so that it is easy to consider more electrical characteristics of the grid.The algorithm and the PageRank algorithm,the LeaderRank algorithm and the EBT algorithm are applied to the IEEE118 node system.The simulation results show that the node withdrawal from the proposed algorithm will have a greater impact on the average load loss,-the maximum support load,the transmission efficiency of the power grid and the System connectivity index.It is proved that the algorithm has a better identification effect.Considering node voltage collapse is one of the reasons for triggering blackouts.Node voltage stability is a factor worth to consider when evaluating node importance.On the basis of the third chapter,the HITs algorithm which considers node voltage stability is proposed,and the node voltage stability index is used to participate in the iteration of the node authority value.This algorithm and the algorithm proposed in the third chapter are applied to the IEEE118 node system.The simulation results show that this algorithm considers the electrical factors more comprehensive and the evaluation results are more accurate and reasonable.