Research On Differential Programming Model Of Power System Considering The Uncertainty Of Wind Power Generation

In recent years,large-scale blackouts have occurred frequently around the world,and the safe operation of the power grid has attracted widespread attention.Research shows that most of these blackouts are cascading failures caused by partial component failures.At the same time,a lot of new energy sources(like wind power)are connected to the power grid.its randomness and volatility uncertainty bring new challenges to the identification of power grid vulnerable nodes.In the context of the new energy source access,the system operators quickly and accurately assess the vulnerability of nodes in the network,and select the vulnerable nodes in the system.Before the disaster accident,Grid Company strengthens the construction standards for the vulnerable components in the network,and constructs the core backbone that can supply power to vulnerable components under disaster by using the method of differential planning and design.It can improve the level of network disaster reduction.Therefore this paper studies the vulnerability assessment of the power system and the grid differential planning of the vulnerable nodes considering the uncertainty of renewable energy generation,which has a certain guiding significance for the safe operation of the power system.An identification method of vulnerable nodes based on static and dynamic integration of Power Grid Considering the uncertainty of wind power generation is proposed in this paper.In the static identification,consider the uncertainty of wind power,the interval minimum load shedding model based on interval direct current power flow is proposed to calculate the interval static vulnerability assessment indices.This method measure the static vulnerability of the node in terms of the interval load shedding loss of the system after the removal of the node.In the dynamic identification,the energy margin of each node is calculated by the extension method of single machine equivalence(SIME)method for the new energy power supply system,and the dynamic vulnerability assessment index is obtained according to the positive or negative of energy margin.Finally,the weight of two kinds of evaluation method in comprehensive index is obtained based on entropy weight method,and the vulnerability nodes in power grid are identified.The simulation results of IEEE 39-bus system show that the proposed method can accurately and quickly identify the vulnerability nodes under the condition of new energy injected the power grid.Compared with the existing vulnerability identification methods,the proposed method is more in line with actual operation of the power system.Through the research,the randomness and volatility of new energy near influence principle provides guidance for the planning of the new energy power supply in the smart grid.Based on the identification of vulnerable nodes,a network core backbone network search model based on the minimum spanning tree algorithm is established.This model uses the line electric betweenness as the weight of the importance of the lines.The model first determines the vulnerable nodes that need to be reserved in the grid,and verifies the supply and demand balance between the generation capacity and load demand for the vulnerable nodes,and determines whether new power nodes are needed.And then,the shortest path between the vulnerable nodes is calculated by using the line electric betweenness as the weight,and the subgraph of the system topology is formed according to the shortest path.The minimum spanning tree algorithm is used to determine the backbone of the system.The connectivity and security of the backbone network is verified to determine whether the network needs to be adjusted.Finally,the final core backbone is determined.The simulation results of IEEE 39-bus system show that the proposed model can quickly build the core backbone of the system.