1. A risk early warning method for security and stability control of load-intensive urban power grids, which is characterized by comprising:
Acquire that states of all the component in the current urban power grid topology structure, and judging whether there is a component fault in the station, if so, firstly carrying out the topology analysis of the plant and the station, and then carrying out the topology analysis of the system to identify mutually isolated subsystems; If it does not exist, directly analyze the system topology;
Calculate the power flow of each subsystem, call the optimal power flow program to simulate the rescheduling process of the power system, calculate the minimum unsatisfied power for the subsystems whose power flow does not converge or the components exceed the limit, analyze all subsystems to obtain the risk measurement index values of each subsystem, and then calculate the risk measurement index values of all subsystems as the risk measurement index values of the urban power grid;
According to the comparison between the risk measurement index value and the set risk measurement index threshold, the corresponding early warning is given to the urban power grid to control the stable operation of the urban power grid.
2. The risk early warning method for the security and stability control of the load-intensive urban power grid according to claim 1, characterized in that in the process of topological analysis of power plants and stations, the switching states of each power plant and station are read, and an association matrix of power plants and stations is formed according to the topological structures of the power plants and stations;
Determine the logical nodes in the plant and station, record the mapping relationship among electrical nodes, logical nodes and system nodes, and form a node mapping table until the topology analysis of all plants and stations is completed.
3. The risk early warning method for security and stability control of load-intensive urban power grid according to claim 2, characterized in that the transitive closure matrix of the topological structure of power plants and stations is obtained by Gaussian elimination calculation, and the node connectivity table of the transitive closure matrix is searched to determine the logical nodes in the power plants and stations.
4. The risk early warning method for security and stability control of load-intensive urban power grid according to claim 1, characterized in that in the process of system topology analysis, the network topology structure and its correlation matrix are formed according to the power station and node information at both ends of the transmission line;
Analyze the network topology and determine the subsystems in the power grid.
5. The risk early warning method for security and stability control of load-intensive urban power grid according to claim 4, characterized in that in the process of analyzing the network topology, logical nodes in the network topology are determined, and the mapping relationships among electrical nodes, logical nodes and system nodes are recorded to form a corresponding node mapping table.
6. The risk early warning method for the security and stability control of the load-intensive urban power grid according to claim 1, characterized in that the risk measurement index value of the subsystem is: by sampling the duration of the random state, the states of all components in each time period in the analysis period are obtained, and the corresponding occurrence probability is obtained for the system operation state in each time period.
7. The risk early warning method for security and stability control of load-intensive urban power grid according to claim 1, characterized in that the risk early warning method for security and stability control of load-intensive urban power grid further comprises:
According to the risk measurement index value, the operation state of urban power grid is determined, so that the corresponding decisions in the decision base can be retrieved and the preventive control or emergency control of urban power grid can be realized.
8. A risk early warning system for security and stability control of load-intensive urban power grids, comprising:
The topology analysis module is use for acquiring that state of all components in the current urban power grid topology structure, judging whet there is a component fault in the station, and if so, firstly carrying out topology analysis of the plant and the station, and then carrying out system topology analysis to identify mutually isolated subsystems; If it does not exist, directly analyze the system topology;
The risk measurement index value calculation module is used for respectively calculating the power flow of each subsystem, calling the optimal power flow program for the subsystems whose power flow is not convergent or whose components exceed the limit, simulating the rescheduling process of the power system, calculating the minimum unsatisfied power, analyzing all subsystems to obtain the risk measurement index value of each subsystem, and calculating the risk measurement index value of all subsystems as the risk measurement index value of the urban power grid;
And the risk early warning module is used for giving corresponding early warning to the urban power grid according to the comparison between the risk measurement index value and the set risk measurement index threshold value, so as to control the stable operation of the urban power grid.
9. A computer-readable storage medium storing a computer program, wherein the program, when executed by a processor, realizes the steps in the risk early warning method for security and stability control of load-intensive urban power grids according to claim 1-7.
10. A computer device includes a memory, a processor and a computer program stored in the memory and running on the processor, characterized in that when the processor executes the program, the steps in the risk early warning method for security and stability control of load-intensive urban power grids described in any one of claims 1-7 are realized.
Technical summary
The invention belongs to the field of power grid risk early warning, and provides a risk early warning method and system for safety and stability control of load-intensive urban power grids. The risk early warning method for the safety and stability control of the load-intensive urban power grid includes the following steps: obtaining the states of all components in the current urban power grid topology structure, and judging whether there is a component fault in the station, if so, firstly carrying out the topology analysis of the plant and the station, and then carrying out the system topology analysis to identify mutually isolated subsystems; If it does not exist, directly analyze the system topology; Calculate the power flow of each subsystem, call the optimal power flow program to simulate the rescheduling process of the power system, calculate the minimum unsatisfied power for the subsystems whose power flow does not converge or the components exceed the limit, analyze all subsystems to obtain the risk measurement index values of each subsystem, and then calculate the risk measurement index values of all subsystems as the risk measurement index values of the urban power grid; According to the comparison between the risk measurement index value and the set risk measurement index threshold, the corresponding early warning is given to the urban power grid to control the stable operation of the urban power grid.
R&D technicians: Bloomberg; Guo; Qiu Jifu; Chen Ming; Wei Zhen; An Shuhuai; Wan fayao; Luan Pengchun; Guo Desheng
Protected technical users: State Grid Shandong Electric Power Company Qingdao Power Supply Company; State Grid Corporation Limited
Technology research and development day: 2020. 12.438+0
Technology release date: 202 1.04.30