Reliability Analysis Of Power System Based On Large Power Grid Partition

Power system reliability assessment is of great significance for system planning and safe operation.In the current era of rapid development of science and technology,with the gradual interconnection between the construction of UHV power grids and regional power grids,the scale of China's power grids is expanding and the degree of interconnection is constantly improving.Therefore,the problem of safe and reliable operation of the power system has become increasingly prominent,and it has also brought difficulties to reliability assessment.Network scale is one of the main reasons leading to long reliability evaluation.In order to ensure the accuracy of reliability assessment results,it is necessary to propose an appropriate grid zoning strategy.How to partition has become an urgent problem to be solved.This paper aims to improve the computational efficiency of large-scale power grid reliability assessment and to study the method of partitioning.By partitioning the large grids in weakly connected nodes and using network simplification or equivalent methods to calculate the reliability of the grid,the computational complexity can be greatly simplifiedThe research contents of this paper are as follows:(1)Combined with the power system reliability index and electrical median,component physical characteristics,social impact factors and other factors,this paper proposes an improved component comprehensive importance to evaluate the component importance of each component in the power system.This method overcomes the traditional method of focusing only on the topology or focusing only on the electrical connection,and can fully reflect the influence of the component on the system and identify its importance.(2)A new zoning standard for grid zoning in power system reliability assessment is proposed.Based on the strength of the electrical connection between different components in the grid structure,this paper discusses the impact of the single component on the reliability index of other components in the system when it exits the operation.The method of analysis divides the components in the system that have similar laws of change,that is,electrically connected components,into the same area.This method is based on the interaction between components and is closer to the actual situation of reliability calculation.(3)The improved Ward equivalent technology is used for the analysis and processing of the partitioned power system.On this basis,a method of taking the non-parametric kernel density estimation technique to obtain the external network equivalent model is introduced.The Monte Carlo method is used to evaluate the system reliability,analysis.The comprehensive analysis of the power system analysis is ensured by classifying the operation of the grid partition.This method can more effectively study the research part of the power system to be emphasized,and simplify the network structure while ensuring the accuracy of calculation and improving the calculation speed.