Research On Urban Power Grid Partitioning Method Based On Equivalent Modeling And Load Classification

The rapid development of cities makes the demand for electricity continue to expand,but the construction and development speed of urban power grids often lags behind the construction speed of cities,and the operation status of power grids is not optimistic.The continuous expansion of the scale of urban power grids has made the operation of power grids more and more complicated.The main manifestations are that the system short-circuit current increases or even exceeds the rated short-circuit current,and the risk of large-scale power outages increases.Therefore,based on the existing conditions,reducing the short-circuit current,improving the power grid operation environment and improving the safe operation of the power grid are important issues in the development of the urban power grid.Grid partitioning can simplify the grid structure,reduce the calculation order of the grid,limit the short-circuit current and so on.For the urban power grid,partitioning operation can solve or alleviate the current problems to a certain extent.The current research on power grid partitioning rarely takes into account the two characteristics of the complex structure of the urban power grid and the wide variety of loads.Therefore,based on the equivalent modeling and load classification analysis of the urban power grid,this paper studies the urban power grid partitioning method and the evaluation method of the partitioning scheme.The research contents mainly include:(1)Research on urban power grid equivalent modeling and load classification methods.The structure of the urban power grid is complex,and it is difficult to simulate the entire network.Therefore,the hierarchical multi-step dynamic equivalence modeling method is used to perform the equivalence on the external network of the urban power grid to reduce the calculation difficulty and improve the efficiency.In addition,there are many types of urban power grid loads,and different types of loads have different requirements on power supply reliability.This paper uses load classification to ensure the power supply requirements of important loads in the partitioning process.A real urban power grid case verifies the effectiveness of the equivalent method and analyze the load of the power grid(2)Research on urban power grid partitioning method.After the simplification of equivalence,the calculation and analysis difficulty of the urban power grid is reduced,and the equivalence accuracy meets the calculation requirements.On this basis,this paper proposes a method of partitioning the urban power grid considering load classification.Firstly,the basic principles of power grid partitioning are determined,and then the urban power grid partitioning mathematical model considering load classification is proposed,and a hybridization of multi-objective particle swarm optimization and simulated annealing algorithm is used to solve this problem.Applying this method in a real urban power grid in the east of my country,a partitioning scheme is obtained(3)Research on evaluation method of urban power grid partitioning schemes.It is difficult to evaluate the merits and demerits of the partitioning scheme with a single index.In order to comprehensively evaluate the zoning method of the urban power grid,a scoring optimization method based on multi-index evaluation is proposed.According to grid operation requirements and partitioning objectives,the evaluation indexes of urban power grid partitioning schemes are selected and studied,and then the urban power grid partitioning scheme evaluation system is constructed based on the analytic hierarchy process,and the partitioning schemes are quantitatively evaluated.Finally,the comparison and verification results show that the proposed partitioning scheme has the best comprehensive performance,which proves the practicality and effectiveness of the proposed partitioning method.