Research And Application On Layered Optimization And Network Structure Optimization Of Distribution Network Based On Three-layer Grid

Distribution network planning plays a very important role in the network planning and construction,and is an important prerequisite to ensure the safety,reliability,quality and economy of the network.Based on the three-layer network planning of distribution network,this paper focuses on the layered optimization of distribution network and the optimization of network frame planning under the grid planning process.In the layered optimization,a complete three-layer grid structure of "electricity unit-power supply unit-power supply grid" is presented.In addition,this paper focuses on optimizing the division of the second layer of the three-tier grid.The improvement focuses are as follows:first,this paper adopts the improved k-means clustering algorithm to divide the power supply blocks in the planning area.The grid dynamic reduction method is introduced to determine the initial load center to avoid the problem of traditional k-means relying too much on the initial load center.The load weight factor is introduced to make the load between each power supply block keep relative balance.Secondly,this paper adopts Hungarian algorithm to form power supply unit by matching several adjacent power supply blocks,and the power supply unit obtained has the best interconnection mode.On the basis of previous research on grid planning of distribution network,this paper improves the traditional genetic algorithm used in grid planning of distribution network.Based on the knowledge of graph theory,the improved algorithm USES the spanning tree algorithm to calculate the alternative network as the initial solution.According to the idea of spanning tree algorithm,the unique hybridization operator and mutation operator are designed,so that the network generated by the mutation process and hybridization process is a radial network,and the optimization ability of the algorithm is greatly enhanced.Combined with the simulated annealing operation,the local search ability is strengthened when the convergence speed is slightly reduced,which is more suitable for finding the global optimal solution.In this paper,the distribution network frame planning under the whole life cycle is introduced,considering both economy and reliability,so that the whole benefit can be optimized under the whole life cycle.Finally,taking the high-tech zone of FZ city as an example,the paper applies all the algorithms of grid optimization and grid frame optimization to the distribution network planning problem,and verifies the effectiveness of the algorithm through a practical example.