Research And Practice On Planning Strategies Of Urban Medium And Low Voltage Distribution Network

Urban medium and low voltage distribution network planning is an importantpart of the city’s economic and social development, and it has great significance forensuring the technical rationality of construction projects and improving theeconomic efficiency. In the early construction, due to the lack of investment, theconstruction of urban medium and low voltage distribution network was relativelyslow, lagging behind the development of the city. Meanwhile its construction had notunified planning, which was based on requirements of users. Owing to thesehistorical reasons, irrational structure, capacity shortage and low level automationproblems exist in present medium and low voltage distribution network, which willbe more serious with the growing of load. Therefore, the planning and constructionof medium and low voltage distribution network is imperative. Setting the urbanmedium and low voltage distribution network of Y as an example, the article carriesout research as following:Firstly, in the study of the basic work of planning-load forecasting, a new loadforecasting method based on the combination of extreme learning machine and grayequip-dimensional model is proposed. Based on the advantages of gray system and anew neural network (ELM neural network), the forecasting result of gay is inputtedto the ELM neural network with the main influencing factors of load demand.Therefore, the method not only considers the non-linear relationship between loaddemand and the influencing factors, moreover it takes the time continuity of loadinto account. The experiments show that the method can improve the predictionaccuracy, therefore it is feasible for mid-long term load forecasting.Next, two plan strategies for developing planning and construction programsare researched:1)For the problem of limited investment and lots of problems in theurban distribution network, a strategy for determining the transformation order ofmedium voltage lines is proposed based on AHP is proposed. The method calculatesthe value of the transformation necessity degree of the line, under funds restriction,determines the transformation order according to the size of the value. It makes thedecision of the order of distribution network problem transformation morereasonable.2)A strategy for determining optimal construction and renovationprograms, which has a guiding significance for planning programs. Then, the recent design of urban medium and low voltage distribution networkof Y planning based on current problems and planning strategies is proposed. Finally,evaluation results show that all of technical indicators have reached the goal and theplanning design proposed will greatly improve the urban medium and low voltagedistribution network of Y. In addition, the article also put forward constructivesuggestions that will contribute to the implementation of the planning and furtherimprovement of urban distribution network of Y.The full article carries on practice and research on medium and low voltagedistribution network planning in urban, and the idea and results can providereferences for other cities’ distribution network planning.