Reactive Power Planning Of Urban Middle-Voltage Distribution Network

With rapid development of China's power network construction, scientific and reasonable power system planning has become an urgent task. Power network planning includes several steps such as Load Forecasting, Substation Locating and sizing, Distribution Network Planning and Reactive Sources Optimal Planning, and Reactive Sources Optimal Planning is a complex and important step. Based on the result of load forecasting and grid structure of power network, Reactive Sources Optimal Planning solves the location and capacity of reactive source, whose result has a direct impact on voltage quality and operation economy of power system in the future.Amid for distribution power network, solution of distribution reactive source optimal planning refers to hundreds of variables, uneven load distribution and scattered locations of reactive compensation equipments, with all variables having the impact and constraint on each others. Against with the difficulties, this paper presents a novel solution of typical region application for distribution power network, which is based on the thinking of"whole-part-whole".Under the substation load structure mix and substation owned line types, categorize all the substations in the whole distribution network, and select typical substation having most representative features with each categories as an analysis objects. By solving the reactive configuration of typical substation, the solution extends the result to the entire distribution network based on certain principles. Eventually, the reactive configuration of entire distribution network will be identified. Next, the paper presents different method for different aspects of typical region application. First, based on the fuzzy c-means clustering method for substation load structure mix and internal classification method for substation owned mix numbers of cable, the entire distribution network is divided into several typical regions, eventually determining the typical substation in every typical region. Secondly, in the process of solutions of typical substations, combining heuristic optimization method with mathematical optimization method, it determines the location of line reactive compensation. Then using PSO algorithm, make sure all the typical substation reactive configuration. Ultimately, according to various reactive substation configuration, extending the result to the entire region and even the entire distribution network reactive configurations.As the detailed examples and the result show: the capacity of each substation's reactive configuration refers not only to the capacity of the station,line types, but also to the load quality and load size. To some extent, it demonstrates the method of typical region application reasonable and scientific.