Substation Optimization Planning Based On Weighted Voronoi Diagram

With the rapid development of expansion and reform for urban power systems in China, urban power system planning has become an urgent work. Urban distribution network planning includes several steps such as Load Forecasting, Substation Locating and Sizing, Distribution Network Planning and Reactive Sources Optimal Planning. Among these steps, Substation Locating and Sizing based on Load Forecasting is a complex but important step, because its result will affect many aspects directly such as power line routing, network structure, power network investment, operation economy level and power supply reliability.In substation optimal planning, the number, site, capacity and service region of the new substation are to be caculated, and the relationship of these factors is very complex. Substation optimization planning plays an important role in urban network planning. This paper presents a novel method for substation planning based on weighted Voronoi diagram, which can optimize the quantities, locations, sizes and power supply areas of substation. Firstly, a mathematic model is proposed to get the capacity combinations of new substations, in which the optimum solution and suboptimum solutions can also be obtained simultaneously by integer programming. Then, according to the existence of substations, two methods are adopted to get the initial locations. One is ordinary Voronoi diagram method and the other is geometrical method which can consider local topographic characteristics, area of planning district and load distribution. The uneven load distribution, the different rated capacity and the load rates of each substation can affect the power supply areas seriously. To take account of the affections, a substation optimization method based on weighted Voronoi diagram is proposed to automatically decide the power supply areas of each substation and optimize the locations of new substations.Real examples show that with the similar computing speed, the proposed method has a better substation optimization planning result than traditional substation optimization planning method based on geormetry coordinate, improves the scientificalness and adaptability of substation optimization planning result and can meet the practical planning requirements all the better.