Substation Multi-Stage Planning Based On Improved Weighted Voronoi Diagram

In allusion to the optimal multi-stage substation planning problems in urban network planning, a method based on Improved Weighted Voronoi Diagram and Genetic Algorithm(IWVD-GA) is established to solving substation planning problem in target years, and a method based on Dynamic Programming is produced to solving multi-stage substation planning problems. In IWVD-GA, the weighted voronoi diagram is improved by improving the fixed weight and introducing the variable weight to reflecting more accurately the impact of different types of substation and uneven load distribution on substation power supply division, and the Cellular Automata(CA) is proposed to generating the improved voronoi diagram dynamically, during which the weights can be dynamically adjusted based on the constraints of substation load-rate and power supply radius, and introducing the formulation of the cellular automata local evolution rules, and put forward the evolution step to dividing the weighted voronoi diagram generation process, then improving the efficiency of the algorithm and the process of dividing power supply areas is controllable and more reasonable. The new substation sites and power supply areas divisions are locally optimized in depth by Alternate Location Algorithm(ALA), and globally optimized by Genetic Algorithm(GA). To solving the problem of low speed of CA caused by judging all the cellulars in every evolution process when there are many cellulars, according to the property that the cellular state transitions appear in the expanding boundary, through the judgment of each generating element in the adjacent evolution step in the expansion of the cellular distance, then we need only to determine the cellular which need to be judged, then effectively reducing the cellular number of frequency.we can determine the cellulars which need to be judged, thus reducing the number of cellular judging. Based on the optimization of IWVD-GA algorithm to solving the target year of substation location and capacity, this paper based on the dynamic programming algorithm to solving the optimization problem of multi-stage substation planning. Firstly, based on the IWVD-GA algorithm optimization results of the target year substation location and capacity, put the site as the substation site in each middle years, the main transformer capacity of each intermediate years are subject to the target year, and the main transformer number is no more than the target year. Then not only to meet the target year for optimal planning requirements, but also reducing the number of combinations of various years between candidate location and capacity of substation, then the actual substation planning is continuous in the construction process of a plurality of middle years, avoiding the repeated construction and waste. And then the middle years of planning is divided into several stages, through the establishment of dynamic programming model and according to various technical constraints to be satisfied in the middle years of substation planning, such as the capacity constraints, load-rate constraints and power supply radius constraints, effectively reducing the types of each middle years substation capacity type number; finally, phased construction strategy in substation including the intermediate and the goal year planning time optimal are obtained by solving the dynamic programming model, the substation planning can meet the load requirements and related technical constraints in each planning period, giving the new substation and the existing substation construction scheme, which is in line with the actual needs of the actual substation project long-term construction. The results show the efficiency of the proposed method in target year substation optimal planning problems and multi-stage substation optimization planning problems.