Research On Urban Power Grid Aided Planning System Based On WebGIS

Urban power grid planning is a complicated system, with numerous volume of data and elements of uncertainty, wide areas, and rapid change of update. Such complexity makes past experience of the planners unable to meet the requirements of practical work. Geographic Information System (GIS) is of a powerful information processing capabilities, spatial analysis and visual display capabilities. We use GIS to manage spatial data and attribute data needed displaying directly in front of planners to enhance the planning process interaction. According to GIS spatial analysis, resource allocation and best path selection capability, we can decrease the search space to be optimized and the planning process, and support planners to exclude the mountains, rivers and other suitable location beneficially choosing the substation sites and line corridor conveniently, which enables the planning results more realistic . Therefore, integration of the GIS and urban power grid planning not only reduces the intensity of planning the work of designers, but also improves the overall level of scientific decision-making of power grid planning. These are important academic value and practical significance for the development of power grid.On the basis of analyzing characteristics and content of the urban grid planning, combined with computer technology, information technology, communications technology, this paper constructs a WebGIS decision support system for urban power grid applying to object-oriented programming pattern and GIS components, analyzes the implementation of the principle of the system, and designs the overall structure of the system including the physical architecture design, logical architecture design, system functional design and spatial database design. In the article we focus on the design of the auxiliary function module, and building the mathematical model of load forecasting, substation sitting, and transmission line optimization. We obtain the solutions via gray system theory and particle swarm optimization algorithm, and illustrate design process and solution process in detail. We also verify the correctness of the results and scientific of the results through the planning example. Transmission line optimization is the focal point of this paper. Combining with the actual situation of power grid, we build the mathematical models with the constraints that power grid security and stability and the objective function that minimum of investment costs, operating costs, and cover area. Then we employ particle swarm optimization algorithm to solve planning. This paper introduces the boundary search strategy into particle swarm algorithm and applies it to power grid planning under consideration of security boundary condition that whether each transmission line is overloading or not, so that each particle searches the results close to the border. Examples verify that particles'convergence is faster and the planning procedure better.This designed system, using advanced planning theory and planning methods as a guide, based on GIS technology, combining with present information systems of Power Supply, makes some contribution to the distribution automation and the improvement of the power management level and production efficiency, and supports the electric power industry information construction.