Load Forecasting And Medium Voltage Distribution Network Planning In Songgang Shenzhen

Load forecasting of distribution network is a fundamental work of electric power system, it determines substation planning, radius of power line, number of power line, trend of power line, power load distribution and other aspects. Accurate load forecasting can ensure the safe and stable operation of distribution network, improve the utilization of power equipment, extend the service life of power equipment, reduce power investment costs, enhance power supply reliability, especially in the power system reform today, load forecasting of distribution network has become more and more important. Compared with the ultra short-term and short-term power load forecasting, medium and long term load forecasting is to point to the load forecasting of more than one year. Due to the long time interval, big change of seasonal load, involving national economic factors, the work is difficult, with the traditional load forecasting model is difficult to meet the precision requirement.In this paper, on the basis of comparative advantages and disadvantages of several kinds of prediction model, choose grey forecasting model. Grey forecasting model has ad vantages of less sample and higher prediction accuracy. First using GM(1, 1) model of grey prediction model to forecast the load during nearly 10 yea rs in Songgang; Then texting the predicted results, model evaluation result is "optimal"; Finally,using GM(1, 1) model to forecast the load in the next five years in Songgang. In order to improve the accuracy and the comparability on the basis of GM(1, 1) model, using the residual improvement model to forecast the load during nearly 10 years in Songgang again. Similarly, texting the predicted results, contrasting the data among the results, finding the improved model is more close to the real value than the GM(1, 1) model. Thus, not only get more accurate power load number in the next five years, but also demonstrate the reliability of the improved model.In Songgang area, there are problems such as the main transformer overload, line overload, reasonable divided grids and so on. After analyzing the existing problems, the scheme is put forward to improve power supply status: First, utilizing grey forecasting model, we get the installed capacity of the three big grids in the next 5 years; Then, we calculate the number of typical connection; Last, depending on the roads, rivers, hills and woods, areas where residents live in, and so on, each large grid is subdivided into a number of small grids.