Study On The Practial Methods Of MV Distribution Network Planning

Medium voltage (MV) distribution network planning involves spatial loadforecasting, medium voltage distribution power planning (namely high voltagesubstation planning), medium voltage distribution network load points planning(namely distribution transform planning), feeders’ paths planning and the others (suchas reactive power compensation). Based on the actual practice of distribution networkplanning, spatial load forecasting, load point recongnition for target years and feeders’paths planning are studied in this paper.Spatial load forecasting is the prediction of locations、quantity and generation timeof load growth in future. In this paper, a complete set of classification and subareaapproaches for spatial load forecasting are proposed, considering the disequilibrium ofload development for different areas. Firstly, based on the available data in practice, cityareas may be classified into five kinds: existing areas with known historical loads;existing areas with only their service years being known; existing areas of no data; newareas with starting years and new areas without starting years, which are respectivelyforecasted using different approaches. The template method and location meritindexes/weight coefficients method are employed to handle existing areas with onlyservice years being known and new areas without starting years respectively, and thelatter method is improved. According to the temporal order of new area building, loadforecasting of new area in some a year is obtained via Vacant Area Inference based onthe load forecasting curve of the previous year. The results of study cases show that:compared with the existing methods, the proposed method can make full use of theavailable data in practice and improve the prediction accuracy effectively with the loadforecasting reflecting the temporal relationship and disequilibrium.At present, the spatial load forecasting is commonly used for city grid planningwith land usage information. However, along with the new rural construction planning,rural load concentration increases. In the paper, a “point load method”, which firstlyseparates small users from large customers and then respectively locates the small usersaccording to the villages and given positions, is used for the rural load distributionforecasting.In this paper, a practical thinking line is proposed for medium voltage distributionnetwork planning. With the distribution transform locations being unknown in target years (such as in5year),10kV feeder routing are studied. Firstly, load partition basednetwork formation principle, i.e., Chain of Area Blocks is proposed. Then a DecreasingRedundant Mesh approach is employed to perform the load partition. Lastly,Minimum-cost Spanning Tree (MST) algorithm is employed to connect power supplypoints and virtual load points (load partition locations), and it provides favorablesituations for manual intervention of feeders’ routing along city streets. Theapplicability of the proposed method is demonstrated by using study cases.