Research On Optimization And Planning Of Distribution Network Based On Totally Power Supply Capability

Distribution network is an important part of the power system,it is also an important foundation for the construction of a modern city.The traditional distribution network planning takes the load ratio as the design criterion.In order to ensure the reliability and safety of the power grid,the load ratio is usually designed largely.After years of large-scale construction,many of the city's distribution network has been rapid development,so the distribution network's equipment generally have a higher degree of safety.However,due to the uneven distribution of the load,the part of lines and equipments in the distribution network is born too much load and the time of heavy load running will be too long.Secondly,the urban land is increasingly tense,the cost of the substation and feeder is higher,so the difficulty of obtaining new planning land is becoming more and more difficult.At the same time,with the promotion of electric vehicles and other uncertain load and power market,the impact on distribution network is also increasing.The traditional planning method is hard to adapt to the needs of current planning.In the background of strong smart grid,the automation level and monitoring means of distribution network have been greatly developed.Through the reasonable planning,can make the distribution network has great potential to run at a higher margin of power supply.In the distribution network's planning and optimization,should fully consider the distribution network communication and distribution automation brought about the improving of power supply capacity and reliability,through the reasonable planning and optimization,distribution network load distribution and contact is became more scientific and reasonable,could improve the reliability of distribution network power supply and operation margin.In this context,the optimization and planning method of distribution network based on the totally power supply capability is proposed,and the related research is carried out.This paper first introduces the research status of distribution network optimization planning and totally power supply capacity at home and abroad.According to the actual distribution network topology structure and load distribution,the method of calculating the totally power supply capacity is determined.The method which calculates the power flow repeatedly.Then,based on the calculation of the totally power supply capability,several methods of distribution network optimization are presented,and integrating these means into the coding rules of optimization algorithm.Then,the optimization and planning model of distribution network based on the totally power supply capacity is build,use the fast non dominated sorting genetic algorithm to solve the model.Through cutting and changing lines,optimizing the contact switches' position to fully improve the power supply margin and reliability of the original distribution network.Finally,the distribution network's double layer expansion optimization and planning model based on the totally power supply capability is established.The model is divided into two levels,which separately plan the network and optimize the overall distribution network.The objective function of the second level is embodied in the first level's,making the connection between the two tier models closer and complementary.In this paper,the fast non dominated sorting genetic algorithm is applied to solve the two level model.Combined with the optimization means,the power supply margin and reliability of the new power supply area and the original distribution network are fully improved.The above work is verified by a simulation example,and the feasibility of the proposed method is proved preliminarily.This method is applied to optimize the distribution network of a district in the central city of Liupanshui,and achieved good results.