Research On Distribution Network Planning And Optimization Proposal In Mountain Area With Small Hydropower

The vigorous exploitation of non-renewable energy sources and the increasing pollution of the environment have caused us to urgently seek suitable renewable clean energy sources to ease the current status quo.China's hydropower resources are rich in reserves,and the degree of exploitation and utilization has yet to be improved.Small hydropower,as a typical renewable clean energy source on the user side,has become an energy supply point for some rural and mountainous regions.However,due to the limitations of geographical location and natural environment,as well as its own seasonal fluctuations,it has caused a series of problems in its full use and planning.In response to the above issues,the work of this paper mainly includes:(1)Put forward the method of flooding the small-scale hydropower staggered peaks in the flood season and adjusting the voltage assessment scope of the substation bus,so as to ease the high voltage of the access point and the phenomenon of abandoning electricity.Among them,the voltage assessment range of the bus is adjusted by means of the fourquadrant scatter diagram of "consumption ratio and substation delivery ratio".(2)The power supply radius of 10 kV with high proportion of small hydropower mountainous areas was determined.From the demand side—the load of the connected line,the configuration of the transmission side—the line model,the access capacity of the SHP,and the power supply radius of its own layout,the main factors causing the voltage deviation are analyzed.Determine the reasonable 10 kV power supply radius reference value for mountainous areas with more small hydropower.It is recommended that the maximum power supply radius of 10 kV is 13 km for the line with small hydropower capacity of 2MW~3MW.In addition,it is suggested that the power supply radius can be increased to 15 km in areas with little or no small hydropower.If the wire section is large,the power supply radius can be extended to 20 km.To find the power supply radius of 10 kV medium voltage distribution in the mountainous area,and provide some suggestions for the reasonable planning of mountainous area.(3)Established a substation economic capacity optimization model that follows the best life cycle cost of assets.Based on the basic principle of optimization theory and economics,follow the principle of life-cycle cost optimal assets,considering the influence of the hierarchy and small hydropower network access,use run economic and technological parameters of the transformer and line construction,from grid computing annual total cost of substation economic capacity optimization model is established.According to the economic comparison,the construction cost of the planning model considering the small hydropower is less than the cost without consideration and has certain economic benefits.(4)Presented an evaluation system that is applicable to the three-level indicators applicable to the current distribution network.For the three levels of indicators,the corresponding index meanings and corresponding scoring methods are respectively given.The Delphi method and the AHP method are used to calculate the index weights for each level.And using this evaluation system to analyze the existing problems in the current distribution network of mountainous areas,and propose application proposals for the establishment of 35 kV simple substations in mountainous areas with high proportion of small hydropower to provide reference for the distribution network planning in mountain areas.This paper focuses on the planning and optimization recommendations for distribution networks in small mountainous areas containing small hydropower.According to the influence of SHP access,this paper determines the power supply radius of the 10 kV line in the mountainous area,and establishes a life-cycle economic capacity model containing small hydropower,providing reference for the selection of distribution capacity.This paper proposes the evaluation system of the current distribution network,and puts forward specific optimization suggestions for the distribution network of small-scale hydropower stations.