Research On The Method Of Location And Capacity Determination Of Substations Considering Peak Shaving Energy Storage

As the permeability of new energy in the power network is increasing gradually,and the power load is increasing rapidly,higher requirements for the planning of the power network are put forward.Substation,as the base station to maintain electric power transportation,plays a vital role in the power grid.Therefore,the location,capacity and optimization planning of substations become the top priority in the whole process of distribution network.Due to the large upfront investment cost and its long period of substation,it is necessary to find a more comprehensive method to study the cost.At the same time,energy storage technology can effectively solve the problems such as the uncertainty of new energy and the large peak-valley difference of load existing in the current distribution network due to its features of flexible access location,strong absorption capacity and fast response rate.However,energy storage system has not been applied in a large scale due to cost factors.In this context,this dissertation takes the substation and energy storage as the research object.Starting from the practical problems of the power grid,based on the entire life cycle theory,this dissertation studies the collaborative optimization of the location and the energy storage capacity of the substations,so as to improve the economy and security of the power grid operation.This dissertation mainly carries out the following aspects of work:(1)In view of the optimal location of substation,a method of weight of factors for location of substation based on centroid theory is proposed.Firstly,the center of mass theory is studied to determine the load center of the planning area.Secondly,the factors of substation location were sorted out,and the dimensionless weights of each factor were obtained by using the interval number correlation degree method and the mean square deviation method.Then,through comprehensive calculation combined with the above two results,the final weights of substation site selection factors are obtained.Finally,the site evaluation index based on fuzzy evaluation theory is proposed to evaluate the selected site to obtain the optimal site.(2)Considering the collaborative optimization of substation and energy storage capacity,an optimization method of energy storage capacity based on improved genetic algorithm is proposed.Firstly,the output models of photovoltaic and wind power are studied and established.Then,considering the balance of power and quantity in the planned region,the net load curve is calculated by combining the new energy output and the regional load curve.Finally,considering the entire life cycle cost of the substation and energy storage equipment,time-sharing electricity price and the energy storage equipment is cutting peaks and filling valleys of the power load,this dissertation establishs a subatation-energy storage capacity collaborative optimization model with the maximum comprehensive benefit as the objective function.(3)The dissertation plan example of the “Three Rivers and Six Banks” Project in Lishui District,Nanjing.Firstly,the current status and the planning objectives of the power grid in the planned area are sorted out,including load,surrounding power supply and other elements.Then,based on the above research contents,a power supply planning scheme that considers the coordinated optimization of the substation and energy storage in this region is proposed.Finally,the superiority of the proposed planning scheme is demonstrated through the comparative analysis of the schemes.Traditional solutions include: 1.Power grid companies build new substations to increase capacity;the users only self-build substations;The scheme proposed in this dissertation is to build a comprehensive energy station(substation and energy storage)for users.The comparative analysis results show that the collaborative optimization of substation and energy storage capacity in this dissertation can effectively reduce the entire life cycle cost of substation construction and has the highest economic benefit.