Active Distribution Network Planning With High Proportation Of Renewable Energy Generation

With the increasing capacity of distributed generation(DG)?the rapid popularization of electric vehicles and the continuous increase of controllable loads in modern distribution networks,the existing distribution network architecture and traditional planning methods are already changed.It is difficult to meet the requirements of power consumers in terms of power reliability,power quality and good service under the new situation.The impact of high penetration of renewable energy,such as the increase of nodal voltage level,bidirectional current,increase of short-circuit current,three-phase imbalance,harmonic pollution,etc,limit the large-scale integration of DG.This paper focus on the active distribution network(ADN)planning problem under the high proportion of renewable energy.Firstly,based on the existing literature in recent years,this paper reviews the DG planning methods for the ADN.Various planning models,active management measures,the treatment of uncertainty,characteristic of three-phase imbalance,and the coordination planning of the distribution network are analyzed and summarized,respectively.The ADN planning problem contains complex power flow equations and a large number of integer variables,thus it's a large-scale mixed integer.nonlinear programming(MILP)problem.This paper focuses on the analysis of ADN planning model and the coreresponding solving algorithm.Subsequently,this paper proposes a DG planning model and a fast solving strategy which consider multiple active management measures in ADN.Based on the conventional active management measures,the model also considers the effect of the distributed energy storage system.At the same time,the model also focuses on the analysis of line loss during DG planning,and the proposed model is transformed into the MILP model based on the DistFlow power equation model and various linearization techniques.Therefore,the model can be solved by state-of-art commercial solvers such as CPLEX..The method can determine the optimal location and capacity of DGs,which will improve the economic efficiency of distribution network planning.Secondly,this paper proposes a collaborative planning method for ADN which considers the allocation of DGs,ESS and network simultaneously.The objective isto minimize the investment cost of DG,network,energy storage,grid operation cost,energy storage cost and network loss cost.The constraints include capacity constraints,line selection constraint,power flow constraints,multiple active management constraints,etc.The proposed collaborative planning model is transformed into a MILP problem to achieve a good computation efficiency.The method can improve the planning and operation economy of the distribution system.Finally,this paper proposes a DG planning method which considers three-phase imbalance and multiple active management measures for ADN.The objective function is to minimize the annual comprehensive cost with respect to three-phase power flow constraints,DG construction constraint,various active management constraints,and three-phase voltage imbalance constraint.Based on the three-phase linear power flow,the DG planning model is transformed into a MILP problem.The proposed method is verified on the IEEE 34-node three-phase distribution system.