DG Sizing And Location Optimization Under Distribution Network And Probabilistic Load Flow

The use of distributed resources(DRs)or distributed generations(DGs)near to the consumption centers instead of the traditional large centralized power plants provides many advantages such as decreasing the investment of high voltage transmission lines as well as reduction of the power losses in transmission networks,and improvement of the reliability of the power supply.Because most of DGs are renewable energy,so it also provides less environmental impact.If the DRs or DGs resources are available in some region,DG sizing and DG location will seriously affect the operation of planned DG integrated distribution network,e.g.,the voltage profiles of distribution network will change even gets increased too much to harm the normal operation,large DG active power inserting into a not proper node of distribution network might bring a large current which may be high than the maximum value of conductor and causing over current of distribution lines;To avoid above negative impacts with alternative decreasing the rated output of DG might bring another negative impact of less utilization of distribution resources,which is not a good decision making.Therefore,DG sizing and DG location is a very important systematic optimization problem.In order to take full advantage of distributed energy,to make distributed energy mutual harmony between the existing distribution network and realize the power distribution system of economic,security,stability,and reliable operation,it is necessary to DG access the location and capacity of rational planning.The objective function of this paper is to minimize the sum of investment and operation cost,line loss cost and all purchase cost after DG access.Here penalty factor is introduced to restrict the operation of node voltage,conductor current and distributed generation.Inequality constraints are converted into equality constraints and are added to the calculation of objective functions.In order to grasp the external disturbance on the system operating conditions,the need to keep the monitoring system running,this time need a lot of power flow calculation.For the above problems,in this paper Probabilistic Power Flow Calculation based on Two-Point Estimate method chosen for load flow calculation and Genetic Algorithm used for finding Location and Size of DG in distribution network.Using MATLAB software programming and the actual power load based on historical data for the optimal solution.