Study On DG Multi Scenario Bi-level Planning Considering Outage Loss Of Distribution Network

In recent years,fossil resources have been increasingly depleted,and the contradiction between the pollution problems caused by coal and other fossil resources for power generation and people’s needs for a green ecological environment has become increasingly prominent.Wind power is favored by power supply companies in various countries due to its renewability,flexible power supply mode,and low pollution.It has become an indispensable and beneficial supplement to power supply companies’ power supply.Wind power has also developed rapidly.However,because the output power of distributed generation(DG)is closely related to the wind speed,the wind speed is affected by geographic location and has great randomness,which makes DG output uncertain and large-scale output uncertainty.After the grid connection of the DG,it will affect the power quality,reliability and stability of the distribution network.In order to ensure the safety and stability of the system,the distribution network company has to increase planning investment,but the two parties have not coordinated the planning,resulting in investment Unreasonable and repeated construction have lowered the profitability of both parties,making it difficult for distribution network companies to actively absorb DG,and ultimately resulting in a serious shortage of DG construction power and capacity,which affects the sustainable development of distributed power generation.In order to promote the distribution network to absorb DG and increase the profitability of both parties,this paper proposes a DG two-level planning method that considers the loss of the distribution network in multiple scenarios,and realizes the mutual benefit and win-win situation of the distribution network company and the DG generator.The main research results obtained are as follows:(1)In view of the fact that there are few literatures in DG planning research that consider the benefits brought by DG to recover the power loss of the distribution network,a DG bi-level programming model that considers the cost of power loss is proposed.The upper-level model aims at maximizing the net income of the DG power generation company,uses the network loss sensitivity method to determine the candidate installation location of the DG,and optimizes the location and capacity of the DG;the lower-level model aims at maximizing the net income of the distribution network company.The islanding method dynamically optimizes the installation position of the segmented switch,and can provide power in an island in the event of a system failure,reducing the loss of the distribution network.At the same time,in order to reduce the loss of the distribution network and maintain voltage stability,the reactive power compensation device is optimized.The genetic algorithm is used to solve the above model,and the IEEE33 node calculation example is used for simulation verification.The results show that the model and method can reduce the loss of power outage in the distribution network while promoting DG consumption,and achieve a win-win situation for both parties.(2)In view of the uncertainty of DG output,a large number of wind speed scenarios are constructed using probability density function and roulette method,and K-means mean clustering is used to obtain expected scenarios and corresponding probabilities,and a DG output model under multiple scenarios is further constructed to solve the problem of DG output failure.The problem of certainty;then,a DG bi-level planning model considering the cost of power outages in the distribution network under multiple scenarios is constructed.The upper-level model uses the largest average annual net income of distributed power generators under multiple scenarios as the objective function to optimize the DG installation location and Capacity: The lower-level model takes the maximum average annual net income of the distribution network company in multiple scenarios as the objective function,and uses the islanding area division method to provide island power supply when the system fails to recover the power outage loss of the distribution network in multiple scenarios.The genetic algorithm is used to solve the constructed two-layer model,and the IEEE33 node calculation example is used to simulate and verify.The calculation example results show that the output of multi-scenarios in DG planning is much higher than that of only considering the typical sunrise power.DG consumes and improves the profitability of both parties.