Distributed Generation Sources Planning In Active Distribution Networks Considering Cooperation Of Energy Storages

Active distribution network(ADN)is a distribution network with ability of controlling various kind of distributed generation sources,whose purpose is to increase the capacity of distribution network for renewable energy,improve the utilization of distribution network assets,postpone investment in distribution network,and improve power quality and power supply reliability of the system.With the integration of large-scale distributed generation sources,the power loss,voltage and investment benefit index of distribution network play a more important role in the optimizing allocation process.However,the intermittent distributed generation sources have the characteristic of uncertainty,which increases the fluctuation of the distribution network and brings new problems to the related planning work.As an important part of the active control for ADN,energy storage devices balance the stochastic fluctuation brought by distributed generation sources to a certain extent.Therefore,the study on distributed generation sources planning in ADN considering energy storage is of great practical significance.Firstly,the output characteristics of wind power and photovoltaic power generation are modeled,and the probability density distribution of them is obtained.According to sequence operation theory,the discrete probabilistic sequence of wind power generation and photovoltaic power generation is generated by the probability density distribution,and the expected values of wind power generation and photovoltaic power generation are obtained,which lays the foundation for dealing with the uncertainty of distributed generation sources.The influence of distributed generation sources connected to ADN is analyzed,which is instructive to the establishment of objective functions of the post programming model.Secondly,a two stage model of distributed generation sources planning in active distribution networks is proposed.The model uses the multi-objective function of the maximum investment benefit of distributed generation sources,the minimum power loss of the system and the maximum voltage stability factor,and uses the multi-objective ant lion algorithm to optimize the configuration of the distributed generation sources,and then the ‘best' compromise solution is identified by calculating the priority memberships of each solution via grey relation projection method,while finally,in order to address the uncertain outputs of distributed generation sources,energy storage devices are installed whose maximum outputs are determined with the use of chance-constrained programming.Finally,the planning of distributed generation sources in the ADN and the daily operation of energy storage are combined.The optimal dispatch of energy storage devices in ADN is taken into account,so that the daily scheduling of the energy storage devices can reduce the planning error brought by the uncertainty of the distributed generation sources,which makes the planning more effective and practical than the traditional planning.The test results on the PG&E69-bus distribution system validate the effectiveness of the proposed approach.