Research On Optimal Allocation Of Energy Storage In Distribution Network

In recent years,the rapid development of new energy sources and the gradual popularization of electric vehicles have led to new challenges in the power system at both ends of the "source-load" spectrum.In order to cope with these changes,adding Energy Storage System(ESS),which has the ability to reduce peaks and fill valleys,smooth fluctuations and regulate flexibly,is one of the effective solutions.However,the cost of ESS is still relatively high,so it is necessary to optimize the configuration of ESS in terms of its economy and application scale.This paper focuses on the optimal configuration of ESS in distribution networks with high penetration of intermittent new energy sources,including the optimization of access location and capacity.Referring to the site selection method based on the traditional voltage-active power sensitivity calculation,the actual situation of each node is considered,and the node with high sensitivity and no deterioration of the characteristics of the remaining nodes is selected as the node to be connected to the energy storage system.Then,the influence of two types of factors,namely timing and network operation mode,is considered in the sensitivity calculation,and finally three improved voltage-active power sensitivity calculation methods are obtained in layers to obtain the nodes to be selected for access to the energy storage system.Combining the structure and tidal distribution characteristics of the distribution network,a multi-point siting method of the energy storage system is proposed,which effectively reduces the search range of the nodes to be selected and reduces the workload of energy storage siting,while making the distribution of the energy storage system more reasonable.According to the partitioning principle of multi-point siting,the obtained regions are equated to obtain a new simplified network topology and related parameters,and then an improved voltage-active sensitivity analysis is performed on the simplified network.Considering the priority of regional configuration and the impact of energy storage access,the region corresponding to the node with the highest sensitivity is selected for constrained energy storage capacity configuration.Then,the region corresponding to the node with the second highest sensitivity is configured for capacity,and other regions are sequentially configured.Based on this,a capacity configuration scheme that meets the operational requirements of the distribution network and achieves the optimal results in various regions can be obtained.The optimal configuration method of energy storage system proposed in this paper can give a simple,fast and accurate configuration scheme,and it does not need to recalculate after the improvement target is changed,but only needs to re-match the areas where energy storage is added according to the new improvement target,which is providing a reference for the optimal configuration scheme of energy storage that requires multi-point site selection.