Research On Energy Storage Planning Of Distribution Network With High Proportion Of New Energy

In recent years,large-scale renewable energy generation equipment has replaced traditional units and integrated in the distribution network to comply with the development trend of clean energy.The limited hosting capacity of distribution network has become the main factor restricting the development of renewable energy.In this context,electric energy storage technology,due to its flexible power regulation characteristics,plays a key role in coping with a series of problems such as increased difficulty in peak regulation and reduced power quality caused by the high proportion of renewable energy integration.However,the high investment of energy storage limits its large-scale application in distribution network.How to plan energy storage reasonably in different scenarios is worthy of in-depth study.At the same time,as a new type of load,electric vehicles have become an important supplement to physical energy storage due to their mobile energy storage characteristics that do not require additional consideration of configuration and cost.Therefore,formulating an orderly charging and discharging strategy for large-scale electric vehicles is of great significance for improving the economics of energy storage planning.This thesis conducts research on energy storage planning issues of distribution network with renewable energy in different scenarios.The main research work and innovative achievements are as follows:(1)An energy storage power station planning method considering source-storage collaborative peak regulation is proposed for the high-voltage distribution network with new energy.Typical output scenarios of sola and wind power that conform to spatiotemporal correlation characteristics is generated by using R-vine Copula theory and Markov Chain Monte Carlo method.The energy storage power station planning model considering the technical and economic benefits of system peak regulation is established based on the evaluation of the adequacy for distribution network peak regulation.The simulation results of the case and the actual power grid show that the proposed planning method for energy storage power stations can effectively alleviate branch congestion,promote new energy consumption,reduce the peak regulation burden on the bulk grid,and leave sufficient peak regulation margin for the subsequent development of new energy distribution network while ensuring economic efficiency.(2)A distributed energy storage planning method for optimizing system operation is proposed for the medium-voltage distribution network with high permeability photovoltaic.A distributed energy storage bi-level planning model for optimal operation of distribution network is established considering the reactive power adjustment capability of distributed photovoltaic and energy storage.The outer level model for distributed energy storage siting and sizing is established considering the cost of energy storage configuration and the degree of indicators optimization.The inner level model for distributed photovoltaic and energy storage optimization operation is established considering voltage deviation,voltage fluctuation,network loss and distribution transformer load rate.The simulation results of the case and the actual power grid show that the proposed distributed energy storage planning method can effectively reduce the network loss,reduce distribution transformer reverse overload and voltage overlimit,and make the distribution network operate in the optimal state under a more economical planning scheme.(3)An optimization strategy for orderly charging and discharging of electric vehicles considering mobile energy storage characteristics is proposed for the load side.The dynamic clustering model and the cluster charging and discharging model for electric vehicles are established by analyzing the spatiotemporal characteristics of electric vehicle mobile energy storage.The cluster-based optimization strategy for electric vehicles charging and discharging with variable rolling horizon is proposed based on the mechanism of multi-party information interaction.The simulation results of the power grid case show that the proposed electric vehicles charging and discharging strategy can reduce the cluster charging cost,make full use of the energy storage characteristics of electric vehicles for peak load shifting and promote the consumption of photovoltaic power generation.The proposed method can also improve the economy of energy storage planning by reducing the installation cost of physical energy storage.