Research On Multi-Objective Planning And Dispatching Of Distributed Energy Storage In Distribution Network With Renewable Energy

In the background of "carbon peak,carbon neutral" target,the proportion of renewable energy in China’s energy structure is increasing year by year,and the distributed generation(DG),mainly wind power and photovoltaic power generation,is connected to the distribution network,which makes the operation of the power system more complicated due to its intermittent and fluctuating nature.At the same time,due to the rapid development of the economy,the electricity consumption of users gradually increases,making the peak-to-valley difference of the load bigger.Distributed Energy Storage(DES)has a very important application value in suppressing the fluctuation of renewable energy generation,improving voltage quality,and reducing the peak-tovalley difference of load,etc.Its scientific planning and scheduling are of great practical significance to ensure the safe,stable and economic operation of distribution system.This paper researches two applications of DES in distribution network planning and scheduling,which mainly include:1.For the DES planning problem in distribution networks containing renewable energy,a multi-objective planning method for DES based on node integrated sensitivity is proposed.Firstly,we analyze the rationality of DES access location from the perspectives of voltage improvement and active network loss reduction,propose the node comprehensive sensitivity index,and screen out the DES nodes to be installed;secondly,with the objective function of minimizing voltage fluctuation,active network loss and energy storage planning cost in the distribution network,we comprehensively consider the planning and operation of DES,establish a DES multi-objective planning mathematical model,and establish a DES multi-objective planning model based on Pareto theory.An improved multi-objective sparrow search algorithm with enhanced population diversity and convergence accuracy is designed to solve the proposed model;the simulation results show that compared with the DES planning method considering all installable nodes,the DES planning method based on the integrated sensitivity of nodes is not only more conducive to reducing voltage fluctuation and active network loss,but also more efficient in solving.At the same time,it is verified that the proposed improved algorithm has a stronger finding capability compared with other algorithms.2.To address the DES dispatching problem in distribution networks,a DES peakshaving and valley-shaving optimal dispatching method with demand response is proposed,and a two-stage peak-shaving and valley-shaving optimal dispatching model is designed.Firstly,the load demand response optimization model is established with the objective functions of minimizing the peak-to-valley load difference and maximizing customer satisfaction through the study of load demand and time-of-use tariff;then,based on the demand response optimization results,the DES peak-shaving optimization scheduling model is constructed with the objectives of minimizing the standard deviation of load and distribution network operation cost,which is transformed into a mixed integer second-order cone by using the second-order cone relaxation technique.The simulation example shows that the DES optimal dispatching method considering demand response can achieve better peak and valley reduction and lower distribution network operation cost,and the model based on second-order cone relaxation can significantly reduce the complexity and improve the solution efficiency while ensuring the global optimal solution.