| Under the background of global "two-carbon",the development of wind energy,solar energy and a series of fluctuating energy sources has received unprecedented attention.On the one hand,the access to volatile energy alleviates the energy crisis and environmental pressure,but also brings new challenges to the reliability of the power system and the balance of power quantity.The combination of "volatile energy + energy storage" can well solve these problems.In view of the problems such as the increased difficulty of accessing volatile energy to the active distribution network,the increased voltage deviation of the grid and the decreased security and stability,etc.,therefore,It is of great significance to study the improvement of energy storage system in power quality and safe and stable operation of active distribution network with fluctuating energy.The main research work of this paper is as follows:Firstly,for the output characteristics and operation effect of two volatile energy sources,wind power and PV,as well as lead-acid battery and super-capacitor energy storage,the corresponding equivalent model is built to provide a basis for optimizing the energy storage configuration in ADN;and simulation tests are conducted to analyze the impact of different influencing factors on the output situation and operation effect,analyze the necessity of the characteristics of VG for energy storage configuration,and use the time-sharing tariff to divide the grid load demand to Determine the charging and discharging time period of the energy storage system to achieve the goal of reducing the comprehensive cost,peak and valley reduction,and establish a hybrid energy storage system planning model for energy storage system to complete the response to load demand,enhance the interaction between grid and load side,and realize the"source-grid-storage-load The integrated and collaborative operation of"source-grid-storage-load" is realized.Secondly,a two-layer optimal configuration model based on the impact of VG on the energy storage system is established.On the basis of the multi-objective optimization model,the upper layer uses the predicted values of wind,light and load days ago for the planning of the distribution grid and the hybrid energy storage system of lead-acid batteries and super-capacitors,and solves the initial value of the capacity configuration by using the improved multi-objective optimization particle swarm with the objective of optimal integrated cost,network loss and node voltage deviation;the lower layer solves the model with the optimal system frequency deviation index of wind power output to adjust the output of the energy storage system,and solves the The revised value of the configured capacity of super-capacitor and the quantum particle swarm with chaotic mechanism are introduced to further optimize the output of various units in the grid.The upper layer of energy storage coordinates the operational scheduling while planning,and further feeds back the planning through the operation of the lower layer involved in frequency regulation to form a dynamic optimal scheduling to achieve the optimal energy storage configuration.Finally,the IEEE33 node system is improved,and the simulation comparison is made through Matlab software in three different scenarios,and the actual power generation and load data of Jiuquan city are used for model verification.The overall operation results of the power grid are analyzed from the perspective of reducing the economic cost,suppressing the effect of energy fluctuation and optimizing the frequency fluctuation.In the final comparative analysis,the optimized frequency fluctuated within-0.024 Hz —0.016 Hz.The total cost of this study was saved by 44.72% and 37.13% compared with the other two scenarios,and the network loss was reduced by 0.53 MW,which verified the rationality and efficiency of the energy storage two-layer optimal configuration model and the corresponding solution algorithm proposed in this paper. |
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