基于共享储能容量分配机制的配电网双层优化策略

The two-layer optimization strategy of distribution network based on the capacity allocation mechanism of shared energy storage

【目的】高比例新能源接入带来的随机波动性使得配电网运行面临严峻挑战。为优化内部含多微电网与共享储能功率交互的配电网运行,提出基于共享储能容量分配机制的配电网双层优化模型。【方法】根据多微电网缺额负荷的差异互补特性,利用余弦相似度算法计算缺额负荷的相似度权重,结合缺额负荷对共享储能容量进行权重分配。建立了配电网潮流最优和电压偏移最小和多微电网弃风弃光最小和运行成本最小的双层优化模型。上层基于分配的储能容量优化各微电网出力范围,在配电网层求解中以得到微电网最优出力可行解并传递给下层;下层基于分配的储能容量进行多微电网共享储能的功率交互,实现多微电网的经济运行。【结果】利用改进的IEEE33节点系统对模型进行验证,结果显示:(1)共享储能容量分配机制与传统分配机制相比,配电网线损和电压偏移分别减小了9.8%和9.2%,多微电网的弃风弃光率和运行总成本分别降低了23.8%和6.1%;(2)对共享储能容量分配机制下的不同储能模式进行对比,共享储能比独立储能在多微电网的弃风弃光率和运行总成本方面分别降低了14.8%和3.3%。【结论】结果表明:合理有效的共享储能分配机制,可以促进高比例新能源消纳,提高共享储能整体利用率,实现配电网整体优化运行。

[Objective]The random fluctuation caused by the high proportion of new energy access makes the operation of the distribution network face severe challenges.In order to optimize the operation of the distribution network with the interaction between the internal multi-microgrid and the shared energy storage,a two-layer optimization model of the distribution network based on the shared energy storage capacity allocation mechanism is proposed.[Methods]According to the differential complementarity characteristics of the deficit load of multiple microgrids,the cosine similarity algorithm is used to calculate the similarity weight of the deficit load,and the weight allocation of the shared energy storage capacity is carried out in combination with the deficit load.A two-layer optimization model of optimal power flow and voltage offset in distribution network and minimal wind and photovoltaic abandonment,minimum operating cost in multi-microgrid is established.The upper layer optimizes the output range of each microgrid based on the allocated energy storage capacity,and obtains the feasible solution of the optimal output of the microgrid in the solution of the distribution network layer and transmits it to the lower layer.The lower layer carries out the power interaction of multi-microgrid shared energy storage based on the allocated energy storage capacity to realize the economic operation of multi-microgrid.[Results]The improved IEEE33 node system was used to verify the model,and the result showed that:(1)Compared with the traditional allocation mechanism,the line loss and voltage offset of the distribution network were reduced by 9.8%and 9.2%,respectively,and the curtailment rate and total operating cost of multi-microgrid were reduced by 23.8%and 6.1%,respectively.(2)Under the shared energy storage capacity allocation mechanism,compared with independent energy storage,the shared energy storage reduces the curtailment rate and total operating cost of multi-microgrid by 14.8%and 3.3%,respectively.[Conclusion]The result show that a reasonable and effective shared energy storage allocation mechanism can promote a high proportion of new energy consumption,improve the overall utilization rate of shared energy storage,and realize the overall optimal operation of the distribution network.