基于离散傅里叶变换的孤岛型微电网混合储能优化配置

分析了孤岛型微电网中电源负荷不平衡功率的产生,基于离散傅里叶变换,将不平衡功率分解成日分量和小时分量,分别采用压缩空气储能和钠硫电池平衡该分量,为了使得分解后的日分量和小时分量最优,专门研究了不平衡功率离散傅里叶变换分断点的分断原则。在此基础上,综合计入储能投资运行成本、系统缺电损失费用和弃风惩罚费用等,建立孤岛型微电网混合储能优化配置模型。该模型可以实现离散傅里叶变换分断点和混合储能容量的统一优化,且优化过程中实现了压缩空气储能和钠硫电池两种储能容量优化配置的完全分解,简化了模型的求解复杂性。采用实际微电网系统进行了算例分析,验证了所述模型和方法的正确性。

Capacity Optimization of Hybrid Energy Storage Systems in Isolated Microgrids Based on Discrete Fourier Transform

Firstly, imbalance power in isolated microgrids has been analyzed. Based on discrete Fourier transform(DFT), the imbalance power is decoupled into day and hour components, which can be balanced by compressed-air energy storage and sodium-sulfur cell, respectively. In order to obtain the optimal components, the DFT segmentation principle is studied. By considering investment and operating cost including energy storage, loss of load and wind abandoning penalty comprehensively, the capacity optimization model of hybrid storage systems for isolated microgrids is built. This model can simultaneously optimize the DFT segment point and the hybrid energy storage capacity. And its solving complexity has been greatly simplified as the model can thoroughly decouple the configuration optimization of compressed-air energy storage and sodium-sulfur cell. Finally, the correctness of the model and the method has been verified in a certain practical microgrid. This work is supported by National Natural Science Foundation of China(No. 51307185), Fundamental Research Funds for the Central Universities(No. CDJPY12150002)and China Southern Power Grid Company Limited(No. K-GZ2013-468).