基于离散傅里叶变换的主动配电网混合储能容量优化配置

考虑能量型储能和功率型储能的互补性，以混合储能系统（hybrid energy storage system，HESS）的投资运行成本及电能交易成本之和最小为目标函数，提出一种基于离散傅里叶变换（discrete Fourier transform，DFT）的主动配电网（active distribution network，ADN）混合储能容量优化配置模型。该模型采用离散傅里叶变换将混合储能系统功率分解成低频分量和高频分量，分别由能量型储能和功率型储能承担，优化分配混合储能系统功率。计及充放电状态对能量型储能寿命损耗的影响，计算能量型储能的充放电深度和寿命损耗，测算其使用寿命，进而计算投资运行成本。同时，考虑市场环境中的分时电价和电能交易，优化混合储能系统充放电功率，减少能量型储能寿命损耗。以改进IEEE 14节点配电网为例，利用我国华南地区某电网夏季典型日运行数据验证所提出模型的合理性和有效性。

Optimal Capacity Planning of Hybrid Energy Storage System in Active Distribution Network on the Basis of Discrete Fourier Transform

Taking into account the complementary of energy-type and power-type, this paper proposes an optimal capacity planning model of hybrid energy storage system （HESS） in active distribution network （ADN）based on discrete Fourier transform （DFT） to minimize the investment-operation cost of HESS. DFT is used to decompose the power of HESS into low-frequency component and high-frequency component. Low-frequency component is undertaken by energy-type energy storage system （EESS） and high frequency component is undertaken by power-type ESS （PESS）. Considering the influence of charge and discharge state on the lifetime of EESS, the depth of charge and discharge of EESS is calculated as well as the loss of lifetime of EESS. Actual lifetime of EESS is calculated and represent by investment-operation cost. In addition, taking into consideration the time-of-use electricity price and the difference of transaction power price, the optimal charge and discharge power of HESS and the reduction of lifetime loss of EESS are achieved. Case study is performed by use of modified IEEE 14-node distribution network and typical summer daily operation data. The results demonstrate the proposed model is correct and effective.