为了平滑光伏输出功率,提出一种基于模糊聚类经验模态分解(ensemble empirical mode decomposition,EEMD)的储能系统控制方法。通过对光伏信号的频谱分析,利用EEMD滤波分成高频和低频两部分,光伏低频分量作为光伏并网功率信号,高频信号接入储能系统吸收;使用储能电池荷电状态值、平滑波动率值状态作为约束条件,利用模糊控制算法,自适应在线调整EEMD滤波阶数,通过模糊自适应控控制器,实现了更好平滑光伏波动。对比定阶EEMD光伏功率储能控制策略,仿真实例表明,该方法可以充分使用储能系统平抑光伏功率波动,稳定储能荷电状态。
In order to smooth the PV power fluctuations, we put forward a control method with battery energy storage system (BESS) based on fuzzy ensemble empirical mode decomposition (EEMD). With a comprehensive analysis of the amplitude-frequency characteristics, PV power signal is decomposed by EEMD into two parts, the low-frequency parts are defined as wind power grid-connected value and the high-frequency parts are stored by BESS.Based on fuzzy control method, the orders of EEMD filter can be adaptively adjusted according to the state of charge (SOC) and fluctuation rate of PV power fluctuations after smoothing. Compared with the method with constant order of EEMD filter, simulation results show that the proposed method can effectively smooth the fluctuations of PV power output effectively by taking full advantages of BESS so as to keep SOC stable.