基于经验模态分解的混合储能系统功率分配方法

POWER ALLOCATION METHOD OF HYBRID ENERGY STORAGE SYSTEM BASED ON EMPIRICAL MODE DECOMPOSITION

为了降低储能系统充放电次数,提高储能系统的使用寿命,提出一种基于经验模态分解(empirical mode decomposition,EMD)的混合储能系统功率分配方法。风电输出功率经过EMD滤波后的低频分量作为风电并网功率信号,中频和高频分量分别由储能电池和超级电容器吸收;同时根据混合储能系统的荷电状态,自适应调整EMD的滤波阶数以维持荷电状态的稳定。仿真实例表明,该方法可有效平抑风电功率波动,避免储能介质的过充过放,达到延长电池使用寿命的目的。

In order to reduce the charging and discharging times and prolong the life of energy storage system, a power allocation method of hybrid energy storage system based on empirical mode decomposition （ EMD ） was proposed. After wind power was decomposed by EMD, the low-frequency component was available as wind power grid-connected value, and the intermediate frequency and high frequency components were absorbed by the storage batteries and super-capacitors to smooth the fluctuations of output power of wind turbine. At the same time, the orders of EMD filter were adaptively adjusted according to the state of charge （ SOC ） of hybrid energy storage system to maintain the stability of the SOC. The simulation tests showed that the method can effectively smooth the fluctuations of output power and avoid the over-charging and over-discharging of energy storage system to prolong the life of energy storage system.