混合储能系统平滑风电出力的变分模态分解-模糊控制策略

Variational mode decomposition and fuzzy control strategy of hybrid energy storage for smoothing wind power outputs

在风电机组并网处安装储能装置可以有效平滑功率波动,提出了变分模态分解-模糊控制策略平抑风电功率波动。首先通过滑动平均滤波获得储能系统参考功率,采用变分模态分解(Variational Mode Decomposition, VMD)将储能系统参考功率分解后,分别将高频信号和低频信号分配给超级电容器和锂电池。结合超级电容器和锂电池当前荷电状态与其参考值偏差,经模糊控制规则修正储能系统设备的充放电功率。最后利用Matlab/Simulink仿真,结果表明该控制策略不仅能够满足风电场最大输出功率变化率限制要求,还可以保持荷电状态(SOC)维持在合理范围,避免过充和过放的发生。

Equipping suitable energy storage devices in wind farm can smooth the output power fluctuation. A novel control strategy based on the variational mode decomposition and fuzzy controller is put forward in this paper. First, VMD is used to decompose the HESS reference power which is derived by moving average and then the high and low frequency components are distributed to super capacitor and lithium battery, respectively. Taking deviation between the current State Of Charge (SOC) of capacitor/ lithium battery and its reference value as constraints, the power of hybrid energy storage devices could be adaptively adjusted by fuzzy control method. Finally, the results of simulation from Matlab/Simulink show that the control strategy in this paper not only can meet the maximum output rate requirement of wind farms but also can remain the SOC in a reasonable range, which could avoid occurrence of over charge or over discharge of energy storage system.