基于变分模态分解的混合储能系统协调控制

针对自然条件下光伏电源出力的波动性和间歇性，以铅酸蓄电池和超级电容器组成的混合储能系统为基础，提出了一种基于变分模态分解（variational mode decomposition， VMD）的储能系统功率分层分配方法。储能系统承担的净负荷经过VMD分解后的高频波动分量分配给超级电容器承担，趋势分量分配给蓄电池承担；同时根据各储能单元的实时最大可充放功率和荷电状态对初级功率分配进行二次修正。仿真实例表明，该方法可有效平抑净负荷波动，并实现了储能系统调节特性的优化和储能单元的长期稳定运行。

Coordinated Control of Hybrid Energy Storage System Based on Variational Mode Decomposition

In view of the active power fluctuation and intermittence of photovoltaic (PV) power systems, based on a hybrid energy storage system consisting of super capacitors and lead-acid batteries, a layered active power allocation strategy is formulated to optimize the output power of PV source based on the method of variational mode decomposition (VMD). First, the net load which is supplied by the hybrid energy storage system is decomposed by VMD method. Then the low-frequency components and high-frequency components are allocated to the lead-acid batteries and super capacitors respectively to smooth out the fluctuations of output power of PV. At the same time, the orders of VMD filter are adjusted secondarily according to the state of charge (SOC) and the largest chargable/dischargable power in real time. The simulation tests demonstrate that using this method can effectively smooth out the fluctuation of net load, and the regulation performance and long-term and stable operation of the hybrid energy storage system are able to be optimized.