基于变分模态分解下利用混合储能平抑风电出力波动的控制策略

Control strategy of hybrid energy storage for suppressing fluctuation ofwind power output based on variational mode decomposition

针对风电有功功率波动这一问题,提出一种自适应滑动平均和变分模态分解相结合的滤波方法。针对某典型风电场出力数据,利用自适应算术平均法确定并网功率和储能系统充放电功率;采用变分模态分解方法把储能功率分解成一系列频率由低到高的子模态,从而完成混合储能系统功率的初级分配。针对功率型储能元件能量密度低,容易出现过充或过放的现象,对功率型储能元件的荷电状态进行实时监测。根据模糊控制制定的规则对混合储能系统的初级功率进行修正。算例分析表明,风电出力波动不但可以得到很好地平抑,而且混合储能系统也能够安全合理地工作。

In allusion to the active power fluctuation of wind power,a filtering mean combining adaptive moving average with variational mode decomposition is proposed in this paper.Firstly,according to output data typical wind farms,the adaptive moving average method is adopted to determine the grid-connected power of wind power and the charge-discharge power of hybrid energy storage system.The hybrid energy storage power is decomposed into a series of sub-modes from low frequency to high frequency by variational mode decomposition method to complete primary power distribution of hybrid energy storage system.Secondly,for the low density of power-type energy storage,the phenomenon of over-charge or over-discharge is likely to occur,and the SOC of the power-type energy storage element is monitored in real time.The primary power of hybrid energy storage system is modified by fuzzy control.The example analysis results show that the fluctuation of wind power output not only can be well stabilized,but also the hybrid energy storage system can work reasonably and safely.