平抑风电波动的混合储能系统控制方法

Control method of hybrid energy storage system to suppress wind power fluctuation

采用高功率密度的超级电容器和高能量密度的锂电池组成的混合储能系统平抑风电输出功率波动。通过滑动平均滤波获得并网功率与混合储能系统参考功率,采用离散傅里叶变换将混合储能系统参考功率分解,分别将高频信号和低频信号分配给超级电容器和锂电池。采用模糊控制方法对储能的荷电状态进行调节,实现功率的优化分配。仿真结果表明,所提出的控制策略能有效地平滑风力发电出力波动,同时保证储能设备的荷电状态维持在合理范围内。

A hybrid energy storage system consisting of a high-power-density super capacitor and a high-energy-density lithium battery were used to suppress wind power output power fluctuations.Firstly,discrete Fourier transform was used to decompose the HESS reference power which was derived by moving average and then the low and high frequency components were distributed to lithium battery and super capacitor,respectively.The state of charge control of hybrid energy storage system using fuzzy control method was applied to achieve optimal allocation and improve smoothing result.Simulation results show that the proposed control strategy can reasonably allocate power and effectively smooth the fluctuation of wind power output,while ensuring that the state of charge of energy storage equipment is maintained within a reasonable range.