风储联合发电系统电池荷电状态和功率偏差控制策略

SOC and Power Deviation Control Strategy for Hybrid Generation Systems of Wind Power and Energy Storage

提出了一种新型的基于风电功率预测偏差和电池荷电状态(SOC)反馈的储能系统控制策略,通过预测结果计算风电功率的变化偏差,得出完全补偿波动所需的储能系统充放电功率,引入补偿系数联合求解获得储能系统的充放电控制指令。同时,建立了补偿系数的动态优化模型,包括长时间尺度下基于输出功率波动和电池容量变化指标的基准补偿系数寻优模型,短时间尺度下基于电池SOC指标和充放电状态的补偿系数快速修正模型。算法采用的最优求解和SOC指标具有广泛的适应性,便于推广不同容量储能系统在风电功率平滑中的应用,可以兼顾储能电池的寿命和输出功率的平滑性。算例结合风电场的功率实测数据,进行储能系统配置仿真,验证了该控制策略能够最大程度发挥储能系统能力,在维持电池能量稳定前提下,平抑风电场输出功率的波动。

A new control strategy of energy storage systems ESSs based on wind power prediction deviation and battery state of charge SOC feedback is proposed.The deviation of wind power variation is calculated through prediction results to get the charge-discharge power of ESSs needed by totally compensating fluctuation.The charge-discharge power orders are then obtained by introducing the compensation factor in the joint solution. Moreover, a dynamic optimizing model of the compensation factor is developed, including the standard compensation factor optimizing model based on output power fluctuation and battery capacity changing value and the compensation factor fast-modification model based on battery SOC and charge-discharge status under short-time scale.The optimal solution and SOC value used in the proposed algorithm have a high adaptation level,which can generalize ESSs of different capacities in the application of wind power smoothing and give consideration to the lifetime of battery and smoothness of wind power.Finally,a case study is made that describes simulations with the historical power data on wind farm and ESSs configuration taken into account.The results have proved that the control strategy is able to develop the capacity of ESSs to the full and reduce the fluctuation of wind farm power on the premise that the energy capacity of battery is maintained stable.