面向风电波动平抑基于改进C−DCA的电池储能分组控制策略

Battery Energy Storage Grouping Control Strategy Based on Improved C−DCA for Wind Power Fluctuation Suppression

为解决电池储能系统(battery energy storage system,BESS)平抑风电波动过程中荷电状态(state of charge,SOC)和健康状态(state of health,SOH)一致性较低、电池寿命损耗较高的问题,该文提出了面向风电波动平抑基于考虑通讯时延的分布一致性算法(distributed consistency algorithm considering communication delay,C−DCA)的BESS分组控制策略,该控制策略包括初级和次级2个功率分配过程。首先,利用改进旋转门(improved swing door trending,ISDT)算法获取BESS功率指令;然后,建立考虑BESS寿命损耗、SOC与SOH一致性、并网波动率与算法迭代速度的双电池组初级功率分配模型,结合BESS充/放电状态将功率指令顺序分配至电池组,实现初级功率分配;接着,将状态反馈预测控制(state feedback predictive control,SFPC)与输出变量动态反馈引入C−DCA,形成改进C−DCA,进一步设计基于SOC−SOH的权矩阵计算方法,并根据改进C−DCA的计算结果将功率指令从电池组分配给电池单元,完成次级功率分配;最后,电池单元响应各自功率指令。以某风电场实际出力进行仿真,并与其它多种方法进行对比。结果表明,该研究方法降低了风电并网波动率,提升了控制算法的鲁棒性,减少了算法占用内存,同时兼顾了电池单元SOC和SOH的一致性,更大程度上降低了BESS寿命损耗。

To address the issues of low consistency between state of charge(SOC)and state of health(SOH)and high battery life loss during the suppression of wind power fluctuations in the battery energy storage system(BESS),this paper proposes a BESS group control strategy based on the distributed consistency algorithm considering communication delay(C−DCA)for wind power fluctuation suppression.This control strategy includes two power allocation processes,namely,primary and secondary power allocation processes.Firstly,the improved swing door trending(ISDT)algorithm is used to obtain the BESS power command.Then,a dual battery pack primary power allocation model is established that considers BESS lifetime loss,SOC and SOH consistency,grid connection fluctuation rate,and algorithm iteration speed.Combined with BESS charging/discharging status,power instructions are sequentially allocated to the battery pack to achieve primary power allocation.Next,state feedback predictive control(SFPC)and output variable dynamic feedback are introduced into C−DCA to form an improved C−DCA.A weight matrix calculation method based on SOC−SOH is further designed,and power instructions are allocated from the battery pack to the battery cells according to the calculation results of the improved C−DCA,completing secondary power allocation.Finally,the battery cells respond to their respective power commands.The results of simulating the actual output of a wind farm and comparing it with various other methods show that this research method can be adopted to decrease the fluctuation rate of wind power connected into the grid,improve the robustness of the control algorithm,and reduce the memory occupation of the algorithm;meanwhile,the method compromises the consistency of battery cell SOC and SOH,thereby greatly reducing BESS life loss.