风电波动平抑下考虑SOC均衡及收益的电池储能功率分配策略

Power Allocation Strategy Considering SOC Balance and Income for Battery Energy Storage in Smoothing Wind Power Fluctuations

针对电池储能(battery energy storage system,BESS)平抑风电波动过程中电池单元荷电状态(state of charge,SOC)均衡性较差且未考虑风储净收益的问题,提出了风电波动平抑下考虑SOC均衡及收益的BESS功率分配策略。首先,建立综合考虑售电收益、弃风惩罚、缺电惩罚及BESS运行成本等多个因素的风电并网指令优化模型,以并网指令波动率、电池组SOC标准差等多个因素为约束条件,提出改进算术优化算法(improved arithmetic optimization algorithm,IAOA)求解该优化模型。然后,将BESS划分为两个电池组,设计了BESS双层功率分配方法(double-layer power allocation method,DPAM),上层将BESS充放电指令分配给两个电池组,下层根据最大充放电功率原则或新型SOC均衡原则将电池组充放电指令分配给各自的电池单元。最后,通过仿真对所提策略进行了验证。仿真结果表明:IAOA加快了寻优速度,提高了寻优精度;DPAM提升了电池组内电池单元SOC的均衡速度,改善了均衡程度;提出的功率分配策略进一步降低了风电并网波动率,同时提高了风储系统净收益。

Aiming at the state of charge(SOC)imbalance of battery units and neglecting the wind-storage net income in the process of smoothing wind power fluctuations by battery energy storage system(BESS),we proposed a power allocation strategy for BESS where the SOC balance and the income are taken into account.Firstly,an optimization model for grid-connected wind power signal was established comprehensively by taking into account multiple factors of the electricity sale revenue,wind curtailment penalty,electricity shortage penalty,and operation cost of BESS.Meanwhile,multiple factors of grid-connected power signal volatility,standard deviation of SOC for battery groups,and so on,were selected as the constraints.An improved arithmetic optimization algorithm(IAOA)was proposed to solve the optimization model.Then,the BESS was divided into two battery groups,and a double-layer power allocation method(DPAM)for BESS was designed.The upper layer assigns the charging/discharging power signal of BESS to the two battery groups,and the lower layer allocates the charging/discharging power signal of each battery group into its battery units with the power allocation principle of maximum charging/discharging power or novel SOC balance.Finally,the proposed strategy was verified by simulation.The results show that IAOA speeds up the optimization speed and improves the optimization accuracy.DPAM enhances the speed of SOC balance for battery units in battery groups and improves their balance degree.The proposed power allocation method can be adopted to further reduce the volatility of grid-connected wind power and improve the net income of wind-storage system.