面向风功率波动平抑的电池储能双层协调控制策略

Coordinated Two-layer Control Strategy of Battery Energy Storage for Wind Power Fluctuate Mitigation

为保证电池储能持续平抑波动,该文提出一种基于双层协调控制的电池集成储能控制策略。外层控制中,提出基于近零相位自适应滤波的风功率平滑策略,不仅使并网功率满足1、10 min时间尺度波动平抑需求,还减小了控制过程中相位滞后,并在风功率较平稳时自适应控制储能系统退出运行,有效降低了储能系统额定功率需求和运行负担。内层控制中,采用不同充、放电特性的两组磷酸铁锂电池集成以跟踪功率指令,并定义等效荷电状态(state of charge,SOC)指标衡量储能系统的整体SOC水平,随后将等效SOC与外层控制相联系,提出基于Logistic动态区间的SOC优化策略,确保优化过程中并网功率满足要求,并解决充、放电不均衡情况下的高/低SOC极端运行状态,保证电池储能持续平抑波动能力,同时可使两组电池储能接近最优放电深度(depth of discharge,DOD)运行,充分利用其循环寿命。

The coordinated two-layer control strategy of integrated battery energy storage for wind power fluctuation mitigation is proposed.In the outer control,the wind power smoothing strategy based on near-zero phase adaptive filtering is proposed.This strategy not only ensures that the grid-connected power aligns with the power fluctuations at 1-minute and 10-minute timescales but also minimizes the phase lag during the control process.When the wind power is relatively stable,the energy storage system can adaptive exit operation,effectively reducing the rated power requirement and operation burden of the energy storage system.In the inner control,the dual lithium iron bisphosphate batteries with different charging/discharging characteristics are used to track the power,and the equivalent SOC index is defined to measure the overall SOC of the energy storage system.Then,the equivalent SOC is linked to the outer control,and the Logistic dynamic interval strategy for SOC optimization is proposed.It ensures that the grid-connected power meet the requirements in the optimization process,solves the extreme operation state of high/low SOC when the charge and discharge energy is unbalanced,and enables the ability of battery energy storage to continuously mitigate power fluctuations.Meanwhile,the two groups of batteries can operate at the optimal depth of discharge,so as to make full use of the cycle life.