基于提升华北电网考核指标的飞轮储能参与调频划分电量控制策略

Flywheel energy storage participates in frequency modulation power division control based on improving power grid assessment index of north China power grid

在“双碳”目标的背景下,以风光为主体的具有明显随机性和波动性的新能源大规模并网,接入电网后容易造成电网频率波动,严重威胁电网安全。储能技术辅助调频主力的火电机组参与发电侧一次调频可以有效提升电网安全性和机组运行经济性。为充分利用飞轮储能辅助电网调频的优势,考虑储能当前电量对调频影响,建立火-储联合模型,分析火电-飞轮联合系统调频能力。本工作针对电网频率特性及机组调频特点,以满足调频指标为要求,充分考虑储能当前电量对调频性能的影响,提出一种基于提升华北电网考核指标的飞轮储能参与调频划分电量下垂控制策略。该策略根据飞轮储能当前电量进行计算,在不同电量时采用不同出力时间限制,以尽力满足电网一次调频考核指标。同时,利用MATLAB/Simulink软件分析了在负荷扰动下系统的调频效果及调频资源的出力情况。结果表明所提方法能够在飞轮储能电量处在不同状况时,利用不同放电时间来有效改善机组调频性能,提高机组量化指标。

Given the estimations that carbon emissions will peak by 2030 and carbon neutrality will be achieved by 2060 in China,large-scale new energy sources,with wind and solar as the main force,are connected to the grid.The increase in energy consumption leads to serious environmental problems.This may be resolved by using new energy,and accordingly,the structure of power generation has undergone significant changes.The largescale grid-connected new energy is associated with randomness and volatility.In addition,grid frequency fluctuation can be easily caused after penetrating the power grid, and this seriouslythreatens the safety of the grid. This issue can be resolved by improving the frequencymodulation supported by the power generation side. An energy storage system integrated withthermal power units participates in the primary frequency modulation, resulting in improvedsecurity of power grids and improved economic efficiency. To realize the advantages offlywheel energy storage auxiliary frequency modulation of the power grid, the frequencymodulation capability of the combined thermal power-flywheel system was analyzed based onthe model, considering the influence of current energy storage on frequency modulation. Inthis regard, this paper proposes a control strategy for flywheel energy storage participating infrequency modulation division based on improving the power grid assessment index of thenorth China power grid. The strategy is calculated according to the current electric quantity offlywheel energy storage, and different output time limits are adopted in different electricquantities to meet the primary frequency regulation assessment index of the power grid. Thefrequency modulation effect of the system and the output of frequency modulation resourcesunder load disturbance are analyzed using MATLAB/Simulink software. The results show thatthe proposed method can effectively improve the frequency modulation performance of theunit and improve the quantitative index of the unit with different discharge times underdifferent conditions of the flywheel energy storage. Thus, the proposed method provides goodsupport to the frequency modulation index at different power levels and effectively improvesthe economic assessment and efficiency of a power plant.