储能系统辅助火电厂AGC调频的动态协同运行特性研究

With the demonstration using energy storage technology to assist thermal plant AGC frequency modulation(FM) have been carried out, improving the overall AGC FM ability of thermal power unit combined energy storage system to alleviate the burden of power grid has become the research hotspot. Thermal power units and energy storage system have different advantages in regulating speed, tracking ability and regulating capacity, but if those advantages mismatch with the characteristic of AGC condition, it will lead to the risk of weakening FM ability that caused by the improper use of swap frequency source or energy hedge in two kinds frequency modulation equipment. According to the problem above, the project study the external characteristic of energy storage system that is suitable for FM operating, found the quantitative relation between power and capacity of energy storage with those of thermal power unit’s which has the same AGC FM capacity, for fully grasping the regulation performance of different FM resources; By constructing differential games and dynamic coordinated control model of energy storage system and thermal power unit’s state space coupling systems, analyzing the complementary and hedging characteristics of thermal power unit combined with energy storage system, dynamic collaborative operation characteristics and its criteria, and the multi index optimization and collaborative operation control algorithm, in order to implement the optimize and coordinated operation of thermal power units and energy storage system, and then achieve to promote the overall FM ability, provide important technical thought to promote different FM resource’s mining use and improve the overall frequency control ability of electric power system.

随着储能技术辅助火电厂AGC调频示范的开展，提高现有火/储联合系统AGC调频能力以减轻电网调频负担成为研究热点。火电机组与储能在调节速率、跟踪能力及调节容量等方面各具优势，但若其性能优势与AGC工况特性匹配不当，则将导致因对调频源的不当使用或两类调频设备间的能量对冲而造成减弱调频能力的风险。本课题针对应用协同运行控制解决调频源的优势调节性能发挥及能量对冲等问题，通过适用于调频工况的储能系统外特性分析，建立具备同等AGC调频能力的储能功率/容量与火电机组的定量关系，充分掌握不同调频资源的调节性能；构建储能与火电机组状态空间耦合系统的微分博弈动态协同模型，分析火/储联合AGC调频系统的调节性能互补与对冲特性，动态协同运行特性与判据，以及多指标综合优化协同运行控制算法，以实现火电机组与储能系统的优化运行从而达到联合系统整体调频能力的提升，为促进调频资源的挖掘利用和提高电网调频能力提供技术思路。

随着储能辅助火电机组AGC调频示范工程的开展，具备同等调频能力的火/储容量间的定量关系、储能容量优化配置以及火储间的协同运行等技术逐渐受到业界关注。针对这些技术问题，在探讨电池储能系统（BESS）参与电网AGC调频的实现方法基础上，对与火电机组具备同等调频能力的BESS功率与容量进行配置；基于储能AGC调频应用场景中的运行曲线，提出一种基于时间序列关联分析并结合聚类法的典型工况提炼方法，并聚类出该工况下的两种运行特征曲线；针对当前储能容量配置存在的技术与经济性难以致衡的问题，建立了辅助单台机组AGC的储能运行层-经济层的双层容量配置模型，以达到储能投资成本低与机组调频性能提升高的博弈平衡；以储能对AGC指令与机组出力实时偏差量的补偿度为决策变量，以调频性能指标和储能电量平衡度最大化为目标，建立储能充放电策略实时优化模型，并通过仿真分析，验证了方法的可行性和有效性。.通过本研究，得出：（1）与火电机组具备同等AGC调频能力所需储能系统功率与AGC调频持续时间为线性关系，所需容量与AGC调频持续时间为二次函数关系，随着持续时间增长，所需功率与容量增大。（2）基于概率统计法和聚类分析法考察了储能调频工况中电池的分布变化规律及频次特性，储能电池出力工作模式划分，各工作模式的交互顺序与出现频次及对应的SOC运行轨迹，提出了持续充电与持续放电两种工况曲线。（3）仿真比对了容量双层优化策略与石景山策略下的BESS配置结果，文中策略通过减少寿命损耗，在寿命年限和年净收益之间取得制衡，提高了年净收益增量，减小了项目投资回收期。基于1000MW火电机组，储能配置的优化结果为22.3MW/18.4MWh，年净收益增量高出242.7万元。（4）设计的补偿度实时优化的火电-储能联合AGC调频策略，基于2台AGC机组数据的仿真实验结果表明，与其他策略相比，补偿度策略在具体场景下对储能可用率和调频性能改善明显，且短周期优化更利于性能和储能持续性的致衡。