基于机组实时出力增量预测的火电–飞轮储能系统协同调频控制研究

Research on Coordinated Frequency Control of Thermal Power-flywheel Energy Storage System Based on the Real-time Prediction of Output Increment

新能源的大规模并网给电力系统的频率安全带来了严峻挑战,充分挖掘电源侧调频资源对提升电网支撑能力具有重要意义。火电机组-飞轮储能联合调频能较好解决新型电力系统带来的火电机组运行安全性和经济性等问题。作为当前电网调频主力,火电机组动态特性复杂,各动态工况下调频能力差别较大,联合调频系统的协同出力容易受到影响。因此,该文提出一种机组实时出力增量的量化预测模型,进而设计了火电-飞轮储能系统协同调频控制策略,实现了动态工况下飞轮储能出力的自适应调整。仿真验证表明,该文提出的预测模型能够准确预测动态工况下机组的调频能力,协同调频控制策略可以改善电网调频效果。相比于传统下垂控制,系统频率偏差的最大值降低32%,稳态偏差减少约30%。火电机组出力波动减少26%,有利于火电机组安全稳定运行。

With the large-scale grid integration of renewable energy,the frequency security of power system has been severely challenged.Fully exploiting the frequency modulation resources on the power supply side can improve the supporting capacity of power grid,which has great significance.The modern power system will seriously damage the safety and economy of the unit operation;the combined frequency modulation of the thermal power unit and flywheel energy storage can solve the problems effectively.As the main force of power grid frequency modulation,the dynamic characteristics of thermal power units are complex,and the frequency modulation capability varies greatly under different dynamic conditions,which influences the cooperative output of the combined frequency modulation system.Therefore,this paper proposes a quantitative prediction model of real-time output increment,and designs a coordinated frequency modulation control strategy for thermal power-flywheel energy storage system.This strategy could adaptively adjust the flywheel energy storage output under dynamic conditions.The simulation results verify that the proposed model can accurately predict the frequency modulation capability of the unit under dynamic conditions.The proposed strategy could improve the grid frequency modulation effect.Compared with traditional droop control,the maximum frequency deviation of the system is reduced by 32%,and the steady-state deviation is decreased by about 30%,respectively.The output fluctuation of thermal power unit is reduced by 26%,which is beneficial to the safety and stability of thermal power units.