面向电网二次调频的多类型储能集成控制策略及经济性评估

Integrated control strategy and economic evaluation of multi-type energy storage for power grid secondary frequency modulation

针对电网二次调频场景,提出了延长使用寿命的电池储能集成控制策略并对多类型储能进行经济性评估,以提高调频经济性。首先,基于区域控制偏差(area control error,ACE)控制搭建电池储能-常规机组参与电网二次调频模型,发挥储能频率快速响应特性。随后,将电池储能系统划分为充放电不同特性的两部分进行集成,并提出独立跟踪调频功率策略,减小调频过程中频繁充放电对电池寿命的影响以延长使用寿命。最后,拟合出多类型电池寿命曲线,并构建基于雨流计数法的电池储能寿命评估模型和全寿命周期成本模型,对比分析多类型电池储能集成控制下的经济性。基于实际负荷扰动的算例表明:所提集成控制策略可以有效延长调频场景下电池储能使用寿命,采用锂电池、铅酸电池和镍氢电池进行集成控制时,使用寿命分别延长了数倍;寿命周期成本显著降低。

To investigate the secondary frequency modulation scenario of the power grid,this study proposes the integrated control strategy of the battery energy storage with an extended service life and performs the economic evaluation of a multi-type energy storage to improve the frequency modulation economy.First,based on the area control error,a battery energyconventional unit in the grid's secondary frequency modulation model is built to play the fast response characteristic of the energy storage frequency.Next,the battery energy storage system is divided into two parts with different charge and discharge characteristics for integration.The independent tracking frequency modulation power strategy is then proposed to reduce the influence of the frequent charge and discharge on the battery life during the frequency modulation process and extend the service life.Finally,a multi-type battery life curve is fitted.A battery energy storage life evaluation model and a life cycle cost model based on the rainflow-counting method are constructed to compare and analyze the economies of the multi-type battery energy storage under integrated control.The numerical examples based on the actual load disturbance show that the proposed integrated control strategy effectively extends the service life of the battery energy storage in the frequency modulation scenario.The service life is extended several times with lithium and lead-acid batteries.In conclusion,the life cycle cost is significantly reduced.