基于使用寿命模型的大容量电池储能系统变步长优化控制方法

大容量电池储能系统(BESS)配合风电场调度可以提高风电场的可调性。为了研究延长BESS使用寿命的控制方法,建立了多因素聚合寿命模型,该模型考虑了大容量BESS的串并联特性和充放电特性,能够反映充放电倍率、控制步长、充放电次数和温度等多种因素对电池老化的影响。讨论了BESS控制步长和调度周期对BESS使用寿命和并网跟踪性能的影响,提出了BESS的变步长优化控制方法。设计了模糊变步长控制器,根据当前BESS的充放电倍率和跟踪性能指标实时调节控制步长。算例仿真表明,所提模糊变步长优化控制方法结合了大步长下使用寿命长和小步长下跟踪性能好的优点,并网功率能够较好地跟踪调度指令,实现了风电场的可调性,同时提高了BESS的使用年限。

Variable Step-Size Control Method of Large Capacity Battery Energy Storage System Based on the Life Model

Battery energy storage system (BESS) can improve the schedule ability of wind power. In order to study the control method of BESS life extension, a multifactor life model is developed considering series/parallel and charge/discharge characteristics of BESS. This proposed model can represent the effects on BESS aging, such as charge/discharge rate, control step-size, charge/discharge time and temperature. A variable step-size control method is proposed, after discussing the effects of the control step-size and the dispatch period on BESS life and the fluctuation index. A fuzzy variable step-size controller is designed to adjust the step-size according to charge/discharge rate and fluctuation index. Results indicate that the proposed control strategy combines the longer life feature under large step-size with less volatile feature under small step-size, which enables the power injected to the grid to track the dispatch orders well and the wind farm to be schedulable. Meanwhile, the proposed strategy can improve the life of BESS.