针对平抑风光储联合发电系统输出功率波动问题,提出一种具有变权值自适应滤波的风光储协调优化控制策略。在传统的加权移动滤波算法基础上,分析了储能出力、波动率以及滤波带宽的关系,以储能系统的荷电状态(state of charge,SOC)平衡度指标和并网功率波动率作为约束条件实时调整加权移动滤波算法的权值与滤波带宽。在给定的波动率约束下,实现风光储联合发电系统协调优化控制。算例表明,所提出的变权值自适应滤波算法优于传统的一阶低通滤波风光功率平滑效果,在保证SOC合理水平前提下,有效平抑了风光联合输出功率的波动,降低了储能系统充放电次数,提高了储能系统的使用寿命。
考虑储能系统的充放电特性,根据电力系统所需要提高供电可靠性,结合随机生产模拟中得到的等效负荷持续曲线,确定储能系统的额定充放电功率和容量,在随机生产模拟计算中,考虑了表征供电可靠性的两个指标:电力不足概率(Loss of Load Probability,LOLP)和电量不足期望值(Energy Expectation not Served,EENS)。采用负荷标准差与电费综合评价削峰填谷的效果,以这两个指标作为削峰填谷优化数学模型的目标函数。
Battery energy storage system(BESS)is one of the effective technologies to deal with power fluctuation and intermittence resulting from grid integration of large renewable generations.In this paper,the system configuration of a China’s national renewable generation demonstration project combining a large-scale BESS with wind farm and photovoltaic(PV)power station,all coupled to a power transmission system,is introduced,and the key technologies including optimal control and management as well as operational status of this BESS are presented.Additionally,the technical benefits of such a large-scale BESS in dealing with power fluctuation and intermittence issues resulting from grid connection of large-scale renewable generation,and for improvement of operation characteristics of transmission grid,are discussed with relevant case studies.
