基于二阶滤波的混合储能系统能量管理控制策略

ENERGY MANAGEMENT CONTROL STRATEGY OF HYBRID ENERGY STORAGE SYSTEM BASED ON SECOND-ORDER FILTERING

针对由超级电容器与蓄电池储能构成的混合储能系统,提出一种基于改进型二阶滤波功率分配的荷电状态(state of charge,SOC)恢复控制策略。首先,分析传统一阶低通滤波算法的功率分配过程,构造具有功率误差反馈环的二阶滤波传递函数,消除传统一阶低通滤波器在响应高频功率指令时的积分作用,改善混合储能系统对目标功率指令的跟踪控制效果。然后,以归一化后的混合储能系统SOC为控制指标,制定滤波时间常数新型调整规则,动态优化混合储能系统功率分配指令。仿真结果表明,该控制策略可有效平抑风电并网功率波动,最大化利用超级电容储能可用容量,同时延长蓄电池使用寿命。

A state of charge(SOC)recovery control strategy based on improved second-order filter power allocation is proposed for hybrid energy storage system composed of supercapacitor and battery energy storage. Firstly,the power allocation process of the traditional first-order low-pass filter algorithm is analyzed,and the second-order filter transfer function with power error feedback loop is constructed to eliminate the integral effect of the traditional first-order low-pass filter in response to the high frequency power instruction and improve the tracking control effect of the hybrid energy storage system on the target power instruction. Then,taking the normalized SOC of hybrid energy storage system as the control index,a new adjustment rule of filtering time constant is formulated to dynamically optimize the power allocation command of hybrid energy storage system. The simulation results show that the control strategy can effectively suppress the fluctuation of wind power grid-connected power,maximize the available capacity of supercapacitor energy storage,and prolong the service life of battery.