基于FCS-MPC的分布式HESS功率协调控制

DISTRIBUTED HYBRID ENERGY STORAGE SYSTEM POWER COORDINATION CONTROL BASED ON FCS-MPC

针对孤岛直流微电网中分布式混合储能系统(HESS)协调运行问题,提出一种基于有限控制集模型预测控制(FCSMPC)的功率协调控制策略。该策略采用小波包变换来分解分布式HESS的功率需求,由于分解后信号的特点和分布式HESS中蓄电池初始状态的不同,于是对分解后最低频信号基于蓄电池荷电状态(SOC)设计自适应因数来进一步再分解。由于DC/DC变换器开关状态组合数量较少,使得多步FCS-MPC的滚动优化计算量较少,于是采用FCS-MPC取代双闭环PI控制,提高系统动态响应。搭建含有分布式HESS的孤岛直流微电网模型,并做了3种方案的仿真对比,验证该策略有效平缓了直流母线波动并实现蓄电池SOC一致。该策略有利于提高电网运行的稳定性,并延长蓄电池使用寿命。

Aiming at the problem of coordinating operation of distributed hybrid energy storage system(HESS)in the isolated DC microgrid,a power coordinating control strategy based on finite control set-model predictive control(FCS-MPC)is proposeed.This strategy uses wavelet packet transform to decompose the power demand of distributed HESS,and due to the characteristics of the decomposed signal and the difference in the initial state of the battery in distributed HESS,so the adaptive factor pair is designed based on the state of charge(SOC)of the battery to further decompose the lowest frequency signal after decomposition.Due to the small number of switching state combinations of DC/DC converters,the rolling optimization calculation of multi-step FCS-MPC is less,so FCS-MPC is used to replace the dual closed-loop PI control to improve the dynamic response of the system.In this paper,an islanded DC microgrid model containing distributed HESS is constructed,and the simulation comparison of the three schemes is made,which verifies that the strategy effectively smooths the DC bus fluctuation and realizes the consistency of battery SOC.This strategy is conducive to improving the stability of grid operation and extending the service life of the battery.