基于直流微电网的混合储能协调控制策略仿真研究

摘要

Causing power imbalances within the system for the DC microgrid photovoltaic power generation unit of output volatility and intermittent,the coordinated control strategy of hybrid energy storage system based on DC bus voltage was proposed.The hybrid energy storage system could simultaneously take the advantages of high energy density and high power density.The strategy of the DC link voltage hierarchical control,using four threshold voltage was divided into five regions,with DC bus voltage as the information carrier,determined the operation state of the micro grid system,and realized the free switching between the charging and discharging modes of the hybrid energy storage unit.Hierarchical voltage control could effectively avoid the battery for the normal grid voltage fluctuations and frequent of charge discharge switch,further extending the service life of the battery.Finally,the simulation results of MATLAB/Simulink verified the feasibility of the proposed control strategy.%针对直流微电网中光伏发电单元出力的波动性和间歇性造成系统内部功率不平衡的问题,混合储能系统可以同时发挥蓄电池高能量密度和超级电容高功率密度的优势,根据直流母线电压进行混合储能单元间的协调控制策略.该策略将直流母线电压进行分层控制,采用四个电压阈值共分成五个控制区域,以直流母线电压为信息载体,决定储能系统的运行状态,实现对混合储能单元的充电、放电模式间自主切换.电压分层控制有效地避免了蓄电池由于电压波动而频繁进行充放电切换,从而延长了电池的使用寿命.最后,MATLAB/Simulink的仿真结果验证了所提控制策略的可行性.