为同时满足直流微电网中不同容量储能单元输出电流精确分配及荷电状态均衡的要求,在传统下垂控制的基础上提出一种基于一致性算法的改进下垂控制.将下垂系数与分布式储能单元(Distributed energy storage unit,DESU)相对容量因子及荷电状态(State of charge,SOC)相关联,消除不同容量对SOC均衡的影响,在充放电过程中实现SOC均衡,且为提高SOC均衡速度,在一致性算法中加入状态预测器,以提高 SOC 均衡速度;同时设计电压均衡器,对母线电压进行补偿,解决母线电压偏离额定值的问题.为验证所提策略的有效性,在Matlab/Simulink中搭建仿真模型,结果表明,所提策略实现了DESU间SOC的均衡及电流合理分配的目标,与此同时提高了SOC均衡速度.
State of Charge Equalization Strategy of Multi-storage Units with Different Capacities
In order to simultaneously achieve accurate distribution of output current and state of charge(SOC)equalization of different capacity energy storage units(ESUs)in DC microgrid,on the basis of traditional droop control,a droop control based on a consistent algorithm is proposed.It will be as sociated with the droop coefficient with the relative capacity factor of distributed energy storage unit(DESU)and the SOC to eliminate the influence of different capacities on SOC equalization so as to achieve SOC equalization during charging and discharging.And in order to improve the SOC equalization speed,the state predictor is added to the multi-intelligent algorithm to ensure that the SOC equalization speed is effectively improved on the basis of implementing control performance.The voltage equalizer is designed to compensate the bus voltage to solve the problem of bus voltage deviation from the rated value.To verify the effectiveness of the proposed strategy,a simulation model is built in Matlab/Simulink.The simulation results prove that the proposed strategy achieves the objectives of SOC equalization among ESUs,accurate current distribution and small bus voltage deviation.At the same time,the SOC equilibrium speed is increased.
DC microgridstate of chargedroop controlSOC equalizermulti-intelligent consistency algorithm
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