基于一致性算法的独立直流微电网分层协调控制策略

Consensus-based Hierarchical Coordinated Control for Autonomous DC Microgrid

针对独立运行的直流微电网,提出了一种适用于含光伏和储能的分层分布式协调控制策略。多个储能单元采用分层控制方法以维持直流母线电压的稳定,第1层控制采用适应性下垂控制方法,下垂系数可根据储能电荷状态和额定功率进行自适应调整以平衡蓄电池的荷电状态;第2层控制采用基于离散一致性算法的二次电压恢复和电流均分控制,仅通过与邻居节点间的通信实现母线电压调节和电流均分。为实现储能和光伏协调控制,光伏单元不仅能自动改变控制模式以保证直流微电网功率平衡,还能根据储能单元运行状态参与直流母线电压的二次调节,使直流母线电压恢复到额定值附近。最后,通过实验验证了所提控制策略的有效性。

A hierarchical distributed coordinated control strategy between photovoltaic(PV)and energy storage units(ESUs)is proposed for an autonomous DC microgrid.Hierarchical control method is adopted for multiple ESUs to keep the DC bus voltage stable.On the primary level,adaptive droop control method is introduced to balance the state of charge(SOC)of batteries with droop coefficients,which are regulated adaptively according to the SOC and rated power of ESUs.On the secondary level,secondary voltage recovery and current-sharing control are adopted based on discrete consensus algorithm,and the regulation of bus voltage and current-sharing can be realized only through communications between neighboring nodes.Besides,to realize a coordinated control over ESUs and PV units,the PV unit can not only change its control mode automatically to guarantee a power balance of DC microgrid,but also participate in the secondary regulation of DC bus voltage according to the SOC of ESUs till the voltage is recovered to its rated value approximately.At last,the effectiveness of the proposed control strategy was verified by experiments.