直流微网系统的多模态运行控制

Multi-mode Operation Control of DC Microgrid System

详细分析了系统处于并网和孤岛模式的运行情况,归纳设计了系统的9种工作模态,并针对每一种工作模态提出基于本地信息的系统整体协调控制策略,来协调光伏接口、储能接口及网侧接口的工作方式,旨在保证直流母线电压维持恒定,确保对电压变化敏感的重要负荷(如恒功率负载)的可靠供电和系统的能量平衡及稳定运行。根据电网状态、分布式电源输出功率与负载需求关系、蓄电池荷电状态等本地信息,决定系统的工作模态及模态间切换,所提控制策略有效维持了直流母线电压的恒定,实现了直流微网系统的运营可靠性。最后利用Matlab/Simulink进行仿真研究,结果验证了所提方案的有效性。

9 kinds of operation modes are designed after detailed analyzing the grid-connected and islanded operation condition.For each operation mode,a coordinated control scheme for whole system based on local information is proposed to coordinate working modes between PV interface,battery energy storage interface and the netside interface,which can guarantee the DC bus voltage maintain constant,thus to ensure reliable power supply for critical loads that are sensitive to voltage changes（such as constant power load（CPL））and the operation stability and power balance of system.Such local information as the state of power grid,the relationship between DG power output and loads demand and the SOC of battery decides the operation modes and conversion between different modes of the system.The proposed control scheme can maintain the DC bus voltage constant effectively,which realizes reliable operation of the DC microgrid system.In the end,simulations are carried out in Matlab/Simulink simulation environment,and the results verify the effectiveness of proposed scheme.