光储联合运行直流微电网控制策略

摘要

In order to solve the problem of photovoltaic (PV)grid-connection,the paper proposes a kind of control strategy for DC micro-grid operation based on PV and energy storage systems.It firstly constructs structure of the DC micro-grid sys-tem based on unified operation of PV and energy storage which consists of the PV system,the energy storage system,the non-isolated DC-DC converter and the high-frequency isolated DC-DC converter.By dividing six kinds of operation modes for the system and in the premise of ensuring stable DC busbar voltage,this strategy can determine operating state of the en-ergy storage system by detecting and comparing PV output power and load demand power in real time,which is to consider the energy storage system as the relaxation node of the DC micro-grid so as to ensure stable operation of the system.Finally, it verifies effectiveness of this system and the control strategy by PSCAD/EMTDC simulation.Meanwhile,it studies proto-type of the high-frequency isolated DC-DC converter,and the experimental results prove accuracy of theoretical analysis.%为了更好地解决光伏系统的并网问题,提出了一种基于光储联合运行的直流微电网运行控制策略.首先构建了光储联合运行的直流微电网系统结构,该系统由光伏系统、储能系统、非隔离型DC-DC变换器以及高频隔离型DC-DC变换器组成.在划分系统6种工作模式的基础上,该策略可以在保证直流母线电压稳定的前提下,通过实时检测并对比光伏输出功率与负荷需求功率来确定储能系统的工作状态,即采用储能系统来作为直流微电网的松弛节点,从而保证直流微电网系统的稳定运行.最后,基于PSCAD/EMTDC仿真软件验证了该系统以及运行控制策略的有效性,针对核心器件高频隔离型DC-DC变换器进行了样机实验研究,实验结果证明了理论分析的正确性.