微电网孤岛状态下新型混合储能控制策略研究

分析了微电网孤岛运行状态与并网运行状态储能系统控制策略的差异,针对孤岛运行状态,提出一种新型蓄电池-超级电容混合储能系统控制策略,针对传统控制策略在超级电容容量达到阈值而无法正常工作时,不能保证母线电压稳定,以及逻辑判断与数字滤波环节过多,响应速度慢、较难实现等问题,采用双电压闭环控制策略,配合利用双向DC/DC变换器自带的LC滤波器,省去数字滤波环节,在超级电容剩余电量达到限定值时,无需改变控制模式,仍能维持母线电压的稳定,提高了微电网可靠性。分别通过频域分析、仿真分析和实验研究,验证了所提控制策略的正确性与可行性。

Control strategy of hybrid energy storage under microgrid islanding operation state

Differences of energy storage system control strategy between islanding operation state and islanding operation state were analyzed,and a new battery-super capacitor hybrid energy storage system control strategy was proposed for the islanding operation state.For traditional control strategy,it cannot stabilize bus voltage when the ultra capacitor reach the threshold and cannot function properly,moreover,its response speed is slow and is difficultly implemented due to its over many logic and digital filters.Thus,a double voltage closed-loop control strategy combined with the use of LC filter in bi-directional DC/DC converter was employed,which spared the digital filters.When the remaining battery of super capacitor reached the threshold,it can stabilize bus voltage without changing control mode,which developed the reliability of micro-grid.Finally,the correctness and feasibility of proposed control strategy was verified by frequency analysis,simulation analysis and experimental studies.