基于孤岛模式下V/f控制的微电网系统研究

Island model V/f controlled micro grid system study

介绍了铅酸蓄电池的经典一阶模型及充放电电路的拓扑结构,并分别研究了有功和无功功率(PQ)源和V/f源储能系统下双向变流器的控制方式。结合西藏尼玛县可再生能源局域网建设项目背景,针对初期西藏尼玛县现场V/f源因过充或过放导致微电网溃网情况,提出一种基于孤岛模式下储能蓄电池的荷电状态SOC(State of Charge)稳定的控制策略,即控制V/f源下的蓄电池SOC在阈值附近小幅度波动,从而保持蓄电池小功率的充放电。基于EMTDC/PSCAD软件对系统进行仿真,结果表明了该控制策略的有效性,为孤岛模式下微电网的稳定运行提供了一种很好的解决方案。

This paper introduced lead-acid battery classic first order model and topological structure of charging and discharging circuit. Control method of bidirectional converter under active and positive power source and V/f source accumulation system was studied. Base on the incident of micro grid failure caused by V/f source over-charged,a stable state of charge( SOC) control strategy based on island mode was indicated. Which is keeping low rate charge and discharge by controlling the SOC to slightly fluctuate around threshold. The simulation on EMTDC/PSCAD software proved the effectiveness. This strategy provided a solution for the stability of micro grid under island mode.