基于分层控制的微网无缝切换研究

由分布式发电(DG)单元结合本地负载、储能设备等组成的微电网整合了各分布式发电单元的优势,减弱了对大电网的影响。微电网能够在并网模式与孤岛模式下运行:并网时,系统处于电流源型工作式模输出给定功率;孤岛运行时,DG单元需维持微电网电压和频率稳定。针对微网平滑切换控制方法进行了研究,提出一种适用于分层控制结构的新型控制器,通过控制前后两种控制器在切换瞬间的输出实现平缓变换,可削弱切换暂态过程影响、确保模式切换的平滑性,使系统稳定性得以提高。最后,建立微网系统实验平台对文中所提策略的有效性和可靠性进行实验验证。

Research of Hierarchical Control in Seamless Transition of Microgrid

Micro-grid consists of distributed generation( DG) , which is combined with local load and storage device, integrates the advantages of each proposed distributed generation units to reduce the impact on the grid.It can operate in islanding mode and grid-connected mode, when it is in grid-connected mode, the system works in current-mode, and outputs given power.While in islanding mode, it needs to maintain the stability of voltage and frequency of micro-grid.In view of the stratified control method, this paper proposes a new controller suitable for hierarchical control structure, and it can not only realize the smooth transformation, but also can weak the transient process effects, so the stability of system can be improved.Finally, the validity and reliability of the new controller are verified by establis-hing the experimental platform of micro-grid system.