孤岛微网分层分布式频率调节及功率优化控制

为提高微网频率调节和功率优化性能,提出一种两层控制结构。为适应这一结构,初级控制由传统的功率-频率下垂改进为功率-增量因子下垂。第2层控制采用一致性协议以分布式方式实现频率同步、频率无差、功率优化目标。此外,针对功率约束问题,分析发现只采用饱和器会导致频率无差和功率优化目标间的冲突,为解决这一冲突,提出相应的功率约束控制方法。通过Lyapunov直接法论证了所提控制策略在系统中的稳定性。最后,采用5节点孤岛微网仿真算例验证了所提策略的有效性。

Hierarchical Distributed Frequency Regulation and Power Optimization Control for Island Microgrid

In order to improve the performance of frequency regulation and power optimization for microgrid, a two-layer control structure is proposed, in which the primary control converts the traditional power-frequency droop into the power-increment factor droop to accommodate this structure. The secondary control uses a consensus protocol to achieve the goals of frequency synchronization, frequency no-difference and power optimization in a distributed manner. In addition, it is found that if only the saturator is used for power constraint, it will lead to conflicts between frequency regulation and power optimization. To solve this conflict, a corresponding power constraint control method is proposed. The stability of the proposed control strategy in the system is demonstrated by the Lyapunov direct method. Finally, the effectiveness of the strategy is verified by a simulation example of 5-node islanded microgrid.