基于分层控制的并网控制策略研究

Research on Grid-Connected Operation Control Strategy Based on Hierarchical Control

传统分层控制结合主从控制与对等控制两者的诸多优点,但微源层与能量管理层之间结构的连接与并网过程的控制细节仍有缺陷。为了完善分层控制策略,在传统分层控制基础上提出了两个改进点:下垂控制中加入并网功率调节,通过PI控制器,实现对三级控制指令的下达;在并网预同步器中加入了相角偏差判定环节,减小相角变化过程带来的频率波动。在Simulink平台下,对传统和改进分层控制策略进行仿真分析,结果表明该方法改善了传统分层控制的层间衔接,且并网表现良好,能够提高系统稳定性。

The traditional hierarchical control combines the advantages of master- slave control strategy and peer control strategy, but the connections between the control layer of distributed generation and the energy management system and details of the transition between grid-connected and islanding operation is still flawed. In order to improve the hierarchical control strategy, based on the traditional hierarchical control proposed two improvements： The grid-connected power regulation was added in Droop control through the PI controller to achieve the instruction of tertiary control issued. The decision process of phase deviation was added in grid-connected pre-synchronizer to reduce frequency fluctuation when phase changed. In the Simulink platform, the improved hierarchical control strategy and the traditional hierarchical control strategy was simulated and analyzed. The results show that the method can improve the layer＇ s connectivity of the traditional hierarchical control and improve the stability of the system.