柔性直流互联孤岛微网群的分布式频率协同控制

Distributed Cooperative Frequency Control for Flexible DC Interconnected Island Microgrid Cluster

柔性直流输电是解决多个微网集成聚合问题的最佳选择之一,但传统控制下,直流输电会导致微网间频率解耦,使微网间无法形成频率支撑。为此,以一致性理论为基础,提出一种全新的分布式频率控制结构,并设计了与之匹配的协同控制策略。在该策略中,通过微网间的接口换流站来实现微网间频率调控目标,并利用微网内分布式单元间的协作解决微网内频率恢复、备用容量精确分配等调控问题。控制策略在系统中的稳定性通过Lyapunov直接法进行了论证。最后,通过仿真验证了所提策略的有效性和"即插即用"性能。

Flexible DC transmission is one of the best choices for solving the integration and aggregation problem of multiple microgrids.However,under the traditional control,DC transmission will cause frequency decoupling among microgrids,which makes them unable to form frequency support with each other.To solve this issue,based on the consistency theory,a new distributed frequency control structure is proposed.Then,a coordinated control strategy matching with the structure is designed.In this strategy,through the cooperation of interface converter stations,the objectives of frequency regulation among microgrids can be achieved.Meanwhile,with the cooperation between distributed generators in microgrids,the issues such as frequency restoration and accurate allocation of reserve capacity are effectively solved.The stability of the proposed control strategy in the system is demonstrated by the Lyapunov direct method.Finally,the simulation verifies the effectiveness and"plug and play"performance of the proposed strategy.