Abstract:

A hierarchical event-triggered control strategy involving the microgrid central control (MGCC) is proposed to address the issues of strong dependence on central controllers, high communication demand, and poor disturbance regulation ability in centralized control of hybrid microgrid, which effectively reduces the redundant communication in distributed clusters and the computational burden on central controllers, and improves the reliability of strategy. The proposed strategy divides the control system into two layers. The device layer is the local control layer, which adopts the distributed collaborative control. The designed local controller can locally control and update the output status, achieving decentralized and autonomous operation of the hybrid microgrid. In addition, a microgrid control layer is established in the control layer, and an event-triggered strategy is introduced to coordinate MGCC to obtain the global information of the hybrid microgrid and issue predefined control instructions to the local controllers, achieving the flexible scheduling of "source-grid-load-storage", especially in response to grid oscillations caused by unexpected events. Finally, a hybrid microgrid model is built using the Matlab for simulation and the Stateflow module is used to realize the event-triggered strategy, It is verified that the proposed control strategy can reduce the system communication traffic by 56.4% while meeting the reliability and stability of grid connection/island mode.

Key words: source-grid-load-storage microgrid, event-triggered strategy, hierarchical structure, microgrid central controller