Mitigation of Communication Time Delay for Enhanced LFC of Interconnected Microgrid Systems Using Cascaded PD-ADRC Controller

Combining microgrids via tie-line results in the formation of an interconnected microgrid system to enhance power system resilience and efficient system operation. The large geographical coverage of interconnected microgrids leads to the inevitable occurrence of communication delays, as communication links are extensively used for the exchange of control and measurement signals. Communication delays pose a significant challenge to load frequency control (LFC) operations. This paper addresses the LFC in a two-area interconnected microgrid system with different levels of communication time delay. This work proposes an effective solution through a cascaded Proportional-Derivative disturbance rejection (PD-ADRC) controller design, simultaneously optimized using the MBO optimization technique. By analyzing the system performances, it becomes evident that the proposed cascaded PD-ADRC controller outperforms the traditional ADRC, in terms of overshoots, undershoots, settling time, and oscillation magnitudes, subjected to various levels of communication time delay.