Stability Analysis of Load Frequency Control for Shipboard Microgrids With Occasional Large Delays

This brief investigates stability analysis of delayed load frequency control (LFC) system for shipboard microgrids (MG). Different from the previous works, a time-varying delay with occasional large value in a few time intervals is studied. Firstly, by dividing the delay into two regions, the LFC of shipboard MG is modeled as a linear system with a switched delay. Then, a stability criterion is proposed to analyze the relationship between the exponential stability of system and the length/frequency of large delay. Finally, a case study shows that the system may still remain stable for the large delay satisfying specific conditions, which illustrates the effectiveness and advantages of the proposed method.