Design of ISE-based frequency regulation scheme for airport microgrids using FOPDT approximation and reaction curve method

This article addresses the frequency control challenges of airport-centric microgrids (ACMs) through an integral square error (ISE) based control strategy. The dynamic behavior of the islanded ACM is first modeled using a linearized transfer function, capturing essential system properties. To simplify controller design and analysis, the model is approximated using a first-order plus dead time (FOPDT) approach based on the reaction curve method. Two PID controllers are then developed targeting different objectives: set-point tracking (SPT) to maintain desired frequency values, and load disturbance rejection (LDR) to counteract the impact of varying load demands. Qualitative performance comparison in terms of step responses is carried out for both modes. Additionally, quantitative performance comparison in terms of error indices and time-domain measures is also performed. Comparative simulations demonstrate that the SPT-oriented controller yields better transient performance and reduced cumulative frequency deviation compared to the LDR-based controller. The results highlight the effectiveness of integrating reaction curve modeling and ISE-driven tuning to achieve reliable and precise frequency regulation in islanded ACMs.