A Hyperbolic Reduced-Order Nonlinear Disturbance Rejection Control Application for Delayed Hybrid Microgrid with Non-Linearity and Cyber-Attack

In modern-day, real-time challenges are increasing in Load frequency control (LFC). This work presents a novel reduced-order generalized active disturbance rejection control (RGADRC) strategy. The generalized structure of ADRC incorporates detailed plant information in the design. The proposed work incorporates an innovative hyperbolic non-linear error function in a reduced-order extended state observer (RESO). This refinement in observer gain due to non-linear gain variation improves the time domain specification of the response, specifically in terms of overshoot, settling time, and error indices. The proposed approach is simulated for various delayed single area non-reheat and reheat systems, including non-linearities like Generation rate constraint (GRC) and Governor dead band (GDB). Further, the proposed strategy is extended for two-area PV-thermal hybrid systems with non-linearity, and a practical IEEE 39 Bus New England system, which is a widely used benchmark system in power system studies. The robustness of this method is analyzed under the condition of +50% parametric uncertainty in gain and time constant simultaneously. This design technique effectively manages non-linearities, constant, and varying time delays, and assesses cyber-attack vulnerabilities. Further, the real-time challenges in the IEEE system are studied for multistep load variations with communication delay.