Observer-Based Finite-Time Fuzzy Load Frequency Control for Multiarea Nonlinear Power Systems Under Input Delays and Cyber Attacks

This paper presents an observer-based finite-time fuzzy load frequency control (LFC) strategy for multiarea nonlinear power systems with uncertain parameters, considering the impact of cyber attacks and input delays. To tackle the nonlinearities and uncertainties, an LFC model incorporating multiple input delays is developed within the interval type-2 (IT2) Takagi-Sugeno (T-S) fuzzy framework. In response to unmeasurable states and unknown false data injection attacks (FDIAs), state and attack observers are designed to estimate these unknowns, thereby enabling effective compensation for FDIAs during the controller design. Furthermore, an observer-based reduction method is employed to transform the multiple input-delay system into a delay-free one, which reduces conservatism. Sufficient conditions are derived such that the closed-loop system is finite-time stable with $H_{\infty }$ performance. Finally, simulations demonstrate the effectiveness of the proposed method.