Cyber‐Resilient MMC‐MTDC Stability via Robust Observer Design for Wind‐Integrated Grids
Abstract
ABSTRACT This paper proposes a stochastic stabilising control method, based on a Markov jump model (MJM), to comprehensively address stability challenges in modular multilevel converter‐based multi‐terminal direct current (MMC‐MTDC) systems due to communication network disturbances. The core idea is to design a robust control system minimising detrimental effects of time delays and Denial‐of‐Service (DoS) attacks. The significance arises from MMC‐MTDC systems with inertia support capability playing a critical role in modern power grid stability, especially when connected to doubly fed induction generator (DFIG)‐based wind farms, demanding assured stable operation. To achieve this, the paper first presents an MJM for MMC‐MTDC systems under random disturbances, modelling communication delays and DoS attacks with their probabilities. A second‐order communication disturbance observer then compensates for time delay effects as equivalent input disturbance, without needing precise delay magnitude. Additionally, a finite‐time stabilising controller based on MJM is designed to mitigate random DoS attacks. MATLAB/Simulink simulations clearly demonstrate the proposed method's efficacy in preserving system stability and rapidly restoring AC grid frequency under various conditions, including wind power unit uncertainties and power system dynamics.