Observer-Based Non-Fragile Intermittent Control for VSC-MTDC Under Non-Ideal Communication Channel

Multi-terminal direct current transmission (MTDC) systems, which rely on voltage source converters (VSC), have emerged as the premier solution for connecting offshore wind farms across vast distances. Nevertheless, the integration of VSC and MTDC with offshore wind farms is susceptible to various in-terferences and network security hazards. One significant threat is the Denial-of-Service (DoS) attacks, capable of disrupting measurement signals and inducing instability within the VSC-MTDC systems. Therefore, ensuring the seamless observation of system measurement signals is imperative. To tackle this challenge, this paper introduces a semi-aperiodic <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{DoS}$</tex> attack model and develops a non-fragile observer with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$H_{\infty}$</tex> stability. Our proposed approach establishes two sufficient conditions leveraging the time-varying Lyapunov function, and its efficacy is corroborated through numerical simulations.