Synthesizing Delay-Robust Controllers for Low-Inertia Power Systems

In modern power systems, conventional power plants are increasingly being replaced by power-electronics-interfaced (renewable) generators. This results in a decrease of the available system inertia and can lead to much faster dynamics in the grid, rendering the current control and protection schemes inadequate. Recent advancements in communication technology and Wide-Area Monitoring and Control (WAMC) offer highly promising new opportunities for the deployment of communication-based control schemes, which can provide the performance and flexibility required in future low-inertia systems. A fundamental aspect in the practical implementation of such schemes is their robustness with respect to time-varying communication delays and exogenous disturbances. This problem is tackled in the present talk by providing delay-robust control design procedures for two emerging applications in low-inertia systems: wide-area oscillation damping and distributed secondary frequency control. The approaches are based on Lyapunov-Krasovskii functionals and formulated in terms of Linear-Matrix-Inequalities (LMIs).