Extensive frequency response and inertia analysis under high renewable energy source integration scenarios: application to the European interconnected power system

Traditionally, power system's inertia has been estimated according to the rotating masses directly connected to the grid. Due to the significant penetration of renewable generation units, the conventional grid inertia is decreasing, subsequently affecting both reliability analysis and grid stability. As a result, concepts such as 'synthetic inertia', 'hidden inertia' or 'virtual inertia', together with alternative spinning reserves, are currently under discussion. Under this new framework, an algorithm to estimate the minimum inertia needed to fulfil the European network of transmission system operators for electricity requirements for rate of change of frequency values is proposed and assessed. Both inertia and additional active power can come from different sources, such as storage solutions, renewable sources decoupled from the grid, interconnections, or a combination of them. The power system under consideration includes thermal, hydro-power plants, and renewable generation units, in line with the most current and future European power systems. More than 700 generation mix scenarios are simulated, varying the renewable integration, the power imbalance, and the inertia constant of conventional power plants. The solutions studied here provide important information to ease the massive integration of renewable resources, without reducing the grid capacity in terms of stability and response to contingencies.