Frequency control of hybrid wind-hydro power plants with long conduits in isolated power systems

Abstract

The increase in the penetration of renewable energy is a reality in the vast majority of countries, both in Europe and in the rest of the world. This increase is not only occurring in continental power systems, but also on small islands that have high wind and/or solar potential. However, a high renewable energy penetration may compromise the stability of power systems, especially in the case of islands, which constitute isolated power systems. This is due to the inherent characteristics of renewable resources (uncertainty, intermittency and independence between availability and demand). These drawbacks are amplified by the power system inertia reduction caused by the fact that renewable generators are normally decoupled from the grid through a power electronics interface that do not add inertia to the system. It is well known that the long-term variability of renewable energy is well managed by pumped storage hydropower plants (PSHP). Thus, PSHP play an important role in the renewable resources integration,

Analysis of alternative frequency control schemes for increasing renewable energy penetration in El Hierro Island power system

“…This way renewable energy participation would be increased. The control schemes are developed using (i) pumping station regulation capacity (Energies), (ii) kinetic energy stored in the Variable Speed Wind Turbines (VSWTs) [20] rotors and (iii) a new Flywheel Energy Storage System (FESS) [8] connected to the grid through power electronics. Eight different control cases have been presented resulting of the combination of these control approaches.…”