Alternative control schemes of Pelton turbines to increase the integration of variable renewable energy sources

This paper proposes innovative control schemes for Pelton turbines to improve frequency regulation in isolated power systems with high penetration of variable renewable energy sources (vRESs). Traditionally, Pelton turbine deflectors are used as safety mechanisms; however, this study explores their potential for continuous frequency regulation, alongside the conventional needle control. The proposed strategies, including a deflector-based control and a mixed control (combining both injector as well as deflector actions), aim to address the limitations of traditional methods. The results obtained from dynamic model simulations demonstrate significant improvements in system performance and stability compared with the traditional needle-based control. In particular, the mixed control strategy achieves a balanced solution, minimizing frequency deviations, reducing water losses, and maximizing renewable energy integration. These findings highlight the potential of advanced turbine control to optimize the operation of isolated power systems and support the transition to sustainable energy systems.