Application of PSS to Improve the Stability of a Power System With a High Penetration of Renewable Energy

Sammanfattning: Unlike traditional power generation composed of synchronous generators, renewable energy in theform of solar and wind power does not add inertia to power systems. Therefore, as increasedproportions of renewable energy are added, the dynamics of the power system will be affected. In thisreport it is examined how power system stability can be improved when increasing amounts ofconverter-based renewable energy are introduced to Kundur's two-area system. The effects ontransient and small-signal stability are characterised and compared to a fully non-renewable systemusing the simulation programme SIMPOW. Thereafter, a power system stabiliser (PSS) based on acontrol-Lyapunov function (CLF) algorithm is utilised to improve power system stability anddamping. A methodology is developed to find a PSS tuning which suits varying placements andproportions of renewable energy throughout the system. Finally, the effects of adding a second PSSare examined and compared with those for a single PSS. The introduction of PSS tuned with thedeveloped methodology shows promise in improving system stability when renewable power sourcesare introduced. Future work may be directed into applying the methods presented on a larger grid, aswell further exploring the characteristics of a CLF-based approach.