Assessing Renewable Resource Penetration on Power System Small-Signal Reachability

This thesis proposes a method to assess the impact on power system dynamic performance caused by uncertainty in the system supply side. Operational uncertainty, e.g., demand variability, is not new to power systems. However, with the increased penetration of renewable-based generation, operational uncertainty will extend to a significant portion of the supply side, which may have an impact on system dynamic performance, e.g., frequency or voltage deviations beyond prescribed operational requirements. To address the problem, we propose the use of reachability analysis techniques, which provide bounds on worst-case deviations of system variables that must remain within certain operational constraints. We assume the input disturbance caused by the renewable-based generation is small enough to justify linearization of the power system around a nominal trajectory. If the reach set is within the region defined by system operational requirements, then we conclude the disturbance caused by the renewable resource does not have a significant impact on system dynamic performance. The method is illustrated with several case studies. In particular, we show the method successfully provides reachability results for a sizable benchmark system that contains 140 buses and 48 synchronous machines, which accounts for a total of 294 dynamic states