Analysis of classical SISO POD controller robustness for inter-area oscillations damping

To date, Power System Stabilizers (PSS) installed on synchronous generators have been the primary means of enhancing inter-area oscillation damping. However, with the growing penetration of Power Electronic Interfaced Resources (PEIR), there is increasing interest in leveraging these assets to support small-signal stability, notably through the integration of

Power Oscillation Damping (POD) controllers. The Requirement for Generator grid code, established by the European Commission, provide TSOs with the possibility to require such a capability from PEIR. However, applying this requirement to a large number of units implies ensuring that both the requirement itself and its associated conformity assessment procedure enforce a robust tuning of POD controllers across different operating points, locations, and modes. This is particularly challenging given that the conformity assessment is typically based on a simplified test case representing a fixed configuration of the asset. By analyzing eigenvalue sensitivities at different grid locations and under varying operating conditions for both small and large systems, this work aims to highlight the challenges inherent to this approach and the difficulties in achieving a robust POD SISO controller through a uniform compliance assessment framework. It also contributes to opening new directions for research by demonstrating that a certain consistency can exist for some SISO combinations and specific areas of the network.