A Modular and Flexible Power System Test Grid for Stability and Protection Analysis of Converter-Dominated Grids

Abstract:
This paper introduces an advanced test grid model designed for comprehensive stability analysis in converter-dominated power systems. The model is highly modular and flexible, replicating medium-voltage industrial grids with the inclusion of synchronous generators, motors, and inverter-based resources (IBRs). Its adaptability enables detailed investigations into the effects of various IBR penetration levels on power system stability. The paper explores critical stability domains, including rotor angle, voltage, frequency, resonance, and converter-driven stability. Methodologies employed encompass time-domain simulations (EMT), impedance-based stability analysis, and Prony analysis. A notable feature of the grid model is its support for both grid-following and grid-forming inverters, integrated via a co-simulation interface to enable extensive simulations and analyses across multiple simulation solvers. An illustrative case study exemplifies the model's application, focusing on the small-signal stability of grid-following inverters through impedance-based stability analysis, corroborated with EMT simulations. This validation reaffirms the model's robustness and versatility. Significantly, this work enhances the understanding of and response strategies to the challenges posed by high IBR pen-etration in contemporary power systems. The insights and methodologies derived from this test grid model are pivotal for devising strategies that ensure stable and reliable operations in increasingly converter-dependent energy networks.