Analysis of the Interoperability of Power-Electronic-Based Grid Converters

Among the variety of power system stability aspects, this thesis focuses on the low-frequency interactions between different converters in an AC power system. In particular, the general interoperability of grid-following and grid-forming converters is determined and presented. The analysis is based on different simulation domains as part of a multi-method scheme. As a foundation for this analysis, the converter characteristics of the two fundamental control types and their susceptibility to instability are revealed for basic setups. The most common control concepts are compared and analyzed. The results justify the consideration of generalized converter characteristics. Futhermore, the apperance of stability issues is studied for heterogeneous multi-parallel converter setups. A theory describing the interoperability of converter clusters is derived allowing to define benchmarks for grid-forming and grid-following converter controls. As a result, this thesis provides a deeper understanding of stability-critical converter networks, their physical mechanisms, and their dependencies on parameters and uncertainties