EVALUATION OF DYNAMIC ACTIVE DISTRIBUTION NETWORK EQUIVALENTS WITH GRID FORMING CONVERTERS IN THE CONTEXT OF SYSTEM STABILITY STUDIES

Stability studies of future power systems that are dominated by converter-based generation, typically connected to the distribution system, require high computational effort. Equivalent dynamic models of distribution systems reproduce the dynamic behavior while reducing the complexity of the corresponding detailed network models. The Sensitivity-Technology-Control-Clustered Approach, introduced in previous work, is a method capable of creating equivalent dynamic models of distribution grids with both grid following and grid forming converters. For this work, a German transmission system area is modeled, and fourteen distribution grids are connected to several nodes of the transmission system. The distribution grids are represented by three grid models dominated by converter-based generation including grid forming converters. The Sensitivity-Technology-Control-Clustered Approach is applied to each detailed distribution network model and simulations are performed for a phase angle jump, a frequency jump and a short circuit fault. The dynamic behavior of each detailed network model is compared with the corresponding equivalent dynamic model by applying a suitable validation methodology. Results show that the detailed networks' dynamic behavior is reproduced accurately. Also, the model complexity of the detailed network models was reduced significantly. Hence, the Sensitivity-Technology-Control-Clustered Approach is a suitable method to create equivalent dynamic models in the context of system stability studies of future converter dominated networks.