Novel Approach for Flexibility Aggregation at Multiple Vertical TSO-DSO Interconnections

Abstract:
Aggregation methods can be used to provide active and reactive power flexibility from the distribution grid level for the transmission grid level. This paper focuses on the voltage dependency of the aggregation methods under consideration of multiple vertical interconnections. First, limitations of existing methods are highlighted in a literature review. Subsequently, a novel aggregation method in which the voltage dependence is implicitly taken into account is developed. Using a test grid with two vertical interconnections, the accuracy of the novel aggregation method is demonstrated. The complete grid model served as a benchmark. Evaluation criteria are the estimation of the maximum and minimum flexibility exchange and the possibility to consider grid constraints of the distribution grid. The results show promising behaviour of the new aggregation method if a suitable parameterisation is applied.