Investigating Network Topology Optimization in the German Transmission Grid Using Real Operational Planning Data

Inhalt:
Optimizing topological measures in transmission grids with the aim of reducing grid congestions is a computationally complex challenge. The complexity is mainly driven by the discrete nature of switching measures, their combinatorial difficulty and non-linear powerflow impact. The integration of network topology optimization into real congestion management in the context of operational planning requires the consideration of additional technical and operational constraints, as topological measures have a greater influence on crucial grid limits, e.g. voltage angle differences, than other measures. Therefore, in this paper topological degrees of freedom and crucial technical and operational constraints for practicable topological measures are identified. Moreover, an existing framework for the cooptimization of topology and redispatch is further developed and applied to real operational planning data of the German transmission grid. The proposed method considers a subset of the identified technical and operational constraints. It employs a heuristic topology preselection with a subsequent redispatch optimization that also elects topologies. Exemplary results show high theoretical potential of network topology optimization reaching 50.7 % objective value reduction. Comparison to real day-ahead planned topological measures shows that current German processes already realize approx. 70%of this theoretical reduction potential, while having substantially less realization effort. Introducing a minimum switching duration generates more practicable switching suggestions, but does not reach performance of topological measures planned in reality. In summary, the proposed method shows great theoretical potential, but needs to be further developed for practicability.