Mehrstufige Ausbauplanung elektrischer Übertragungsnetze zur Ableitung bedarfsgerechter Transformationspfade

The decarbonization of the energy system is leading to a substitution of conventional power plants by renewable generation units mostly located far from load centers. Subsequently, the requirements for the transportation of electrical energy and thus for the installation of new transmission capacities increase significantly. Due to time intensive approval processes as well as a lack of public acceptance, it is necessary to meet the need for new transmission capacities by the reinforcement and optimization of the existing network structure as well as the exploitation of operational flexibility. Simultaneously, the ongoing transformation of the energy system causes permanently changing requirements, which can be captured by the investigation of phased planning stages within the planning horizon. Additionally, a foresighted planning method enables the anticipation of the need for new transmission capacities of upcoming stages at early ones to identify efficient multi-stage transformation paths. In this thesis, a multi-stage expansion planning method for the identification of efficient transformation paths of electrical transmission grids is developed. Intertemporal dependencies between phased planning stages as well as dependencies between expansion measures and operational flexibility are analyzed by an integrated and foresighted optimization of expansion planning and grid operation. The modelling approach aims at minimizing overall investment and operational costs while satisfying the N-1 criterion. The expansion portfolio includes classical AC expansion and reinforcement measures as well as power flow controlling devices such as high voltage direct current systems, phase shifting transformers and thyristor controlled series compensators. The integration of congestion management measures into the planning method such as redispatch of conventional power plants enables a further optimization of grid operation. Within exemplary results, the dependencies that are relevant for the identification of efficient transformation paths are analyzed. The benefit provided by a foresighted planning method is derived by comparing the transformation path identified by the developed approach with one determined by a sequential planning approach, which only takes the congestion situation at the current stage into account. The consideration of the complete expansion portfolio instead of a limited one reduces the overall investment and operational costs significantly. The methodological comparison between the developed approach and a recognized heuristic approach evidences the impact of a fully integrated optimization of expansion planning and grid operation