Distributed balancing energy activation and exchange optimisation

Abstract

European balancing markets are presently fragmented and mostly national. Integrating them on common platforms requires the ability to identify optimal balancing energy volumes to be activated and exchanged to cover imbalances across the interconnected system, but this leads to new challenges. To avoid balancing energy flows compromising operational security, capacity limitations in the transmission network should be taken into account in the optimisation. However, a zonal market structure and limited computational time inhibit using detailed models in the optimisation. This study describes and demonstrates a distributed formulation for optimisation of activation and exchange of balancing energy. Using Benders decomposition, the optimisation is separated into local activation problems that are smaller and less complex, distributing the computational effort. A single exchange problem identifies the optimal exchange volumes between geographical areas using optimality cuts obtained in the local subproblems. The proposed formulation is capable of optimising balancing decisions across a large, interconnected system, while still keeping a zonal market structure and taking detailed network constraints into account.