A loop flow analysis in the power transmission grid using power flow colouring and generation shift key optimisation

Abstract

In order to achieve the European climate targets, the use of renewable energies must be significantly expanded. The associated volatility in the generation leads to more and more congestions in the transmission grid, which have to be solved at considerable cost. In order to distribute the costs incurred among the transmission system operators (TSOs), the European Union has directed the TSOs to develop a Cost Sharing methodology. The allocation of costs is based on the polluter pays principle. This means that the originators of loop flows are identified and are responsible for bearing the associated costs. This thesis examines the impact of Generation Shift Keys (GSKs) on loop flow calculations, employing the Power Flow Colouring (PFC) method. Subsequently, this study will address the impact of these results on the cost calculation using the Core Cost Sharing method. The research compares various GSK strategies with a view to determining their impact on loop flow results for critical network elements around Austria. These include the Proportional to Generation GSK, a Unified GSK and the Dynamic GSK employed by APG. A key objective of this thesis is to develop and evaluate an Optimised GSK that minimises the loop flows and costs determined in the Core Cost Sharing method. The results demonstrate that the selection of GSK can have a significant impact on the outcomes of loop flow calculations and cost sharing, and that optimisation can result in a substantial reduction of loop flows and costs. The findings assist in enhancing grid management and also provide valuable insights into the functioning of the PFC method and for the development of future GSK methods. In conclusion, the implications for grid strategy are identified and potential avenues for further research are proposed, with a particular focus on the optimisation of GSKs under diverse grid conditions.