This master’s thesis examines the impacts of outages of Slovenian 220 kV and 400 kV transmission lines on cross-border capacities at Slovenia’s borders within the context of Core capacity calculation region and flow-based methodology, where the cross-border capacity indicator is represented by the analytical indicator MaxBEX.
17 outage scenarios along with a reference scenario were simulated using the CCCt (Core Capacity Calculation Tool) for a period of three representative weeks in 2025 (a spring, summer and autumn week). The results were presented as a relative change in the indicator ΔMaxBEX [%] and analysed using distribution plots, statistical metrics, and comparative analyses across the observed borders, simulated weeks, and outage scenarios, including their characteristics. The impacts differ greatly between individual borders. Different outage scenarios can produce substantial negative or positive extreme values of ΔMaxBEX [%], however, most results lie within the range from −5% to +5%.
Auxiliary factors of negative impact were introduced to allow a global ranking and comparison of individual borders, outage scenarios and simulated weeks based on the impacts of outages on cross-border capacity. The results show that negative impacts on the indicator are larger at the borders with Austria and Hungary, while they are significantly smaller at the border with Croatia. The most substantial negative impact on the MaxBEX indicator is caused by the outage of the Maribor – Kainachtal transmission line, followed by the outages of Divača – Beričevo, Podlog – Cirkovce, and Cirkovce – Krško, whereas the smallest negative impact is observed for the Beričevo – Okroglo line outage. A clear weekly dependency of the results is also evident for some outage scenarios. This is most apparent for the Beričevo – Podlog line outage, which results in very negative impact in the first (spring) week, while its impact in the summer and autumn weeks is almost negligible. Based on transmission line characteristics, the results indicate a pattern in which outages of single-circuit 220 kV lines often result in positive ΔMaxBEX [%] values. However, this does not hold true for all scenarios and therefore cannot be used as a reliable way to predict line outage results.
Lastly, an optimisation of the planned outage schedule for 2025 was performed under the constraints that each outage is scheduled for a period of one week and that at most one planned outage is scheduled in any given week. The optimisation is based on auxiliary factors of market impact that combine the outage impacts on the MaxBEX indicator with actual 2025 market indicators obtained from the JAO Publication Tool (price spreads and scheduled exchanges). Two optimisation approaches were applied. The first considers only data on Slovenia’s borders, while the second considers data for the entire Core region. The resulting schedules are then compared. The results show that the choice of approach has a strong effect on the final proposed planned outage schedule, therefore the approach should be selected according to the objective of the analysis.
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