Reduction of Redispatch in Germany Using Dynamic Capacity of Embedded HVDC Systems

Inhalt:
HVDC systems could temporarily operate close to their physical limits by exceeding their guaranteed power limits. This additional transmission capacity, known as dynamic capacity, can be used for various use cases in the electric transmission grid. This paper investigates the use of dynamic capacity for curative congestion management. Therefore, an example of how dynamic capacity can be considered for curative congestion management in system operation is presented. In contrast to previous work, the impact on preventive redispatch and curtailment of renewable feed-in is quantified on the basis of a grid study. The impact on preventive redispatch is calculated using a grid planning tool, which includes a redispatch optimisation. The tool considers the (N-1) criterion for congestion management and calculates the redispatch volumes based on a future generation and load scenario, Scenario C, as well as the planned grid development being the target network of the German grid development plan 2035. It distinguishes between the effect of curative congestion manage-ment up to the nominal power limits of the HVDC and the additional effect of dynamic capacity. The impact on congestion management is used for an economic and environmental assessment of dynamic capacity. The results of applying dynamic capacity to selected HVDC links shows a potential of redispatch volume and renewable curtailment reduction of 5 % and avoided CO2 emissions between 3 % and 7 % compared to a reference case.