Rajasiirtokapasiteettien laskentamenetelmän kehittäminen

As European Union published the capacity allocation and congestion management guideline, the goal was to publish a guideline which would, among others, optimise the use of the power grid as well as the calculation and allocation of the cross border capacities. The guideline requires a coordinated manner to calculate the cross borders within transmission system operators as well as increase the frequency of the capacity calculation. Based on these objectives the currently in use capacity calculation methodology has to be developed to be in line with capacity allocation and congestion management guideline. The calculation methodology developed in this thesis utilises the NTC-method, which is currently in use, as a theoretical base. In the future this methodology is required to calculate capacities hourly for the whole Nordic synchronous area. This sets a strict operational environment for the CNTC method, in which the methodology is meant to calculate secure values fast. CNTC method was developed to utilise a simulation environment, which is used in Fingrid’s current capacity calculation. The method is divided into three main parts, which creates the base for the calculated technical maximum capacities. In the first stage the method collects all the necessary input data. Second phase is steady state analysis, where the N-1 principle is examined as well as the violation of thermal and voltage limits. As the greatest cross-border capacity in steady state is found, the dynamic analysis is run. Once a dynamically stable case is found, the capacity calculation is seen as completed. The developed method was tested in case study calculating the capacity for the AC-border between Finland and Sweden. In order to conduct the case study the input data was collected from the relevant TSOs, which included grid models which comprised the whole Nordic synchronous system. With these calculations the developed CNTC method was proven to give capacities close to the ones that the current NTC methodology gives for the border. In order to finalise the developed CNTC method into a capacity allocation and congestion management guideline compliant more work is needed. The topics for the further development include the implementation of the current capacity allocation methodologies and inclusion of remedial actions. The implementation of said additions require further testing in order to take the method to production use in the Nordic capacity calculation region