Co-simulation model for safety and reliability of electric systems in a flexible environment of NPP (COSI)

This interim report summarises the progress achieved thus far in the COSI project (the time of writing is February, 2021). Essentially, a co-simulation model has been developed that interfaces a Nuclear Power Plant (NPP) with its internal electrical network, which has already producing some interesting results, some of which have already been reported in D.1.1 and published. A scaled down first version of the Finnish transmission network has been modelled that has interfaced successfully with a simplified version of the internal electrical network, and some preliminary simulation results have been attained. The main challenges are implementing changes in the Apros modelling of the NPP, including endowing it with a time resolution commensurate with that required to model faults in the power system and getting the full co-simulation model running, i.e., the Apros modelling of the NPP and the Matlab Simscape models of the full internal NPP electrical network and a sufficient model of the external Finnish transmission network. The authors are mindful of the computational burden and lack of efficacy in overdeveloping the transmission model. The main goal of the third year of the project is to improve the existing model to be fit for purpose and utilize it to investigate events in the internal network and transmission network that are most likely to adversely impact the NPP. To this end a simulation matrix is being developed so that we can most efficiently harness the resources we have available in the third year of this project. Preliminary simulations produced in report D.2.2 at the end of 2021 show
promise, although it would be unwise to over-interpret these preliminary results