This project seeks to extend the InitialDynamic Model of Continental Europe (IDMCE) by including the dynamics of the Nordic transmission system and their interaction with the IDMCE through thecorresponding HVDC interconnection. The expanded system will be implemented in the OPALRT real-time simulator setup (based on OP5600) at SINTEF for potentialtransient stability studies considering HIL techniques. The main expectedoutcome is the availability of an extended power system simulation model toexplore offline and in real time the mutual interaction and supportingstrategies between the central Europe (CE) and Nordic transmission grids for anoverall system performance improvement.