Stability analysis for large power system interconnections in Europe

A worldwide trend in the development of power systems is to build interconnections with the goal to achieve economical benefits. The interconnections are mostly realized by synchronous links where such solutions are technically feasible and economically justified (AC solution). In cases where the synchronous interconnection is technically not feasible, an HVDC coupling station or HVDC log distance transmission (DC solution) can be used. Finally, the DC solution can also be applied in combination with a synchronous interconnection in order to support the operation of the interconnected systems and thus makes the synchronous AC link more reliable (hybrid solution). The evaluation of the best solution for large system interconnections requires detailed system models for stability analysis. In the paper, examples of very large power system simulations are shown. Simulation results are given for DC and AC interconnections. There are practically no limits for the size of the systems, which can be handled by modern computer simulation tools, e.g. the described advanced simulation program. Finally, the challenges of further system interconnections in Europe are considered on the base of the existing experience in stability analysis.