  Due to the increased deployment of renewable energy sources and intelligent
components the electric power system will exhibit a large degree of
heterogeneity, which requires inclusive and multi-disciplinary system
assessment. The concept of co-simulation is a very attractive option to achieve
this; each domain-specific subsystem can be addressed via its own specialized
simulation tool. The applicability, however, depends on aspects like
standardised interfaces, automated case creation, initialisation, and the
scalability of the co-simulation itself. This work deals with the inclusion of
the Functional Mock-up Interface for co-simulation into the DIgSILENT
PowerFactory simulator, and tests its accuracy, implementation, and scalability
for the grid connection study of a wind power plant. The coupling between the
RMS mode of PowerFactory and MATLAB/Simulink in a standardised manner is shown.
This approach allows a straightforward inclusion of black-boxed modelling, is
easily scalable in size, quantity, and component type.
