In this report, the study methods for sub-synchronous oscillations including large synchronous generators and VSCs are evaluated regarding the suitability for different systems. Also, converter design and control are described with focus on the contribution to sub-synchronous oscillations.
It is shown that there are screening methods suitable for finding risks for possible sub-synchronous oscillations. For evaluating the risk of oscillations between a certain synchronous generator and a VSC, there are frequency scanning methods that can be used together with time domain simulations.
