Impact of grid-forming wind turbine model order reduction on interaction studies with inter-area oscillations

The energy transition towards carbon-neutrality is rapidly changing power systems as more wind energy is increasingly being integrated. As the power electronics interfaced energy resources share increases, stability concerns arise due to the devices’ distinct behavior with respect to traditional equipment. In this context, grid forming converter control (GFM) is highlighted as a system stabilizing solution. Especially, wind turbines (WT) with GFM functionalities are a potential technology to support system stability while providing renewable energy. However, the impact of GFM WT on traditional power stability phenomena related to synchronous generators (SG) requires further investigation. This paper conducts an analysis of the impact of GFM-WT modeling fidelity for conducting power system studies efficiently. In addition, we focus on inter-area modes and their interplay with low frequency turbine modes linked to the drive-train and GFM control. The validity and effectiveness of the proposed reduced-order models for small-signal stability analysis is demonstrated by frequency response comparison and an investigation of the model structure from a state-space perspective. Lastly, the impact of different GFM-WT drive-train and control parameters on inter-area oscillations is studied for a modified two-area power system. All the results discussed in this paper are validated through electromagnetic transient (EMT) simulation.