Towards a reactive power oscillation damping controller for wind power plant based on full converter wind turbines

In this paper a power oscillation damping controller (POD) based on modulation of reactive power (ΔQ POD) is analyzed where the modular and distributed characteristics of the wind power plant (WPP) are considered. For a ΔQ POD it is essential that the phase of the modulated output is tightly controlled to achieve a positive damping contribution. It is investigated how a park level voltage, reactive power, and power factor control at different grid strengths interact with the ΔQ POD in terms of a resulting phase shift. A WPP is modular and distributed and a WPP ΔQ POD necessitate that each WT contributes to a collective response. This ability is shown with a 150 wind turbine (WT) WPP with all WTs represented, and it is demonstrated that the WPP contributes to the inter-area damping. The work is based on a nonlinear, dynamic model of the 3.6 MW Siemens Wind Power WT.