Providing system level frequency support from wind across the full operating range

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Conventional synchronous generation provides inherent frequency support to power networks via thephysical inertial properties of the machines. As the number of these synchronous generators on the networkdecreases, and converter-interfaced renewable generation increases, this frequency support must now beprovided from other sources. The use of wind turbines to provide frequency support at the inertial timescale(roughly 5ms - 2s) has been established as a feasible proposition for some time and in multiple studies.However, several issues remain for the use of wind power to provide this frequency support:>Most studies of inertial support from WTs are based on operation at full power. However, grid codesrequire inertia provision to be guaranteed at all operating points. How can inertia provision beextended to be provided at lower wind speeds?>What is the best way of quantifying inertia provision given the variation across operating conditions?>What is the optimum strategy for inertia provision across the maximum operating range e.g.,curtailment versus temporary over-rating?>How do grid forming algorithms perform in terms of inertia provision in a network with high converterpenetration and how can it best be operated/tuned to provide frequency support?>To what extent can WTs using Grid Forming control schemes be used to contribute to droop supportover the 2s to a few minutes timescale? What is the cost in terms of lost energy production prior toan event?>Inertia support at WT level vs farm level - which is the best control strategy to maximise frequencysupport and minimise negative impacts on individual WTs?This project should review the current control strategies, performance and limitations in the literature forfrequency support from WTs. A range of time and frequency domain modelling techniques should be used toimplement control strategies for frequency support, assess performance across the operating point range andsuggest improvements for providing inertia support at low wind speeds. The impact on WT energy productionand lifetime health and the limitations of WTs for frequency support should also be analysed. The addition ofenergy storage to improve performance may also be considered.