Grid-forming control is expected to play a pivotal role in the global transition to renewable energy, with the Virtual Synchronous Machine (VSM) approach emerging as a prominent solution. VSM control enables converter-connected renewable sources, such as wind turbines, to emulate the dynamic behavior of traditional synchronous generators (SGs) by providing synthetic inertia and damping—both critical for maintaining grid stability. The VSM loop extracts additional power during grid frequency disturbances, which leads to rotor deceleration and may push the turbine into the stall region. This introduces a trade-off, as entering stall limits the energy that can be extracted and impacts the turbine’s performance across its operational range—an aspect seldom addressed in current literature. This paper investigates the optimal tuning of VSM parameters across varying wind speeds, aiming to maximise energy contribution during frequency events while ensuring compliance with current UK grid code constraints.

The energy available from a wind turbine rotor increases significantly between wind speeds of 4 m/s and 8.5 m/s. Within this range, the primary constraint on VSM inertia tuning is the onset of rotor stall. Selecting a VSM gain that is too high results in excessive energy extraction during frequency events, causing rotor deceleration into the stall region, thereby violating the wind turbine energy limits. At higher wind speeds, however, the maximum permissible VSM gain progressively decreases. This is due to converter current limits, as the baseline power output prior to a frequency event is already high, leaving minimal headroom for additional power injection. This study hypothesis a gain-scheduled VSM approach designed to optimise inertial support across the full operating range of a wind turbine. While this strategy enhances performance during the inertial response timeframe, it also introduces drawbacks such as prolonged rotor recovery times and increased exposure to damaging oscillation frequencies. A 10MW wind turbine is modeled in MATLAB/Simulink to evaluate this approach. The results illustrate both the inherent limitations of inertial support from wind turbines and the potential benefits of adopting a more dynamic, adaptive control scheme.