Analysis of hardware optimisation and curtailment on maximum inertial response from grid-forming wind turbines

Converter-interfaced wind turbines inherently lack the inertial response of synchronous generators, reducing frequency stability in low-inertia power systems. While virtual synchronous machine control enables wind turbines to emulate inertial behaviour, the practical limits of inertia provision and the dominant mechanisms constraining performance remain poorly understood. This paper quantifies the maximum achievable inertia from a 10MW grid-forming wind turbine across its operating range and identifies the limiting factors governing inertial support. A linear bisection optimisation framework determines the maximum permissible VSM inertia constant at each wind speed while satisfying grid code requirements and wind turbine operating constraints. The methodology evaluates the influence of DC-link capacitance, converter current rating and turbine curtailment on achievable inertial response. The results show that the dominant limiting mechanism varies with operating point, with DC-link voltage and modulation constraints restricting inertia at lower wind speeds, while converter current limits dominate at higher wind speeds. Increasing DC-link capacitance improves inertial capability, although diminishing returns are observed beyond 0.03F. Converter uprating from 1.3pu to 1.4pu increases achievable inertia by over 31%, while curtailing to a 0.9pu power limit increases available inertial energy by over 59%. A techno-economic assessment demonstrates that converter uprating provides a lower lifetime cost per unit of additional inertia than curtailment, although the latter can be implemented without hardware modification. The findings provide new insight into the practical limits of inertia provision from grid-forming wind turbines and highlight the importance of jointly considering control design, hardware sizing and economic incentives when deploying wind-based frequency support.