Re-thinking Short-Circuit Current Contribution from Type IV Wind Turbines: A Perspective into How Standardization Can Be Improved

Discussions on short-circuit current (SCC) contributions from type IV wind turbines and other inverter-based resources (IBRs) are becoming more relevant and common as power systems are more and more penetrated by renewable energy sources. Several works have brought attention to the fact that IBRs do not behave entirely as a fixed current source during faults as some standards have proposed so far. In contrast, they behave as voltage- and grid-code-dependent current sources in the fault steady-state and can be highly non-linear during the fault transient stage, which increases the complexity of estimating SCC contributions. This paper presents a new perspective on how the improvement of standards and guidelines can help establish effective and intellectual property-independent approaches to estimate SCC contributions from type IV generators. To base the discussion, results from field-validated EMT models of a large-scale offshore grid-following wind turbine are shown in simulations that demonstrate the need for standardized procedures.