Open-Source Electromagnetic Transient White-Box Model of Converters for Renewable Energy Grid-Connected System Analysis

• • Full-order small-signal state-space equations derived for GFL/GFM converters, capturing complete circuit and control dynamics; this eliminates the reduced-order approximations common in stability studies, enabling one-to-one correspondence between theoretical and simulation models, which is critical for mechanism research and parameter tuning. • • Modular white-box model implemented on CloudPSS with per-unit and single-machine multiplier equivalence; the model supports different voltage levels and rated capacities, allowing the same model to represent various devices (wind, PV, storage, SVG) by adjusting module combinations and parameters, thus reducing model development time and enhancing reusability. • • Validation against time-domain EMT simulations confirms accurate small/large disturbance responses; sensitivity analysis reveals that short-circuit ratio, reactance-resistance ratio, and double-loop PI parameters significantly affect stability margins, providing quantitative guidance for control parameter design and grid strength assessment. • • The model is integrated into a hybrid AC/DC grid standard test system, demonstrating high simulation efficiency; the open-source release on CloudPSS facilitates community-driven standardization of EMT models for renewable energy converters, addressing the lack of standardized white-box models in the industry.