Open-Source Electromagnetic Transient White-Box Model of Converters for Renewable Energy Grid-Connected System Analysis
The large-scale integration of power electronic converters in high-proportion renewable energy systems imposes stringent requirements on the accuracy and extensibility of grid-following (GFL) and grid-forming (GFM) converter models. This paper derives a theoretical model of GFL/GFM grid-connected converters that accounts for complete circuit and control dynamics, and constructs an open-source white-box converter model on the CloudPSS electromagnetic transient (EMT) simulation platform. The model adopts per-unit and structural design for electrical topology, control loops, and multiplier equivalence, enabling simulation of converters with various voltage levels and rated capacities. Theoretical calculations and simulation results demonstrate that the model exhibits accurate disturbance response, flexible parameter configuration, strong extensibility, and high simulation efficiency. The model provides a foundation for constructing a standardized EMT model library for renewable energy converters. The full-order small-signal state-space equations are provided, and the conversion between per-unit time and named time is derived. Case studies validate small/large disturbance responses, parameter sensitivity (short-circuit ratio, reactance-resistance ratio, PI parameters), and simulation efficiency in a hybrid AC/DC grid standard test system. The model and test cases are publicly available on the CloudPSS official website.