A Comparison between RMS and EMT Grid-Forming Implementations in MATLAB/Simscape for Smart Grids Dynamics

The article presents a comparison between phasor RMS and EMT models for grid-forming converters. The specific aspects related to the implementation in Simscape Electrical of MATLAB/Simulink are discussed for both RMS and EMT time-domains. The comparison between the different implementations is performed with the simulation of two widely studied grid-forming schemes, the virtual synchronous machine and the power-synchronization control. The simulation-based comparison examines transient phenomena with different characteristics and time scales, including frequency transients, phase jumps and short-circuit events. Specific indications regarding limitations and suitability of grid-forming models in the RMS and the EMT time-domains are provided, sharing the experience in implementing dynamic models of grid-forming converters.