Identifying Grid-Connected Converters Behaviour Based On Current and Voltage Source Characteristic

The integration of renewable generation into the existing power grid heavily relies on converter-based technologies. The increasing penetration of Inverter-Based renewable sources (IBRs) in the network impacts system stability, necessitating the development of new grid codes and industrial practices. IBRs are typically classified into Grid-Forming (GFM) and Grid-Following (GFL) control approaches, with grid codes approximating these controllers’ behaviours as voltage and current sources, respectively. Furthermore, identifying the control type of Electromagnetic Transients (EMT) vendor models is challenging using frequency-domain analysis. This paper proposes a method to assess converter characteristics by comparing the ideal voltage and current source behaviours using the time-domain response of converters. The results provide a clear methodology for characterizing GFM and GFL converters using time-domain signals alone, employing a fixed 5ms window to analyse transient behaviour.