Performance assessment of grid-forming converters frequency support during disturbances in active distribution networks

Abstract

The use of Grid Forming Methodology (GFM) in grid-connected systems represents an innovative approach to improving the stability and flexibility of power grids. This article will elucidate the methodology, assess its frequency-related performance and stability under disturbances like load changes, and emphasize the importance of the droop control coefficient. Based on the frequency derivative, which gives more information compared to the frequency, we used the rate of change of frequency (RoCoF) instead of frequency as an indicator to compare different scenarios and highlight differences in performance after changes in loads. The RoCoF factor and the critical clearing time are determined as metrics to compare system performance and stability. To determine the gain of the controller, the Result adaptive PID controller is performed, and its performance is compared to the classical PID controller based on the trial/error method. In the rest of the article, we relied on controlling the RAPID controller, which gave the best performance. Finally, the effectiveness and accuracy of the method were verified through simulation.