Autonomous Frequency Regulation of a Grid-Following Converter Powered by Battery Energy Storage System

This paper deals with an Autonomous Frequency Regulation (AFR) of a grid-following (GFL) converter powered by a Battery Energy Storage System(BESS). It deals with the frequency stabilization function of a small-sized BESS system that will be widely used along with the spread of electric vehicles and eco-friendly housing. As requirements of AFR, it should be able to actively respond to the frequency deviation using the measured voltage at a PCC (Point of Common Coupling). Due to battery capacity limitation, the variation of energy in a BESS for AFR should be limited to a level that does not affect the original installation purpose (e.g., load transfer, uninterruptible power supply, etc.). So in this paper, a new AFR method has been proposed, which uses a PI-based selective frequency damping and achieves cooperative frequency support while obeying the Electric Power System (EPS)’ frequency control scheme. As a verification, the effect of the proposed AFR algorithm mounted on the GFL converter is simulated in a modified IEEE-14 bus system having multiple random loads and multiple distributed ESSs.