Experimental Study of Battery Energy Storage Systems Participating in Grid Frequency Regulation

Battery energy storage systems (BESS) have been regarded as a promising source for grid frequency regulation (GFR) through direct load control (DLC). This paper proposes a real-time GFR scheme using BESS that can respond to local and central DLC signals. Specifically, using the fast response time, the BESS compensate for high-frequency components of grid frequency deviation, while conventional generation units are controlled to mitigate low-frequency variations in load demand. To evaluate the contribution of DLC-enabled PEVs to GFR, a laboratory-scale isolated microgrid was implemented using a real inverter-interfaced battery pack. The experimental studies demonstrate that BESS can be effectively exploited as a DLC-enabled load in the proposed GFR, resulting in small variation of state-of-charge (SOC).