Analysis and Experimental Implementation of Grid Frequency Regulation Using Behind-the-Meter Batteries Compensating for Fast Load Demand Variations

This paper proposes a new grid frequency regulation (GFR) scheme using behind-the-meter battery energy storage systems (BESSs). The fast dynamic responses of the electrical BESSs enable buildings to compensate for the high-frequency components of load demand variations, through direct load control (DLC). An electrical system in a building, along with its building-level and device-level controllers, is considered to address the difficulties in the application of DLC, especially in communicating with several small-scale BESSs. A small-signal analysis is carried out using the aggregated responses of the generators and the DLC-enabled buildings to investigate the proposed GFR scheme, particularly with respect to the feedback controllers for the buildings. Simulation studies are performed using a test grid for various penetrations of the DLC-enabled buildings, and the test grid is implemented using a laboratory-scale microgrid. The proposed GFR is effective in reducing the frequency deviations and required reserve capacity of the generators, which is achieved by making small variations in the state-of-charge of the behind-the-meter battery.