Stacked benefit applications of energy storage systems in distribution circuits

This paper develops real and reactive power control methods to demonstrate the viability of deploying energy storage (ES) in simultaneously providing multiple applications, i.e., voltage management and ancillary service in the form of frequency regulation. The location and size of ES for stacked benefit applications are identified. To evaluate the benefits of ES, several case studies are simulated using a distribution system simulator. The simulation results show that ES can successfully provide voltage management and frequency regulation services to the distribution circuit. Voltage regulation can be achieved by controlling the reactive power generated or absorbed by the ES inverter. In this control mode, ES can successfully mitigate the voltage variation concerns due to the variability of both PV generation and the frequency regulation schedule. Frequency regulation service, on the other hand, can be achieved by using real power control of ES. In this control mode, ES charges and discharges in accordance with the frequency regulation schedule. By simultaneously controlling both real and reactive power, ES can provide multiple benefits termed as stacked benefits for the feeder.