Application of Frequency Regulation Control on the 4MW/8MWh Battery Energy Storage System (BESS) in Jeju Island, Republic of Korea

Energy Storage Systems (ESS) have an impressive track record for providing stability and efficient power management in power system. With recent technological advancements and the decline in costs, the use of battery for ESS is gradually becoming popular in the power industry. In particular, Lithium-ion Battery (LiB) is being used in various power grids around the world. In Jocheon, Jeju Island, Republic of Korea, operation and control of grid-connected Battery Energy Storage System (BESS) of 4MW/8MWh capacity has been in demonstration phase since 2013. Several simulation tests were already performed for peak shaving, renewable energy output smoothing, and most recently, frequency regulation control. On-site tests are continuously performed for frequency regulation. In previous tests, control algorithm was coded, modified and tested to load into controller and communication system, and human-machine interface was developed. The BESS Energy storage was connected to grid for frequency regulation using both simulated and actual frequency variations. The most recent results are presented in this paper showing BESS frequency regulation with continuous operation duration for three days. It was also observed in the results that BESS frequency regulation has faster response, less costs and less capacity of energy storage systems which cover for frequency regulation of power plants. Time reduction and time-delay elements are also investigated.