Quantification Method of the PFR Substitution Effect by BESS for Frequency Regulation considering the Increased Penetration of Renewable Energy Sources

In the Korean power system, the Primary Frequency Response (PFR) is provided by the Battery Energy Storage System (BESS) as well as the generator governor for arresting the frequency excursion caused by an unexpected disconnection of generation units. However, given that the frequency response performance of BESS is superior to that of the existing governor response, it is important to configure the required amount of PFR with generators and BESS for the stable and efficient operation of the power system especially when the penetration level of Renewable Energy Sources (RES) is highly increased. Therefore, in this paper, the PFR contribution effect by BESS was quantified by determining the substitutable governor response quantity considering the penetration of RES, when the BESS provides the PFR using the control algorithm implemented in the operating site. Further, the quantification of the PFR substitution effect by BESS using the proposed method is performed in the Korean power system under renewable penetration scenarios. The results prove the validity of the proposed method and show that the PFR substitution effect by BESS increases as the penetration of RES increases.