Battery Energy Storage System for Improving Primary Frequency Control with Increased Level of Photovoltaic Penetration

Power system inertia reduces with the increasing level of sustainable Photovoltaic (PV) generation. Hence, the power system will encounter several inevitable technical challenges, mainly in primary frequency control following a disturbance event. In this paper, a droop controlled Battery Energy Storage System (BESS) is proposed to reduce frequency oscillation by enhancing primary frequency controllability according to Australian National Energy Market (NEM) grid code and facilitate an increased level of PV penetration. Fossil-fueled based synchronous generator unit is replaced and the impact of PV penetration at various level is investigated. Moreover, battery state-of-charge recovery are also incorporated in this study. Simulation results with the droop-controlled BESS demonstrate that BESS effectively enhances the damping capability of the system in responding to primary frequency control and diminishes inertia related adverse impact with increased PV growth in the electric grid. In addition, it is observed that the system loading and generator control exhibit significant domination on primary frequency control of the system with the same level of PV penetration.