ENERGY STORAGE SYSTEM AND METHOD FOR CONTROLLING GROUNDING STRUCTURE OF ENERGY STORAGE SYSTEM

An energy storage system, including a photovoltaic (PV) system and a battery system and connected with a power grid, may comprise a power conversion system (PCS) connected with the power grid and selectively connected to at least one of the photovoltaic system and the battery system; a first switch selectively connecting the photovoltaic system and a direct current (DC) link of the power conversion system; a second switch selectively connecting the battery system and a DC link of the power conversion system; and a controller for controlling a ground structure of at least one of the photovoltaic system, the battery system, and the power conversion system by controlling the first switch and the second switch based on a state of the photovoltaic system and a state of the battery system.