ENERGY STORAGE SYSTEM

An energy storage system according to an embodiment of the present disclosure includes a control container configured to include a battery system controller (BSC), a master controller configured to be connected to the BSC through a first communication line, and a bank battery management system (BBMS) configured to be connected to the BSC through a second communication line; and a battery container configured to include a slave controller configured to be connected to the master controller through the first communication line, and a rack battery management system (RBMS) connected to the BBMS through the second communication line and configured to monitor a state of a corresponding battery rack.