ENERGY STORAGE SYSTEM FOR OPTIMAL OPERATION OF NEWLY INSTALLED BATTERY RACK AND CONTROL METHOD THEREFOR

Discussed is an energy storage system that may include a plurality of first battery racks; a central DC/DC converter connected to the plurality of first battery racks and configured to perform power conversion; a plurality of second battery racks; and a plurality of DC/DC converters connected to the plurality of second battery racks respectively and configured to perform power conversion. Here, the central DC/DC converter and the plurality of DC/DC converters are connected in parallel to a DC bus connected to at least one of a power conversion device (PCS) and a power generation device.