ENERGY STORAGE SYSTEM AND INSULATION MONITORING METHOD FOR THE SAME

The present invention relates to an energy storage system (10) and an insulation monitoring method (S300) for the energy storage system (10). The energy storage system (10) includes a plurality of battery racks (100), each including a plurality of batteries and connected in parallel to one another, a power conversion device (110) connected to the plurality of battery racks (100) to convert power, a main switch (130) configured to turn on and off a current flow between the plurality of battery racks (100) and the power conversion device (110), a first insulation monitoring device (140) and a second insulation monitoring device (142) each connected to respective terminals of the main switch (130), and a controller (120) configured to control operations of the main switch (130), the first insulation monitoring device (140), and the second insulation monitoring device (142). The first insulation monitoring device (140) monitors insulation information regarding the power conversion device (110), and the second insulation monitoring device (142) monitors insulation information regarding the plurality of battery racks (100).