Apparatus and method for ess to supplement grid power

An energy storage system (ESS) management method comprising:

• in a battery charging management system including an energy storage system (ESS),
• a step of confirming a first electric energy used in a power grid, a second electric energy required for a charger used in electric vehicle charging, and a third electric energy used in a load of other areas connected to the power grid;
• and
• selectively performing a charging/discharging mode for supplement the power of the power grid or a diagnosis mode of sensing a diagnosis necessity and giving a warning according to a confirmation result of the electric energies.

An energy storage system (ESS) management system comprising:

• in a battery management system (BMS) connected to a power grid,
• a power conversion unit receiving and converting power from the power grid;
• an energy storage system (ESS) connected to the power grid and the power conversion unit;
• and
• a sensor network implemented to perform power flow judgment and management of an entire system in which the energy storage system (ESS) is installed.