Method for controlling power grid frequency of multiple energy storage systems, and system therefor

A power grid frequency control system for controlling a power grid frequency for multiple energy storage systems using a hierarchical control structure, comprising:

• a plurality of energy storage systems (ESSs);
• a local management system (LMS) configured to manage at least one of the energy storage systems on a local basis;
• an energy storage system controller (ESS controller) configured to generally control the local management system by determining a state of the local management system, estimating an output value of at least one of the energy storage systems belonging to the local management system, and transmitting the estimated output value to each energy storage system;
• and
• a power management system (PMS) configured to generally manage overall systems including the plurality of energy storage systems, the local management system, and the energy storage system controller, determine states of the overall systems to allow a user to participate in a power grid frequency control market by making a contract with a system operator, control an output value of the local management system, and regulate control parameters for controlling the output value,
• wherein, when a plurality of the energy storage system controllers are provided, the power management system determines control parameters for controlling frequencies of the energy storage system controllers, sets a participating energy ratio for a frequency response and frequency regulation control depending on a frequency state on the basis of the determined control parameters, and performs the frequency response and frequency regulation control depending on the set participating energy ratio.