In summary, Battery Energy Storage Systems can typically detect and respond to frequency changes within milliseconds, making them highly effective for fast frequency response and grid stability services in today's evolving power systems. This rapid reaction capability, often referred to as Fast Frequency Response (FFR), enables BESS to either discharge or charge almost instantaneously upon detecting a. . In particular, energy storage participating in grid frequency modulation requires frequent switching of its charge and discharge state, which is more likely to accelerate battery aging, shorten its life cycle, and increase the cost of single frequency modulation. To this end, this paper proposes a. . uation of power system becomes more and more serious. The frequency modulation of thermal power unit has disadvantag s such as long response time and slow climbing speed. Battery energy ing the wind farm power output disturbing frequently. When the flywheel energy storag ondary Frequency. . FFR is the fastest frequency control service, typically activated within 1 second or less when system frequency experiences a sharp dip or rise. This service is crucial in the early moments of a disturbance—before traditional generators can ramp up. The application of energy storage system to power system, whether to deal with load. .