Abstract:
The continuous increase in the proportion of new energy grid connection has reduced the inertia of the power system, leading to a decrease in system frequency regulation capability. In response to this issue, research on the participation of energy storage in frequency regulation has been carried out. The participation of energy storage in frequency regulation is influenced by factors such as unit quantity, state of charge(SOC), and charge-discharge strategy. A coordinated control strategy for energy storage units considering frequency deadband is proposed. Energy storage units are grouped based on SOC consistency, and different groups independently execute droop control or virtual inertia control to simplify output control commands. Control command switching is based on system frequency deviation or frequency rate of change, with frequency deviation and rate-of-change deadbands set to reduce disturbances causing frequent charging and discharging of energy storage systems. Simulation verification using Matlab/Simulink shows that the proposed control strategy is simple to implement, can quickly respond to frequency regulation requirements, and can ensure the lifespan of energy storage batteries.