An Integrated Control Strategy for Energy Storage Participating in Primary Frequency Regulation Considering State of Charge Constraint

In view of the fact that battery energy storage possesses such advantages as fast response speed, high control accuracy and flexible capacity configuration, it gains wide attention recently in power grid frequency regulation. However, traditional control method is easy to make over-charge or discharge of the battery, so the power grid operation and battery use are affected. In allusion to this situation, considering the state of charge (abbr. SOC) constraint an integrated control strategy with the participation of energy storage for power grid primary frequency regulation is proposed. Firstly, an automatic generation control (abbr. AGC) model with energy storage battery participating in power grid primary frequency regulation was constructed, and a scheme to conduct the configure the energy storage capacity according to SOC constraint of the battery was proposed. Secondly, by means of the feature analysis on virtual inertial control for energy storage and virtual droop control the distribution proportion coefficient was designed according to the dynamic change of power grid frequency deviation, thus the smooth change of the participation degree of the two ways was realized. Thirdly, taking the parameter adaptive regulation suited to the SOC condition of the battery as the objective, the adjustment of charging and discharging control coefficients of energy storage was carried out to improve the frequency regulation performance and the change feature of SOC of the battery. Finally, by means of the simulation comparison of various methods the feasibility and effectiveness of the proposed method are verified.