An Enhanced Primary Frequency Regulation Strategy for Thermal Power Plants-Energy Storage Systems Integrated System

The requirement for primary frequency regulation (PFR) capability of thermal power plants (TPPs) in power systems with larger penetration of renewable energy resources (RESs) is higher since the RESs contribute less to PFR compared with TPPs. To ensure the system frequency stability, this paper proposes to enhance the PFR capability of TPPs through integrating energy storage systems (ESSs) into them. By applying the PFR control strategy to the ESS, the fast response capability of the ESS is utilized, and the overall response speed of the power plant integrated with an ESS can be significantly improved. Furthermore, the state of charge (SOC) of the ESS is kept within the permissible range during the operation by adopting an energy recovery strategy to restore the released energy for PFR periodically. The effectiveness of the proposed control strategy is verified by simulation results.