A Coordinated Control Scheme to Integrate Flywheels Energy Storage Systems in AGC

This paper proposes a new control scheme to coordinate the operation of Flywheels Energy Storage Systems (FESS) within the Automatic Generation Control (AGC). The proposed control classifies both charging and discharging modes into two zones of operation: normal and critical. The critical zones occur when the FESS is close to be fully charged or discharged. The proposed control provides a significant step towards adopting distributed control for AGC applications, where it gives the FESS self-authority in determining its output power under critical state-of-charge (SoC). Further, the proposed control guarantees that not only the SoC of FESS is maintained within the limits, but also the post-disturbance oscillations of slow conventional generators are minimized. This would in turn reduces the maintenance cost and increases the lifetime of these conventional generation units. PSCAD simulations have been conducted to validate the effectiveness of the proposed control strategy on the New England IEEE 39 bus test system.