Robust Guaranteed Cost Output Feedback Control for Real-Time Congestion Management

This article proposes an approach for line power flow regulation through a robust guaranteed cost output feedback controller to mitigate the congestion in power systems. Using the synchrophasor measurements from the lines, the controller regulates the power flows at a specified thermal limit or any other given security limit by re-dispatching the selected generators and Battery Energy Storage Systems (BESSs) in real time. Linear Matrix Inequality (LMI) conditions for robust controller design are given with the uncertain linearized models to satisfy finite
$ \mathcal {L}_{2}$
gain property of the system to worst-case external disturbances. Further, a min-max controller is designed to minimize the upper bound on the cost associated with the considered disturbance attenuation performance by solving an optimization problem. The efficacy and applicability of the proposed control scheme in regulating line power flows and mitigating congestion are demonstrated with extensive simulations on Kundur's 4-machine 2-area test system and a 16-machine 68-bus test system. It is shown that the designed controller can regulate line power flows within 40-60 s, which is fast enough to avoid overheating transmission lines, thereby improving the system's robustness.