Distributed model predictive based secondary control for economic production and frequency regulation of microgrid

This work focuses on Distributed Secondary Control (DSC) technique, for frequency regulation and Economic Load Dispatch (ELD) of Microgrid (MG). The fluctuating nature and large quantity of Distributed Energy Resources (DER) in autonomous MG result in complex control requirements, demanding fast and robust response. The contemporary DSC schemes are mostly based on Distributed Averaging Integration technique, owing slow response. The paper proposes, Distributed Model Predictive based Secondary Control (DMPSC) which effectively comply with the control requirements of MG. DMPSC requires each DER-node to solve a local optimization problem with the cost function penalizing the deviation of states from their desired values and difference between the assumed and predicted values. The desired-states for nonlinear dynamics of DER-nodes, are based on local intermediate-optimum values, computed using local and neighbouring information. Equality based terminal constraints are introduced to ensure the stability, where each node is forced to reach the desired-state value at the end of prediction horizon. The terminal-consensus of the network affirms convergence of desired-states to a global optimal point of the network. The asymptotic stability of proposed control is proved by using the sum of local cost-functions as Lyapunov candidate function. Simulation results validate the effectiveness of the proposed control scheme.