Passivity-Based Design of Sliding Modes for Optimal Load Frequency Control

This paper proposes a distributed sliding mode (SM) control strategy for optimal load frequency control (OLFC) in power networks, where besides frequency regulation, minimization of generation costs is also achieved (economic dispatch). We study a nonlinear power network of interconnected (equivalent) generators, including voltage and second-order turbine-governor dynamics. The turbine-governor dynamics suggest the design of a sliding manifold such that the turbine-governor system enjoys a suitable passivity property, once the sliding manifold is attained. This paper offers a new perspective on OLFC by means of SM control, and in comparison with the existing literature, we relax required dissipation conditions on the generation side and assumptions on the system parameters

Sliding Mode Observer-Based Finite Time Control Scheme for Frequency Regulation and Economic Dispatch in Power Grids

This is the author accepted manuscript. The final version is available from Institute of Electrical and Electronics Engineers via the DOI in this record.In this brief, a novel sliding mode (SM) observer-based scheme is proposed to achieve frequency regulation and economic dispatch (ED) in power grids composed of interconnection of generators and load buses. The ED problem is addressed in two steps. Assuming only the voltage phase angles are measured, in the first step a network of heterogeneous SM observers, suitably interconnected in a distributed fashion, is created to estimate both frequency deviations and unknown power levels associated with each bus. In the second step, the observer scheme is coupled with an SM control strategy which is able to reach the optimal value of the control input in each generator bus in finite time. The scheme is assessed via the IEEE 39 bus benchmark, and a comparison with existing control methods is provided

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