@article{tu_du_yu_meena_lu_lukic_2023, title={Distributed Economic Dispatch for Microgrids Tracking Ramp Power Commands}, volume={14}, ISSN={["1949-3061"]}, url={https://doi.org/10.1109/TSG.2022.3189534}, DOI={10.1109/TSG.2022.3189534}, abstractNote={When in grid-connected mode of operation, distributed generators (DGs) within the microgrid (MG) can coordinate to act as a single entity to provide services to the bulk grid. The DGs can coordinate their power production to minimize the total operating cost, which is known as the distributed economic dispatch. Various methods have been proposed to solve the MG economic dispatch problem (EDP) in a distributed fashion, under the assumption that DGs’ power output, in aggregate, follows a constant or slowly varying power command. However, when the MG is providing frequency regulation service, or the internal load is highly dynamic, the MG EDP becomes dynamic, and the state-of-the-art distributed approaches cannot guarantee optimality. In this paper, we propose a distributed economic dispatch algorithm for MGs providing frequency regulation service, as an example of a dispatch profile with ramp commands. A consensus protocol guaranteeing zero steady-state error for ramp inputs is integrated into the EDP to find the optimal solution in a distributed way. With the proposed algorithm, the MG is able to tightly follow a time-varying regulation signal while maintaining an optimal economic dispatch for all the DGs within. We validate the proposed method using regulation signals from PJM and demonstrate the algorithm on a hardware-in-the-loop testbed.}, number={1}, journal={IEEE TRANSACTIONS ON SMART GRID}, author={Tu, Hao and Du, Yuhua and Yu, Hui and Meena, Shweta and Lu, Xiaonan and Lukic, Srdjan}, year={2023}, month={Jan}, pages={94–111} }
 @article{meena_tu_yu_lukic_2022, title={Economic Dispatch in Microgrids using Relaxed Mixed Integer Linear Programming}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE50734.2022.9947665}, abstractNote={Economic dispatch (ED) in a microgrid is vital to supply the load demand with a minimum cost of operation. Considering the large number of discrete variables involved in ED formulation, it is common in practice to use Mixed Integer Linear Programming (MILP) for solving the optimization problem. However, as the problem size increases, the convergence time of MILP can exponentially increase owing to the NP-hard nature of the algorithm. This paper reviews the state of the art ED formulations and proposes an equally optimal and time-efficient method, Relaxed Mixed Integer Linear Programming (RMILP) for executing the day-ahead ED in a microgrid with large problem size. Using the proposed algorithm, ED problems with smaller timesteps can be solved in a reasonable time for large systems. In addition, the load is modeled as a discrete variable which is more realistic from the perspective of load shedding and often ignored in ED formulations in the literature. We apply the proposed approach to the Banshee distribution feeders and show its advantages over conventional methods.}, journal={2022 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Meena, Shweta and Tu, Hao and Yu, Hui and Lukic, Srdjan}, year={2022} }