Hierarchical Two-Tier Optimization Framework For The Optimal Operation Of A Network Of Hybrid Renewable Energy Systems

Hybrid renewable energy system (HRES) is a nexus of several renewable energy systems that concertedly overcomes the limitations of individual systems operating in isolation. This concept of HRES is extended in this study by considering the network of several such HRESs which further improves the flexibility in overcoming the individual limitations. How-ever, operating such a network of HRESs involves complex decision-making and requires efficient optimization. In this study, a novel hierarchical two-tier optimization methodology for a network of HRESs is proposed when they trade power with each other and with the macro grid. In the proposed methodology, the operational optimization of each HRES is car-ried out by minimizing the operating cost of various sub-units in the first layer. In the second layer, three cooperative optimization strategies inspired from concepts of double-auction e-marketing are applied when HRESs are assumed to operate under the grand coalition. These three cooperative strategies try to achieve the following objectives (i) minimization of power loss during local trade, (ii) maximization of total market gain, and (iii) simultane-ous power loss minimization and total market gain maximization, respectively. Simulation results depict that the cooperative optimization approach yields a reduction in power loss up to 7 % and improvement in market utility up to 29% relative to a scenario when they operate non-cooperatively. (c) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.