A stochastic operation optimization framework of micro-grid to improve economics, reliability, and voltage security considering flexi-renewable energy hubs

In this paper, the eco-operation of the microgrid is investigated, with an emphasis on the security of voltage and network reliability by means of flexible renewable energy hubs. A multi-objective energy scheduling approach for microgrids featuring flexible renewable hubs, as well as the modeling of electric vehicle flexibility and the operation of bio-waste systems integrated with a combined power and heat system is presented. The scheme is a four-objective optimization model aimed at minimizing operating costs, energy losses, and unmet energy, while maximizing voltage security in the grid. The constraints include the AC optimal dispatch model, the security and reliability limits of the microgrid, the operation model of resources and storage functioning as an energy hub, and the flexibility limitations of the hub. The weighted sum method is utilized for obtaining single-objective optimization of the scheme, while the fuzzy decision-making methodology is utilized for extracting the compromise solution. In order to accurately assess the flexibility and reliability of a microgrid, the SBSO technique is employed to model the uncertainties associated with renewable resources, load, energy prices, electric vehicles, and network equipment availability. According to the results of the research, the optimal performance of flexible-renewable hubs has been demonstrated to enhance economic, operational, reliability, and voltage security indicators in microgrids. The numerical results indicate that these indicators improve to 40.9%, 33.5%-64.5%, 90.8%, and 20.2%, respectively, when compared to load flow study results.