A modeling and simulation of optimized interconnection between DC microgrids with novel strategies of voltage, power and control

摘要

The interconnection between DC microgrids has been studied through the modeling and simulation of two DC microgrids and utility network with independent connection to each microgrid. Each microgrid has generation sources, storage source, electrical charges, two points of common coupling (one with the utility network and other with the neighboring microgrid) and a central controller. By performing the simulations and searching for new ways in which the interconnection can be made, the following contributions are reached: (a) although a nominal voltage is present on the DC microgrid bus, it becomes necessary to have three mini-voltage scales (one for the micro-sources, another for the storage sources and a third for AC/DC converter output that connects the utility supply and DC microgrid bus); (b) the power to avoid being heavily dependent on random variables requires temporary storage at the generation sources and that electrical loads define a very stable demand and clearance for certain period of time (of a few minutes), said period would be a new time scale of microgrid operation; (c) the cost associated with generation and storage sources must be optimized for the microgrids operation on the new unit of measurement and for which linear programming techniques have been used, and (d) it representing new coordination actions for tertiary control among central controllers of the microgrids. The new strategies of control, voltage and power will serve to propose and study new designs of: topologies of the electrical network, interconnection devices between microredes and other topics.