Microgrid using parallel processing uninterruptible power supply

The effectiveness of two patterns for operating a self-sufficient (i.e., smart) microgrid was investigated. One pattern minimizes connection time to the utility power grid, and the other minimizes the peak load drawn from the utility power grid and maximizes battery life. Field testing of a demonstration system showed that it can switch between modes (island, charge, and backup) and continue to supply power to the load without interruption. Simulation and field testing showed that the prioritize island mode pattern is advantageous in terms of minimizing the time spent in charge mode while the prioritize steady use of utility power pattern is advantageous in terms of minimizing the peak utility power received and the battery state of charge range.