Optimal DC microgrid power apportionment and closed loop storage control to mitigate source and load transients

This paper considers the optimal management of an N source, DC microgrid with time-varying sources and loads. Optimality is defined as minimizing the amount of power lost through the boost converters that connect the N sources to the DC bus. The optimal power apportionment strategy is part of an overall grid management system that also includes control laws that manage bus voltage and boost currents using distributed energy storage. The performance of an optimal power apportionment strategy is compared to an existing, alternate approach using a three source simulation for both source and load step transients. The optimal power apportionment strategy is shown to use less power while maintaining bus voltage in the presence of both load and source transients. Since the optimal solution requires information exchange between all the sources, there is an opportunity for malicious attack. The ability of the strategy to maintain the desired bus voltage in the presence of an uncommunicated source failure is also presented.