A Distributed Generation Control Architecture for Islanded AC Microgrids

In this paper, we propose a distributed architecture for generation control in islanded ac microgrids with both synchronous generators and inverter-interfaced power supplies. Although they are smaller and have lower ratings, the generation control objectives for an islanded microgrid are similar to those in large power systems, e.g., bulk power transmission networks; specifically, without violating limits on generator power output, frequency must be regulated and generation costs should be minimized. However, in large power systems, the implementation of the generation control functions is centralized, i.e., there is a computer that resides in a centralized location, e.g., a control center, with measurements and control signals telemetered between the generating units and the centrally located computer. The architecture for generation control that we propose in this paper does not rely on such a centrally located computer. Instead, the implementation of the control functions is distributed and relies on iterative algorithms that combine local measurements and certain information acquired from neighboring generating units with local, low-complexity computations. We provide analytical and experimental results that verify the effectiveness of the proposed architecture for generation control in islanded microgrids, and illustrate the performance of the aforementioned distributed algorithms under a variety of scenarios.