Concurrent distributed control of all power components in an autonomous microgrid

DC and AC microgrids have been proposed for different applications using new technologies in power electronics and new energy sources. The power sources in a microgrid must be controlled in coordination with each other in order to meet the operating criteria of the microgrid as a whole. Droop control of power sources is a known solution for distributed and coordinated control of converters to share active and reactive power in a microgrid. In this paper, the droop control method is extended for harmonic and unbalance power along with balanced active and reactive sharing. Each component of power can be dedicated to various power sources in any percentage, which enables operation optimization of the microgrid. An upper layer controller which uses a low speed communication link sets droop parameters of local controllers. This control layer is in charge of real time optimization of micro grid as well as load bus voltage quality improvement.