Selective compensation of reactive, unbalance, and distortion power in smart grids by synergistic control of distributed switching power interfaces

Smart grids feature distributed energy resources interfaced to the grid by means of switching power converters. Synergistic control of these units can considerably increase the distribution efficiency and power quality by limiting the unbalance, reactive, and harmonic currents flowing through distribution lines. This can be achieved by a distributed control and communication architecture which implements suitable control strategies. This paper deals with a control approach, based on conservative power commands, which allows selective elimination of the main causes affecting the power quality, i.e., load asymmetry, harmonics, and useless reactive power flow. As a result, distribution efficiency improves, voltage asymmetry and distortion diminishes, and the distribution infrastructure is better exploited, thus allowing an increase of the hosting capacity of the grid.