Distributed voltage control strategy for LV networks with inverter-interfaced generators

tLow voltage distribution networks are characterized by an ever growing diffusion of single and threephase distributed generators whose unregulated operation may deplete the power quality levels, inparticular as regard voltage profiles and unbalances. This issue is at present under discussion by sev-eral national and international standardization bodies and the general trend is to require, for the newconnections of generators to medium and low voltage grids, their participation to the reactive powernetwork management. In this paper a novel strategy proposes to control the network voltage unbalancesuitably for coordinating single and three-phase inverter interfaced embedded generators, concurrentlywith a local volt/var regulation action as foreseen by the new grid connection requirements. Simulationsconducted on case study network representing a typical Italian 4-wire LV distribution system underdifferent load/generation conditions, demonstrate that the coordinated action of single-phase and three-phase inverters may considerably reduce the degree of unbalance thus improving the network powerquality levels.