  The issue of voltage variations caused by integration of renewables has been
addressed in this paper through distributed management of Microgrids (MGs). The
distribution network (DN) takes the network losses and voltage quality as
objectives, an alternating direction method of multipliers (ADMM) with adaptive
penalty modulation has been proposed to realize distributed optimization with
improved convergence. On the basis of satisfying the optimization target on the
system level, the individual MG manages the controllable resources inside the
MG to minimize the operating cost on the lower level. The feasibility and
effectiveness of the proposed method has been demonstrated on a modified IEEE
33-bus system.
