  A voltage regulation method for slow voltage variations at distribution level
is proposed, based on a view of the loads, generators and storage along a
distribution line as point weights. The "centers of mass" of the absorbed and
injected currents (loads & generation, respectively) are compensated by
minimizing the distance between them, through proper re-dispatching of the
power of the available units and interruptible loads. The technique is
recursively applied to lesser parts of the distribution line to address local
phenomena and is assumed to be offered as ancillary service to the system
operator by a Virtual Power Plant. The favorable results of the methodology are
assessed on a distribution line of the island of Rhodes (Greece) under critical
loading for numerous scenarios. Unlike previous approaches, the technique
focuses specifically in the restoration of bus voltages within standard limits
and may reduce the activation of on-line tap changing transformers control.
