  This paper considers the problem of voltage regulation in distribution
networks. The primary motivation is to keep voltages within preassigned
operating limits by commanding the reactive power output of distributed energy
resources (DERs) deployed in the grid. We develop a framework for developing
local Volt/Var control that comprises two main steps. In the first, by
exploiting historical data and for each DER, we learn a function representing
the desirable equilibrium points for the power network. These points
approximate solutions of an Optimal Power Flow (OPF) problem. In the second, we
propose a control scheme for steering the network towards these favorable
configurations. Theoretical conditions are derived to formally guarantee the
stability of the developed control scheme, and numerical simulations illustrate
the effectiveness of the proposed approach.
