  The IEEE 1547 Standard for the interconnection of distributed energy
resources (DERs) to distribution grids provisions that smart inverters could be
implementing Volt/VAR control rules among other options. Such rules enable DERs
to respond autonomously in response to time-varying grid loading conditions.
The rules comprise affine droop control augmented with a deadband and
saturation regions. Nonetheless, selecting the shape of these rules is not an
obvious task, and the default options may not be optimal or dynamically stable.
To this end, this work develops a novel methodology for customizing Volt/VAR
rules on a per-bus basis for a single-phase feeder. The rules are adjusted by
the utility every few hours depending on anticipated demand and solar
scenarios. Using a projected gradient descent-based algorithm, rules are
designed to improve the feeder's voltage profile, comply with IEEE 1547
constraints, and guarantee stability of the underlying nonlinear grid dynamics.
The stability region is inner approximated by a polytope and the rules are
judiciously parameterized so their feasible set is convex. Numerical tests
using real-world data on the IEEE 141-bus feeder corroborate the scalability of
the methodology and its explore the trade-offs of Volt/VAR control with
alternatives.
