Incremental Volt/Var Control for Distribution Networks via Chance-Constrained Optimization

This paper considers an incremental Volt/Var control scheme for distribution
systems with high integration of inverter-interfaced distributed generation
(such as photovoltaic systems). The incremental Volt/Var controller is
implemented with the objective of minimizing reactive power usage while
maintaining voltages within safe limits sufficiently often. To this end, the
parameters of the incremental Volt/Var controller are obtained by solving a
chance-constrained optimization problem, where constraints are designed to
ensure that voltage violations do not occur more often than a pre-specified
probability. This approach leads to cost savings in a controlled, predictable
way, while still avoiding significant over- or under-voltage issues. The
proposed chance-constrained problem is solved using a successive convex
approximation method. Once the gains are broadcast to the inverters, no
additional communication is required since the controller is implemented
locally at the inverters. The proposed method is successfully tested on a
low-voltage 42-nodes network.