Distributed Optimal Power Flow Algorithms Over Time-Varying Communication Networks

In this paper, we consider the problem of optimally coordinating the response of a group of distributed energy resources (DERs) in distribution systems by solving the so-called optimal power flow (OPF) problem. The OPF problem is concerned with determining an optimal operating point, at which total generation cost or power loss is minimized and operational constraints are satisfied. To solve the OPF problem, we propose distributed algorithms that are able to operate over time-varying communication networks and have geometric convergence rate. First, we solve the second-order cone program (SOCP) relaxation of the OPF problem for radial distribution systems, which is formulated using the so-called DistFlow model. Then, we focus on solving the convex relaxation of the OPF problem for mesh distribution systems. Theoretical results are further supported by the numerical simulations.