  Distributed optimization for solving non-convex Optimal Power Flow (OPF)
problems in power systems has attracted tremendous attention in the last
decade. Most studies are based on the geographical decomposition of IEEE test
systems for verifying the feasibility of the proposed approaches. However, it
is not clear if one can extrapolate from these studies that those approaches
can be applied to very large-scale real-world systems. In this paper, we show,
for the first time, that distributed optimization can be effectively applied to
a large-scale real transmission network, namely, the Polish 2383-bus system for
which no pre-defined partitions exist, by using a recently developed
partitioning technique. More specifically, the problem solved is the AC OPF
problem with geographical decomposition of the network using the Alternating
Direction Method of Multipliers (ADMM) method in conjunction with the
partitioning technique. Through extensive experimental results and analytical
studies, we show that with the presented partitioning technique the convergence
performance of ADMM can be improved substantially, which enables the
application of distributed approaches on very large-scale systems.
