  An effective means for analyzing the impact of novel operating schemes on
power systems is time domain simulation, for example for investigating
optimization-based curtailment of renewables to alleviate voltage violations.
Traditionally, interior-point methods are used for solving the non-convex AC
optimal power flow (OPF) problems arising in this type of simulation. This
paper presents an alternative algorithm that better suits the simulation
framework, because it can more effectively be warm-started, has linear
computational and memory complexity in the problem size per iteration and
globally converges to Karush-Kuhn-Tucker (KKT) points with a linear rate if
they exist. The algorithm exploits a difference-of-convex-functions
reformulation of the OPF problem, which can be performed effectively. Numerical
results are presented comparing the method to state-of-the-art OPF solver
implementations in MATPOWER, leading to significant speedups compared to the
latter.
