  In recent years, the power systems research community has seen an explosion
of novel methods for formulating the AC power flow equations. Consequently,
benchmarking studies using the seminal AC Optimal Power Flow (AC-OPF) problem
have emerged as the primary method for evaluating these emerging methods.
However, it is often difficult to directly compare these studies due to subtle
differences in the AC-OPF problem formulation as well as the network,
generation, and loading data that are used for evaluation. To help address
these challenges, this IEEE PES Task Force report proposes a standardized
AC-OPF mathematical formulation and the PGLib-OPF networks for benchmarking
AC-OPF algorithms. A motivating study demonstrates some limitations of the
established network datasets in the context of benchmarking AC-OPF algorithms
and a validation study demonstrates the efficacy of using the PGLib-OPF
networks for this purpose. In the interest of scientific discourse and future
additions, the PGLib-OPF benchmark library is open-access and all the of
network data is provided under a creative commons license.
