A Two-Level ADMM Algorithm for AC OPF With Global Convergence Guarantees

This paper proposes a two-level distributed algorithmic framework for solving the AC optimal power flow (OPF) problem with convergence guarantees. The presence of highly nonconvex constraints in OPF poses significant challenges to algorithms based on alternating direction method multipliers (ADMM). In particular, is not provably guaranteed network optimization problems like OPF. order overcome this difficulty, we propose new reformulation and ADMM algorithm that goes beyond standard ADMM. We establish global iteration complexity proposed under mild assumptions. Extensive numerical experiments over some largest test cases from NESTA PGLib-OPF (up 30 000-bus systems) demonstrate advantages existing variants terms convergence, scalability, robustness. Moreover, appropriate parallel implementation, exhibits fast comparable or even better than state-of-the-art centralized solver.