Moment-based relaxation of the optimal power flow problem

The optimal power flow (OPF) problem minimizes power system operating cost subject to both engineering and network constraints. With the potential to find global solutions, significant research interest has focused on convex relaxations of the non-convex AC OPF problem. This paper investigates "moment-based" relaxations of the OPF problem developed from polynomial optimization theory. At the cost of increased computational requirements, moment relaxations are generally tighter than relaxations employed in previous research, thus resulting in global solutions for a broader class of OPF problems. Exploration of the feasible spaces of test systems illustrates the effectiveness of the moment relaxations.