  The objective of electric power system operators is to determine
cost-effective operating points by resolving optimization problems that include
physical and engineering constraints. As empirical evidence and operator
experience indicate, only a small portion of these constraints are found to be
binding during operations. Several optimization-based methods have been
developed to screen out redundant constraints in operational planning problems
like the optimal power flow (OPF) problem. These elimination procedures
primarily focus on the feasible region and ignore the role played by the
problem's objective function. This letter addresses the constraint screening
problem using the bound tightening technique in the context of the OPF problem
formulated with a full ac power flow characterization. Due to the non-convexity
of the ac OPF, we investigate line constraint screening under different convex
relaxations of the problem, and we evaluate how the economics of the objective
function impacts screening outcomes.
